Vulnerability and childhood immunization in Kenya. A systematic review of policy documents protocol.

Esther Awuor Owino; David Mafigiri; Dorcas Kamuya; Caroline Jones; Primus Chi

doi:10.3310/nihropenres.13449.3

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Revised

Vulnerability and childhood immunization in Kenya. A systematic review of policy documents protocol.

[version 3; peer review: 2 approved, 1 approved with reservations]

Previously titled: Equity, vulnerability and childhood immunization in Kenya and Uganda. A review of policy documents protocol.

Esther Awuor Owino ¹, David Mafigiri², Dorcas Kamuya^1,3, Caroline Jones^1,3, Primus Chi¹

Esther Awuor Owino ¹, David Mafigiri², [...] Dorcas Kamuya^1,3, Caroline Jones^1,3, Primus Chi¹

PUBLISHED 10 Mar 2026

Author details Author details

¹ Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
² Makerere University, Kampala, Central Region, Uganda
³ Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK

Esther Awuor Owino
Roles: Conceptualization, Data Curation, Formal Analysis, Investigation, Methodology, Project Administration, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

David Mafigiri
Roles: Conceptualization, Funding Acquisition, Methodology, Resources, Software, Supervision, Validation, Visualization, Writing – Review & Editing

Dorcas Kamuya
Roles: Conceptualization, Funding Acquisition, Methodology, Resources, Software, Supervision, Validation, Visualization, Writing – Review & Editing

Caroline Jones
Roles: Conceptualization, Funding Acquisition, Methodology, Resources, Software, Supervision, Validation, Visualization, Writing – Review & Editing

Primus Chi
Roles: Conceptualization, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Review & Editing

OPEN PEER REVIEW

REVIEWER STATUS

Abstract

Introduction: Whereas improved full immunization coverage for childhood vaccines have been witnessed globally in the past decades, countries in sub-Saharan Africa have registered slow progress, with variations between and within countries. This has been attributed to several factors including socio-economic, individual and health system vulnerabilities. However, lacking is a documentation of how governments are conceptualizing and addressing these vulnerabilities. We therefore plan to systematically review policy documents to examine the extent to which vulnerability issues are conceptualized and addressed in the general health sector and immunization policy documents in Kenya.

Methods: The review will focus on the general health sector and immunization policy documents covering the period between 2000 and 2023. Documents in the English language will be reviewed. Data sources will include the official Ministry of Health website, websites of key international organizations working on immunization, checking reference lists of already identified documents, general Google searches and requesting relevant documents from stakeholders and officials. Data synthesis will follow an inductive approach, and findings will be presented in a descriptive format according to the review objectives.

Discussion: We will assess the extent to which vulnerability issues are included and how they are defined in the general health sector and immunization policy documents. In addition, the review will examine strategies proposed, planned and/or implemented to promote access and uptake of immunization services in Kenya. Using the review findings, we will formulate recommendations to share with health and Expanded Programme on Immunization (EPI) stakeholders at the national, county, and sub-county levels.

Plain Language Summary

Plain English Summary

Vaccines offer several benefits key among them being prevention of infectious disease outbreaks and deaths. Unfortunately, not everyone enjoys these benefits partly due to avoidable differences in reaching and using vaccines. In most African countries, there have been an increase in the number of those using vaccines over the years even though there are still differences between and within countries. In a bid to ensure that no one is left behind in reaching and using vaccines, most international organizations working around vaccines have now prioritized attaining fairness in use of vaccines and this commitment is reflected in international immunization policy documents. It is therefore important to examine how this is working out at country level. That is whether countries are also working towards ensuring that everyone is vaccinated and whether this is captured in their policy documents. This review therefore seeks to understand what is being done in Kenya and Uganda to ensure that everyone is reached with vaccines by examining key health sector and immunization policy documents.

The review will focus on key health sector and immunization policy documents published in the English language from 2000 to 2023. An online search will be conducted through relevant websites such as ministry of health websites for each country. In addition, documents that cannot be accessed via online sources will be requested from relevant stakeholders in the two countries. The documents will then be screened to determine those appropriate to the review objective. Data from selected documents will be extracted using a data extraction tool, analysed and presented in a descriptive format and in line with the objectives of the review.

Keywords

Equity, immunization, vulnerability, vaccine, vaccination, Kenya, Uganda, policy document review

Corresponding author: Esther Awuor Owino

Competing interests: No competing interests were disclosed.

Grant information: This project is funded by the National Institute for Health and Care Research (NIHR) under its [Global Health Research Units and Groups (GHRUG) Programme (Grant Reference Number NIHR134531)]. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Copyright: © 2026 Owino EA et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

How to cite: Owino EA, Mafigiri D, Kamuya D et al. Vulnerability and childhood immunization in Kenya. A systematic review of policy documents protocol. [version 3; peer review: 2 approved, 1 approved with reservations]. NIHR Open Res 2026, 3:64 (https://doi.org/10.3310/nihropenres.13449.3) First published: 24 Nov 2023, 3:64 (https://doi.org/10.3310/nihropenres.13449.1) Latest published: 10 Mar 2026, 3:64 (https://doi.org/10.3310/nihropenres.13449.3)

Revised Amendments from Version 2

We have revised the manuscript in line with the reviewer's comments. We have revised the title and abstract of the manuscript by providing additional information, including key outputs and a footnote clarifying that this is a review of policy documents rather than published peer-reviewed literature, as advised by the reviewer. We have also revised the plain English summary section to make it more precise. In the introduction section of the manuscript, we have added a definition of the term ‘vulnerability’, recent vaccine coverage data from Kenya and a footnote clarifying the meaning of ‘framing’. In the methods section, we have now provided a justification for including only English documents, information on how we will validate Google searches and a sample of search strings. We have specified the information we intend to extract from the documents and how this information will be synthesised. We have also revised the ethics and bias considerations to acknowledge the potential bias we foresee in the review.

See the authors' detailed response to the review by Patricia Mechael
See the authors' detailed response to the review by Nicholas Spencer
See the authors' detailed response to the review by Morufu Olalekan Raimi

Introduction

Improved health outcomes globally can partly be attributed to the use of vaccines, which have played a significant role in reducing morbidity and mortality arising from life-threatening infectious diseases.^1–3 Over the past decades, several concerted international efforts have been put in place to promote access to and uptake of vaccines targeting different age groups. Key among these was the establishment of the Expanded Programme on Immunization (EPI) by WHO in 1974 and the Global Alliance for Vaccines and Immunization (GAVI) in 1999. These initiatives have so far led to improved childhood vaccination coverage worldwide. However, access and uptake between countries is still characterized by inequities, especially in sub-Saharan Africa where the majority of vaccine-preventable diseases are experienced.^4–6 WHO estimates that more than 30 million children under five years old in Africa suffer from vaccine-preventable diseases annually, out of which 500,000 die from these diseases. This is almost equivalent to 58% of the global burden of vaccine-preventable diseases.² Moreover, many of these children haven’t received any dose of the recommended childhood vaccines. Additionally, immunization coverage at national and sub-national levels in most African countries has stagnated and is disparate.⁶ For instance, in Kenya, the 2022 Kenya Demographic and Health Survey (KHDS) reported full vaccination coverage with basic vaccines at 80%, with Vihiga County reporting the highest coverage of 96% while Garissa County had the lowest coverage of 23%. Furthermore, only 55% of children aged between 12 and 23 months and 38% of those in the age bracket of 24–35 months had been fully vaccinated as per the national immunization schedule.⁷

These disparities not only reflect vulnerabilities influencing access and uptake of vaccines, but also make children experiencing the disparities vulnerable to vaccine-preventable diseases, thereby forming hotspots for future disease outbreaks. Vulnerability has been defined in different ways, as it is rooted in several disciplines. As a concept, vulnerability has been recognised as an inherent human condition due to our embodiment as human beings and affective nature. In addition, vulnerability has been conceptualized as concrete situations arising from multiple, overlapping, dynamic, contextual and multidimensional factors including individual, social and structural dimensions. For instance, Grabovschi et al. (2013) in their review of mapping the concept of vulnerability related to healthcare disparities operationalized vulnerability as an increased susceptibility to health and health care disparities due to several factors at the individual and environmental level.⁸ They defined individual-level factors as either inborn (sex, race, genetic predispositions to disease) or acquired (trauma, diseases, lifestyle). On the other hand, environmental factors included those in the immediate physical environment or the broader socio-economic environment.

Several reviews of published literature have been conducted to highlight vulnerabilities that influence the disparities in access and uptake of childhood vaccines.^9,10 For instance, in Kenya, previous studies have shown that children’s vulnerability to vaccine-related disparities is influenced by geographical, household, and mothers’ characteristics.^11,12 However, reviews on how these vulnerability issues are addressed in grey literature, such as government policies, are lacking. Yet this understanding is not only important but also necessary for the identification of gaps and the formulation of appropriate strategies to ensure access and uptake. We therefore intend to systematically review general health sector and immunisation-specific policy documents in Kenya to examine the extent to which vulnerability issues are framed [2] and addressed generally and in the context of immunization. Specifically, the review will: (1) describe how vulnerability is defined and components considered in the general health sector and immunisation-specific policy documents, and (2) examine strategies proposed in the policy documents to address vulnerability issues in general and in the context of immunization.

Methods

Inclusion criteria

The documents to be reviewed will include general health sector and immunization specific policies, guidelines and strategic plans. Only documents in the English language will be included given that English is the primary language for official government policy documentation, especially for national and county-level strategies, policies and plans in Kenya. In addition, including only English policy documents is necessary to ensure consistent interpretation of the policy documents. Publication date for inclusion will be from 2000 (to correspond with the establishment of GAVI, which has played a key role in promoting access to vaccines in most of the developing countries like Kenya) to 2023.

Information sources

Documents to be reviewed will be retrieved from the following sources:

i. The official Kenyan Ministry of Health website (https://www.health.go.ke/).
ii. Websites of international and local organizations working around childhood immunization in Kenya e.g., UNICEF, GAVI, WHO, Save the Children etc (https://www.unicef.org/; https://www.gavi.org/; https://www.who.int/; https://kenya.savethechildren.net/)
iii. Requesting for relevant documents from the relevant stakeholders at MOH, Kilifi County department of health and donor and partner organizations.
iv. Reference list of included documents.
v. General google search.

Google search results will be screened for relevance based on alignment with the study objectives and inclusion criteria. Only documents published by official government institutions and recognized international health organizations will be prioritized.

Search strategy

The following keywords will be used for general Google searches as well as the specific websites listed above: Vaccin* and/or immuniz* AND/OR routine vaccin* and/or immuniz* and/or vulnerab* AND/OR Expanded programme on immunization or EPI OR Kenya expanded programme on immunization or KEPI. Sample search strings will include: (Vaccin* OR immuniz*) AND Kenya; (routine vaccin* OR routine immuniz*) AND Kenya; (Vaccin* OR immuniz*) AND (vulnerab* OR marginalized) AND Kenya; (routine vaccin* OR routine immuniz*) AND (“Expanded Programme on Immunization” OR EPI OR KEPI).

In addition to the search strategy presented above, documents will also be identified from the reference lists of the identified documents.

Study records

Data management and selection process. All documents retrieved from online sources will be exported and managed in Endnote v20 or Mendeley where duplicates will also be identified. The reviewer (EO) will manually screen the documents to identify those relevant to the review questions and that meet the eligibility criteria. The screening will be based on the title of the document, a search of terms, including vulnerability, immunization, and vaccination within the documents, and by reading through the executive summary of a document. We don’t intend to apply formal inter-rater reliability measures (e.g., Cohen’s Kappa); however, to ensure consistency and quality control, screening decisions and the list of documents identified as eligible for review will be shared with the PC, CJ, DM and DK for verification. EO and PC, CJ, DM and DK will then meet to discuss the appropriateness of the documents identified as eligible. During these meetings, any disagreements will be discussed, and a consensus will be reached on documents to be included for final review. The process of selecting relevant documents for review will be summarized using a PRISMA-style flow diagram, detailing the number of documents identified, screened, included, and excluded, along with reasons for exclusion.

Data collection process and data items. Data collection will be performed by EO using a data extraction template.¹³ The extracted data will then be shared with co-reviewers, who will independently review it. Afterwards, the team will meet to discuss and resolve any disagreements. The data extraction tool will be developed using an Excel spreadsheet. Each row of the tool will capture the identified documents, while the individual columns will capture the types of information to extract from them. Information to be extracted will include general information about the documents, e.g., the full title of the document, author(s), date of publication, purpose of the document, intended users/audience and a summary of issues addressed in the document. The second category of information to be extracted will include how vulnerability is defined, who is considered vulnerable and strategies to address the needs of those considered vulnerable. To extract this type of data, a full-text review of documents that are entirely focused on immunization will be conducted, while for documents that contain other information apart from immunization, only relevant sections will be read and data extracted, in addition to the general information about the document.

Review outcomes

The key outcomes for this review will be a description of how vulnerability issues have been conceptualized in immunization and health sector policy documents in Kenya, strategies planned and/or implemented by the Kenyan government to address health-related vulnerabilities and those specific to access and uptake of vaccines in the policy documents reviewed. Findings from this review will be shared with relevant stakeholders through policy briefs and dissemination meetings and explored further through primary research focusing on vulnerabilities influencing childhood vaccination in Kenya.

Risk of bias in individual studies

Although every effort will be made to secure all relevant documents for the review, we recognize that we may miss unpublished or documents that are still being drafted. Also the review findings will be limited to data drawn from policy documents which fall within the inclusion criteria (only English documents, and those published from 2000–2023).

Data synthesis

Data synthesis will follow an inductive approach where the extracted data on vulnerability will be read line by line and appropriate codes applied in Nvivo 12 software. Data will then be organized thematically to address the review objectives: how vulnerability issues are conceptualized/defined, aspects considered in the documents and strategies proposed to address vulnerability issues. The themes developed will be reviewed and revised through comparison across documents, and any discrepancies will be discussed amongst reviewers until a consensus is reached.

Meta-bias(es)

Not applicable.

Confidence in cumulative evidence

Not applicable.

Study status

Completion of this review is anticipated to be by September 2023. The study team is currently screening documents identified through online searches.

Conclusion

The review intends to provide an understanding of vulnerability issues in the context of health and immunization in Kenya. Specifically, it will focus on how vulnerability issues are framed in policy documents to identify gaps and opportunities that can be harnessed to address vulnerabilities that influence access and uptake of vaccines. We intend to explore the gaps identified through the review with relevant stakeholders through primary research and contribute to the improvement of the policy landscape around immunization by sharing the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels.

Data availability

Extended data

Harvard Dataverse: Equity, vulnerability and childhood immunization in Kenya and Uganda: a systematic review of policy documents protocol. https://doi.org/10.7910/DVN/GZOQTL.

This project contains the following extended data:

• Extended data file 1. PRISMA-P checklist (The checklist reports items addressed in this systematic review protocol).
• Extended data file 2. Data extraction template (This data extraction template will be used to manually extract relevant data from the documents included for analysis as per the review objectives)

Data are available under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0).

Reporting guidelines

A PRISMA-P checklist has been completed and uploaded on Harvard Dataverse. https://doi.org/10.7910/DVN/GZOQTL.

References

1. Doughty HC, Hill RA, Riley A, et al.: Barriers to and facilitators of physical activity in adults living with and beyond cancer, with special emphasis on head and neck cancer: a systematic review of qualitative and mixed methods studies. Support Care Cancer. 2023; 31(8): 471. PubMed Abstract | Publisher Full Text
2. World Health Organzation (WHO): Explorations of inequality: Childhood immunization. 2018.
3. Rodrigues CMC, Plotkin SA: Impact of Vaccines; Health, Economic and Social Perspectives. Front Microbiol. 2020; 11: 1526. Publisher Full Text
4. World Health Organization (WHO): Regional Strategic Plan for Immunization 2014–2020. 2015.
5. Kaur G, et al. Routine Vaccination Coverage — Worldwide, 2022. 2023 [cited 2024 Feb 20, 2024]. https://www.cdc.gov/mmwr/volumes/72/wr/mm7243a1.htm
6. Ikilezi G, Augusto OJ, Sbarra A, et al.: Determinants of geographical inequalities for DTP3 vaccine coverage in sub-Saharan Africa. Vaccine. 2020; 38(18): 3447–3454. PubMed Abstract | Publisher Full Text
7. Kenya National Bureau of Statistics (KNBS):Kenya Demographic and Health Survey 2022. 2023.
8. Grabovschi C, Loignon C, Fortin M: Mapping the concept of vulnerability related to health care disparities: A scoping review. BMC Health Serv Res. 2013; 13(94).
9. Bangura JB, Xiao S, Qiu D, et al.: Barriers to childhood immunization in sub-Saharan Africa: A systematic review. BMC Public Health. 2020; 20(1): 1108. PubMed Abstract | Publisher Full Text | Free Full Text
10. Galadima AN, Zulkefli NAM, Said SM, et al.: Factors influencing childhood immunisation uptake in Africa: a systematic review. BMC Public Health. 2021; 21(1): 1475. PubMed Abstract | Publisher Full Text | Free Full Text
11. Allan S, Adetifa IMO, Abbas K: Inequities in childhood immunisation coverage associated with socioeconomic, geographic, maternal, child, and place of birth characteristics in Kenya. BMC Infect Dis. 2021; 21(1): 553. PubMed Abstract | Publisher Full Text | Free Full Text
12. Mutua MK, et al.: Fully immunized child: coverage, timing and sequencing of routine immunization in an urban poor settlement in Nairobi, Kenya. Trop Med Health. 2016; 44(13).
13. Owino E, Mafigiri D, Kamuya D, et al.: Equity, vulnerability and childhood immunization in Kenya and Uganda. A review of policy documents protocol. NIHR Open Res. 2023; 3. Publisher Full Text

Footnotes

1 Systematic review here refers to a review of policy documents and not a review of published peer-reviewed literature

2 Here framing refers to how vulnerability is defined and operationalized as well as components considered.

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Version 3

VERSION 3 PUBLISHED 24 Nov 2023

Author details Author details

David Mafigiri
Roles: Conceptualization, Funding Acquisition, Methodology, Resources, Software, Supervision, Validation, Visualization, Writing – Review & Editing

Dorcas Kamuya
Roles: Conceptualization, Funding Acquisition, Methodology, Resources, Software, Supervision, Validation, Visualization, Writing – Review & Editing

Caroline Jones
Roles: Conceptualization, Funding Acquisition, Methodology, Resources, Software, Supervision, Validation, Visualization, Writing – Review & Editing

Primus Chi
Roles: Conceptualization, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing – Review & Editing

Competing interests

No competing interests were disclosed.

Grant information

This project is funded by the National Institute for Health and Care Research (NIHR) under its [Global Health Research Units and Groups (GHRUG) Programme (Grant Reference Number NIHR134531)]. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Article Versions (3)

version 3

Revised

Published: 10 Mar 2026, 3:64

https://doi.org/10.3310/nihropenres.13449.3

version 2

Revised

Published: 27 May 2025, 3:64

https://doi.org/10.3310/nihropenres.13449.2

version 1

Published: 24 Nov 2023, 3:64

https://doi.org/10.3310/nihropenres.13449.1

© 2026 Owino EA et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Owino EA, Mafigiri D, Kamuya D et al. Vulnerability and childhood immunization in Kenya. A systematic review of policy documents protocol. [version 3; peer review: 2 approved, 1 approved with reservations]. NIHR Open Res 2026, 3:64 (https://doi.org/10.3310/nihropenres.13449.3)

NOTE: If applicable, it is important to ensure the information in square brackets after the title is included in all citations of this article.

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Open Peer Review

Current Reviewer Status: ?

Key to Reviewer Statuses VIEW HIDE

ApprovedThe paper is scientifically sound in its current form and only minor, if any, improvements are suggested

Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit.

Not approvedFundamental flaws in the paper seriously undermine the findings and conclusions

Version 3

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PUBLISHED 10 Mar 2026

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Reviewer Report 12 Mar 2026

Nicholas Spencer, University of Warwick, Coventry, England, UK

Approved

https://doi.org/10.3310/nihropenres.15530.r39927

The authors have revised the paper in line with my suggestions and those ... Continue reading

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Version 2

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PUBLISHED 27 May 2025

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Reviewer Report 04 Nov 2025

Morufu Olalekan Raimi, Federal University Otuoke, Otuoke, Nigeria

Approved with Reservations

https://doi.org/10.3310/nihropenres.15217.r36147

A. GENERAL EVALUATION
This protocol addresses an urgent global health equity issue, the inclusion (or exclusion) of vulnerability in policy frameworks guiding childhood immunization in Kenya. It is conceptually timely and methodologically appropriate for shaping more equitable vaccine strategies. ... Continue reading

Insufficient methodological detail for full replication,
A lack of conceptual clarity around “vulnerability,”
Overuse of generic phrasing without sufficient policy analysis theory grounding,
Structural inconsistencies (e.g., ambiguous timelines, redundancy in explanation).

This review presents detailed paragraph-level feedback, followed by overall recommendations.

B. DETAILED SECTION-BY-SECTION REVIEW

1. Title and Abstract

The revised title is clearer and better aligned with the focus on Kenya and “vulnerability.” Abstract introduces rationale, methods, and aims adequately.

The term “systematic review” remains potentially misleading for policy documents. Though addressed in previous peer reviews, a footnote or clarification on the nature of this “review” (policy document analysis vs. intervention or clinical trial) may still be helpful.
The sentence “...this has been attributed to several challenges/vulnerability factors” is vague. Use more precise terms (e.g., geographic inequality, socio-economic status, maternal education, etc.). Author should consider “systematic policy review” or “document analysis” as part of the subtitle.

Add 1-2 key expected outputs (e.g., frameworks, recommendations) in the abstract.

2. Plain English Summary

Simplifies technical content for lay readers effectively and gives a clear sense of relevance and practical application. Contains overly long and repetitive sentences.

The last paragraph restates the same information from the abstract almost verbatim. Example: “...examine how this is working out at country level...whether this is captured in their policy documents.” This can be shortened and rephrased for clarity. Author should trim redundancy; group benefits, equity aims, and method into clearer subsections as well as add clarity on the population of interest (e.g., age ranges, vulnerable groups).

3. Introduction

Strong justification for immunization as a public health strategy and use of global data and WHO sources improves credibility. Many sentences are generic and overstate well-known facts (e.g., “Vaccines...prevent disease outbreaks and deaths”). Author should cite specific immunization coverage stats from Kenya to better localize the narrative (e.g., coverage in counties like Turkana vs. Nairobi).

Cites previous reviews and identifies literature gaps effectively. The claim: “how these vulnerability issues are framed...in grey literature...is lacking” is weak without citing national health policies or strategies reviewed in prior studies. Author should cite at least 1-2 key documents (e.g., Kenya Health Policy 2014–2030) to support this gap. Expand on what “framing” means, define whether it's inclusion, prioritization, or operationalization of vulnerability.

4. Methods
Inclusion Criteria:

Temporal scope (2000–2023) is justified and aligns with GAVI-era reforms and language and type of documents are clearly listed. The rationale for focusing solely on English-language documents could be expanded upon given potential inclusion of Kiswahili policy texts.

Information Sources & Search Strategy:

Multiple source types are considered, from MOH websites to gray literature and personal contacts. No detail is provided on how the Google searches will be validated for relevance, or how source credibility will be assessed. Author should add a sample search string (already suggested by a previous reviewer) and include a visual flow diagram (e.g., PRISMA-style chart) in the final paper.

Study Records, Data Management & Selection:

Use of EndNote/Mendeley and consensus screening is appropriate. No mention of whether inter-rater reliability or agreement measures (e.g., Cohen’s Kappa) will be used. Author should clarify the criteria for resolving disagreements during screening as well as specify who will perform quality control and ensure consistency.

Data Collection and Extraction:

Inclusion of a data extraction template is commendable and enhances transparency.

The explanation of what constitutes “explicit and implicit” vulnerability-related information is vague. Author should define indicators of implicit vulnerability (e.g., mention of remote populations, nomadic groups, maternal illiteracy) and consider aligning categories with a policy analysis framework such as Walt & Gilson’s policy triangle.

Review Outcomes:

Clearly articulated: framing, strategies, gaps, and opportunities. “Gaps and opportunities” are vague without examples of potential policy levers (e.g., funding, service delivery). Author should mention potential uses of findings (e.g., stakeholder engagement, policy briefs).

5. Data Synthesis

Inductive thematic analysis is appropriate for qualitative document review. No mention of NVivo or qualitative coding software to manage complex themes. Author should consider using software like NVivo or Atlas.ti for theme development and outline how themes will be validated or revised.

6. Ethics & Bias Consideration

Noted as “Not applicable” for risk of bias/meta-bias. While true for empirical bias, the risk of selection bias in policy document inclusion exists and is not addressed. Author should add a paragraph in the discussion acknowledging this limitation e.g., exclusion of unpublished or draft policies.

7. Conclusion

Emphasizes intended use of findings to influence policy. Too generic. Does not outline how findings will be shared, with whom, and for what purpose. Hence, Author should add specifics: “We will share findings with the Kenya EPI taskforce, civil society actors, and Ministry of Health policymakers through workshops and briefings.”

8. Extended Data & Reporting

Inclusion of PRISMA-P and a data extraction template shows protocol rigor. Author should ensure that the final publication also includes:

PRISMA flow diagram.
A sample of coded policy excerpts in supplementary material.

C. OVERALL STRENGTHS

Responds well to previous reviews and narrows its scope effectively.
Clearly structured protocol with transparent data collection and extraction plans.
Solid foundation for future primary research on immunization access in Kenya.

D. AREAS NEEDING REVISION
Area
Recommendations
Conceptual Clarity
Define “vulnerability” more rigorously; use a guiding policy framework (e.g., WHO’s equity lens).

Search Strategy
Include a sample string and Google search filtering criteria.

Data Extraction & Coding
Add criteria for identifying implicit mentions; consider coding software.

Risk of Bias
Discuss selection bias from document inclusion and relevance thresholds.

Conclusion
Specify dissemination pathways and intended policy impact more explicitly.

Recommendation: Moderate Revision

Is the rationale for, and objectives of, the study clearly described?

Yes
Is the study design appropriate for the research question?

Yes
Are sufficient details of the methods provided to allow replication by others?

Yes
Are the datasets clearly presented in a useable and accessible format?

Yes

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Environmental Epidemiology; Climate Change and Health; Pollution Control Management; Public Health; Groundwater Quality

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.

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Author Response 10 Mar 2026

Esther Owino, Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya

10 Mar 2026

Author Response

Thank you very much Dr Morufu Olalekan Raimi, for taking the time to review our manuscript. We truly appreciate your valuable and useful feedback and comments. Below, please find our responses to ... Continue reading Thank you very much Dr Morufu Olalekan Raimi, for taking the time to review our manuscript. We truly appreciate your valuable and useful feedback and comments. Below, please find our responses to the issues you raised.

Title and abstract
1. The revised title is clearer and better aligned with the focus on Kenya and “vulnerability.” Abstract introduces rationale, methods, and aims adequately. The term “systematic review” remains potentially misleading for policy documents. Though addressed in previous peer reviews, a footnote or clarification on the nature of this “review” (policy document analysis vs. intervention or clinical trial) may still be helpful.
Response: We have added a footnote to clarify that this is a review of policy documents and not published peer-reviewed literature.

2. The sentence “...this has been attributed to several challenges/vulnerability factors” is vague. Use more precise terms (e.g., geographic inequality, socio-economic status, maternal education, etc.). Author should consider “systematic policy review” or “document analysis” as part of the subtitle.

Response: We have included more precise terms (socio-economic, individual and health system vulnerabilities)

3. Add 1-2 key expected outputs (e.g., frameworks, recommendations) in the abstract.

Response: We have indicated that using the review findings, we will formulate recommendations to be shared with health and EPI stakeholders at the national, county and sub-county levels.

Plain English Summary
4: Simplifies technical content for lay readers effectively and gives a clear sense of relevance and practical application. Contains overly long and repetitive sentences.

Response: We have revised the plain English summary to be more precise

Introduction
5. Many sentences are generic and overstate well-known facts (e.g., “Vaccines...prevent disease outbreaks and deaths”). Author should cite specific immunization coverage stats from Kenya to better localize the narrative (e.g., coverage in counties like Turkana vs. Nairobi).

Response: To illustrate the disparities within the country, we have provided the recent vaccine coverage data from the 2022 Kenya Demographic and Health Survey (KHDS).

6. Expand on what “framing” means, define whether it's inclusion, prioritization, or operationalization of vulnerability.
Response: A footnote has been added to expand on what we mean by “framing”. In this protocol, framing refers to how vulnerability is defined and operationalized as well as components considered.

Methods
7. The rationale for focusing solely on English-language documents could be expanded upon given potential inclusion of Kiswahili policy texts.
Response: We have expanded on the rationale of focusing on the English documents, which is because English is the primary language for official government policy documentation, especially for national and county-level strategies, policies and plans in Kenya. In addition, we have included only English policy documents to ensure consistent interpretation of the policy documents.

8. No detail is provided on how the Google searches will be validated for relevance, or how source credibility will be assessed. Author should add a sample search string (already suggested by a previous reviewer) and include a visual flow diagram (e.g., PRISMA-style chart) in the final paper.
Response: To validate Google searches, Google search results will be screened for relevance based on alignment with the study objectives and inclusion criteria. Only documents published by official government institutions and recognized international health organizations will be prioritized. A sample of search search strings will include Vaccin* OR immuniz*) AND Kenya; (routine vaccin* OR routine immuniz*) AND Kenya; (Vaccin* OR immuniz*) AND (vulnerab* OR marginalized) AND Kenya; (routine vaccin* OR routine immuniz*) AND ("Expanded Programme on Immunization" OR EPI OR KEPI).

9. No mention of whether inter-rater reliability or agreement measures (e.g., Cohen’s Kappa) will be used. Author should clarify the criteria for resolving disagreements during screening as well as specify who will perform quality control and ensure consistency.
Response: Whereas we don’t intend to use formal inter-rater reliability measures (e.g., Cohen’s Kappa in this review, the team will hold meetings to discuss the relevance of documents to be included for review and any disagreements addressed during the discussions.

10. The explanation of what constitutes “explicit and implicit” vulnerability-related information is vague. Author should define indicators of implicit vulnerability (e.g., mention of remote populations, nomadic groups, maternal illiteracy) and consider aligning categories with a policy analysis framework such as Walt & Gilson’s policy triangle.
Response: We have spelt out the specific information on vulnerability that we intend to extract. This will be how vulnerability is defined, who is considered vulnerable and strategies to address the needs of those considered vulnerable. As for the use of a policy analysis framework such as Walt & Gilson’s policy triangle, in this review we only plan to synthesise the content of policy documents.

11. The author should mention potential uses of findings (e.g., stakeholder engagement, policy briefs).
Response: We have added information on how we intend to use the findings of the review. Our plan is to share the review findings with stakeholders through policy briefs and dissemination meetings and explore further through primary research focusing on vulnerabilities influencing childhood vaccination in Kenya.

12. No mention of NVivo or qualitative coding software to manage complex themes. Author should consider using software like NVivo or Atlas.ti for theme development and outline how themes will be validated or revised.
Response: We have included use of Nvivo software and the themes will be reviewed and revised through comparison across documents, and any discrepancies will be discussed amongst reviewers until a consensus is reached.

13. Author should add a paragraph in the discussion acknowledging this limitation e.g., exclusion of unpublished or draft policies.
Response: We have outlined the biases we foresee in our review. These include: possibility of missing out on some of the documents that are not publicly available online and those still in the drafting stages. We also recognize that our findings will be limited to documents that fall within the inclusion criteria.

14. Conclusion: Emphasizes intended use of findings to influence policy. Too generic. Does not outline how findings will be shared, with whom, and for what purpose. Hence, Author should add specifics: “We will share findings with the Kenya EPI taskforce, civil society actors, and Ministry of Health policymakers through workshops and briefings.”
Response: In the revised conclusion, we have specified that we will share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels.

Areas needing revision

15. Conceptual Clarity: Define “vulnerability” more rigorously; use a guiding policy framework (e.g., WHO’s equity lens).
Response: We have provided the following definition of vulnerability in the introduction section

16. Search Strategy: Include a sample string and Google search filtering criteria.
Response: This has been addressed by including a sample search string. We have also indicated that Google searches will be screened for suitability based on their alignment with review objectives and inclusion criteria. We will also only consider documents published by official government institutions and recognized international health organizations.

17. Data Extraction & Coding: Add criteria for identifying implicit mentions; consider coding software.
Response: We have specified the information we intend to extract from the documents and also added the use of NVivo software.

18: Risk of Bias: Discuss selection bias from document inclusion and relevance thresholds.
Response: Under the risk and bias section, we have indicated that potential risks of bias including missing unpublished or documents that are still being drafted and those that fall within the inclusion criteria (only English documents, and those published from 2000-2023).

19. Conclusion: Specify dissemination pathways and intended policy impact more explicitly.
We plan to share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels to contribute to the improvement of the immunization policy landscape in Kenya.
Thank you very much Dr Morufu Olalekan Raimi, for taking the time to review our manuscript. We truly appreciate your valuable and useful feedback and comments. Below, please find our responses to the issues you raised.

Title and abstract
1. The revised title is clearer and better aligned with the focus on Kenya and “vulnerability.” Abstract introduces rationale, methods, and aims adequately. The term “systematic review” remains potentially misleading for policy documents. Though addressed in previous peer reviews, a footnote or clarification on the nature of this “review” (policy document analysis vs. intervention or clinical trial) may still be helpful.
Response: We have added a footnote to clarify that this is a review of policy documents and not published peer-reviewed literature.

2. The sentence “...this has been attributed to several challenges/vulnerability factors” is vague. Use more precise terms (e.g., geographic inequality, socio-economic status, maternal education, etc.). Author should consider “systematic policy review” or “document analysis” as part of the subtitle.

Response: We have included more precise terms (socio-economic, individual and health system vulnerabilities)

3. Add 1-2 key expected outputs (e.g., frameworks, recommendations) in the abstract.

Response: We have indicated that using the review findings, we will formulate recommendations to be shared with health and EPI stakeholders at the national, county and sub-county levels.

Plain English Summary
4: Simplifies technical content for lay readers effectively and gives a clear sense of relevance and practical application. Contains overly long and repetitive sentences.

Response: We have revised the plain English summary to be more precise

Introduction
5. Many sentences are generic and overstate well-known facts (e.g., “Vaccines...prevent disease outbreaks and deaths”). Author should cite specific immunization coverage stats from Kenya to better localize the narrative (e.g., coverage in counties like Turkana vs. Nairobi).

Response: To illustrate the disparities within the country, we have provided the recent vaccine coverage data from the 2022 Kenya Demographic and Health Survey (KHDS).

6. Expand on what “framing” means, define whether it's inclusion, prioritization, or operationalization of vulnerability.
Response: A footnote has been added to expand on what we mean by “framing”. In this protocol, framing refers to how vulnerability is defined and operationalized as well as components considered.

Methods
7. The rationale for focusing solely on English-language documents could be expanded upon given potential inclusion of Kiswahili policy texts.
Response: We have expanded on the rationale of focusing on the English documents, which is because English is the primary language for official government policy documentation, especially for national and county-level strategies, policies and plans in Kenya. In addition, we have included only English policy documents to ensure consistent interpretation of the policy documents.

8. No detail is provided on how the Google searches will be validated for relevance, or how source credibility will be assessed. Author should add a sample search string (already suggested by a previous reviewer) and include a visual flow diagram (e.g., PRISMA-style chart) in the final paper.
Response: To validate Google searches, Google search results will be screened for relevance based on alignment with the study objectives and inclusion criteria. Only documents published by official government institutions and recognized international health organizations will be prioritized. A sample of search search strings will include Vaccin* OR immuniz*) AND Kenya; (routine vaccin* OR routine immuniz*) AND Kenya; (Vaccin* OR immuniz*) AND (vulnerab* OR marginalized) AND Kenya; (routine vaccin* OR routine immuniz*) AND ("Expanded Programme on Immunization" OR EPI OR KEPI).

9. No mention of whether inter-rater reliability or agreement measures (e.g., Cohen’s Kappa) will be used. Author should clarify the criteria for resolving disagreements during screening as well as specify who will perform quality control and ensure consistency.
Response: Whereas we don’t intend to use formal inter-rater reliability measures (e.g., Cohen’s Kappa in this review, the team will hold meetings to discuss the relevance of documents to be included for review and any disagreements addressed during the discussions.

10. The explanation of what constitutes “explicit and implicit” vulnerability-related information is vague. Author should define indicators of implicit vulnerability (e.g., mention of remote populations, nomadic groups, maternal illiteracy) and consider aligning categories with a policy analysis framework such as Walt & Gilson’s policy triangle.
Response: We have spelt out the specific information on vulnerability that we intend to extract. This will be how vulnerability is defined, who is considered vulnerable and strategies to address the needs of those considered vulnerable. As for the use of a policy analysis framework such as Walt & Gilson’s policy triangle, in this review we only plan to synthesise the content of policy documents.

11. The author should mention potential uses of findings (e.g., stakeholder engagement, policy briefs).
Response: We have added information on how we intend to use the findings of the review. Our plan is to share the review findings with stakeholders through policy briefs and dissemination meetings and explore further through primary research focusing on vulnerabilities influencing childhood vaccination in Kenya.

12. No mention of NVivo or qualitative coding software to manage complex themes. Author should consider using software like NVivo or Atlas.ti for theme development and outline how themes will be validated or revised.
Response: We have included use of Nvivo software and the themes will be reviewed and revised through comparison across documents, and any discrepancies will be discussed amongst reviewers until a consensus is reached.

13. Author should add a paragraph in the discussion acknowledging this limitation e.g., exclusion of unpublished or draft policies.
Response: We have outlined the biases we foresee in our review. These include: possibility of missing out on some of the documents that are not publicly available online and those still in the drafting stages. We also recognize that our findings will be limited to documents that fall within the inclusion criteria.

14. Conclusion: Emphasizes intended use of findings to influence policy. Too generic. Does not outline how findings will be shared, with whom, and for what purpose. Hence, Author should add specifics: “We will share findings with the Kenya EPI taskforce, civil society actors, and Ministry of Health policymakers through workshops and briefings.”
Response: In the revised conclusion, we have specified that we will share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels.

Areas needing revision

15. Conceptual Clarity: Define “vulnerability” more rigorously; use a guiding policy framework (e.g., WHO’s equity lens).
Response: We have provided the following definition of vulnerability in the introduction section

16. Search Strategy: Include a sample string and Google search filtering criteria.
Response: This has been addressed by including a sample search string. We have also indicated that Google searches will be screened for suitability based on their alignment with review objectives and inclusion criteria. We will also only consider documents published by official government institutions and recognized international health organizations.

17. Data Extraction & Coding: Add criteria for identifying implicit mentions; consider coding software.
Response: We have specified the information we intend to extract from the documents and also added the use of NVivo software.

18: Risk of Bias: Discuss selection bias from document inclusion and relevance thresholds.
Response: Under the risk and bias section, we have indicated that potential risks of bias including missing unpublished or documents that are still being drafted and those that fall within the inclusion criteria (only English documents, and those published from 2000-2023).

19. Conclusion: Specify dissemination pathways and intended policy impact more explicitly.
We plan to share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels to contribute to the improvement of the immunization policy landscape in Kenya.
Competing Interests: No competing interests were disclosed. Close
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COMMENTS ON THIS REPORT

Author Response 10 Mar 2026

Esther Owino, Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya

10 Mar 2026

Author Response

Thank you very much Dr Morufu Olalekan Raimi, for taking the time to review our manuscript. We truly appreciate your valuable and useful feedback and comments. Below, please find our responses to ... Continue reading Thank you very much Dr Morufu Olalekan Raimi, for taking the time to review our manuscript. We truly appreciate your valuable and useful feedback and comments. Below, please find our responses to the issues you raised.

Title and abstract
1. The revised title is clearer and better aligned with the focus on Kenya and “vulnerability.” Abstract introduces rationale, methods, and aims adequately. The term “systematic review” remains potentially misleading for policy documents. Though addressed in previous peer reviews, a footnote or clarification on the nature of this “review” (policy document analysis vs. intervention or clinical trial) may still be helpful.
Response: We have added a footnote to clarify that this is a review of policy documents and not published peer-reviewed literature.

2. The sentence “...this has been attributed to several challenges/vulnerability factors” is vague. Use more precise terms (e.g., geographic inequality, socio-economic status, maternal education, etc.). Author should consider “systematic policy review” or “document analysis” as part of the subtitle.

Response: We have included more precise terms (socio-economic, individual and health system vulnerabilities)

3. Add 1-2 key expected outputs (e.g., frameworks, recommendations) in the abstract.

Response: We have indicated that using the review findings, we will formulate recommendations to be shared with health and EPI stakeholders at the national, county and sub-county levels.

Plain English Summary
4: Simplifies technical content for lay readers effectively and gives a clear sense of relevance and practical application. Contains overly long and repetitive sentences.

Response: We have revised the plain English summary to be more precise

Introduction
5. Many sentences are generic and overstate well-known facts (e.g., “Vaccines...prevent disease outbreaks and deaths”). Author should cite specific immunization coverage stats from Kenya to better localize the narrative (e.g., coverage in counties like Turkana vs. Nairobi).

Response: To illustrate the disparities within the country, we have provided the recent vaccine coverage data from the 2022 Kenya Demographic and Health Survey (KHDS).

6. Expand on what “framing” means, define whether it's inclusion, prioritization, or operationalization of vulnerability.
Response: A footnote has been added to expand on what we mean by “framing”. In this protocol, framing refers to how vulnerability is defined and operationalized as well as components considered.

Methods
7. The rationale for focusing solely on English-language documents could be expanded upon given potential inclusion of Kiswahili policy texts.
Response: We have expanded on the rationale of focusing on the English documents, which is because English is the primary language for official government policy documentation, especially for national and county-level strategies, policies and plans in Kenya. In addition, we have included only English policy documents to ensure consistent interpretation of the policy documents.

8. No detail is provided on how the Google searches will be validated for relevance, or how source credibility will be assessed. Author should add a sample search string (already suggested by a previous reviewer) and include a visual flow diagram (e.g., PRISMA-style chart) in the final paper.
Response: To validate Google searches, Google search results will be screened for relevance based on alignment with the study objectives and inclusion criteria. Only documents published by official government institutions and recognized international health organizations will be prioritized. A sample of search search strings will include Vaccin* OR immuniz*) AND Kenya; (routine vaccin* OR routine immuniz*) AND Kenya; (Vaccin* OR immuniz*) AND (vulnerab* OR marginalized) AND Kenya; (routine vaccin* OR routine immuniz*) AND ("Expanded Programme on Immunization" OR EPI OR KEPI).

9. No mention of whether inter-rater reliability or agreement measures (e.g., Cohen’s Kappa) will be used. Author should clarify the criteria for resolving disagreements during screening as well as specify who will perform quality control and ensure consistency.
Response: Whereas we don’t intend to use formal inter-rater reliability measures (e.g., Cohen’s Kappa in this review, the team will hold meetings to discuss the relevance of documents to be included for review and any disagreements addressed during the discussions.

10. The explanation of what constitutes “explicit and implicit” vulnerability-related information is vague. Author should define indicators of implicit vulnerability (e.g., mention of remote populations, nomadic groups, maternal illiteracy) and consider aligning categories with a policy analysis framework such as Walt & Gilson’s policy triangle.
Response: We have spelt out the specific information on vulnerability that we intend to extract. This will be how vulnerability is defined, who is considered vulnerable and strategies to address the needs of those considered vulnerable. As for the use of a policy analysis framework such as Walt & Gilson’s policy triangle, in this review we only plan to synthesise the content of policy documents.

11. The author should mention potential uses of findings (e.g., stakeholder engagement, policy briefs).
Response: We have added information on how we intend to use the findings of the review. Our plan is to share the review findings with stakeholders through policy briefs and dissemination meetings and explore further through primary research focusing on vulnerabilities influencing childhood vaccination in Kenya.

12. No mention of NVivo or qualitative coding software to manage complex themes. Author should consider using software like NVivo or Atlas.ti for theme development and outline how themes will be validated or revised.
Response: We have included use of Nvivo software and the themes will be reviewed and revised through comparison across documents, and any discrepancies will be discussed amongst reviewers until a consensus is reached.

13. Author should add a paragraph in the discussion acknowledging this limitation e.g., exclusion of unpublished or draft policies.
Response: We have outlined the biases we foresee in our review. These include: possibility of missing out on some of the documents that are not publicly available online and those still in the drafting stages. We also recognize that our findings will be limited to documents that fall within the inclusion criteria.

14. Conclusion: Emphasizes intended use of findings to influence policy. Too generic. Does not outline how findings will be shared, with whom, and for what purpose. Hence, Author should add specifics: “We will share findings with the Kenya EPI taskforce, civil society actors, and Ministry of Health policymakers through workshops and briefings.”
Response: In the revised conclusion, we have specified that we will share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels.

Areas needing revision

15. Conceptual Clarity: Define “vulnerability” more rigorously; use a guiding policy framework (e.g., WHO’s equity lens).
Response: We have provided the following definition of vulnerability in the introduction section

16. Search Strategy: Include a sample string and Google search filtering criteria.
Response: This has been addressed by including a sample search string. We have also indicated that Google searches will be screened for suitability based on their alignment with review objectives and inclusion criteria. We will also only consider documents published by official government institutions and recognized international health organizations.

17. Data Extraction & Coding: Add criteria for identifying implicit mentions; consider coding software.
Response: We have specified the information we intend to extract from the documents and also added the use of NVivo software.

18: Risk of Bias: Discuss selection bias from document inclusion and relevance thresholds.
Response: Under the risk and bias section, we have indicated that potential risks of bias including missing unpublished or documents that are still being drafted and those that fall within the inclusion criteria (only English documents, and those published from 2000-2023).

19. Conclusion: Specify dissemination pathways and intended policy impact more explicitly.
We plan to share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels to contribute to the improvement of the immunization policy landscape in Kenya.
Thank you very much Dr Morufu Olalekan Raimi, for taking the time to review our manuscript. We truly appreciate your valuable and useful feedback and comments. Below, please find our responses to the issues you raised.

Title and abstract
1. The revised title is clearer and better aligned with the focus on Kenya and “vulnerability.” Abstract introduces rationale, methods, and aims adequately. The term “systematic review” remains potentially misleading for policy documents. Though addressed in previous peer reviews, a footnote or clarification on the nature of this “review” (policy document analysis vs. intervention or clinical trial) may still be helpful.
Response: We have added a footnote to clarify that this is a review of policy documents and not published peer-reviewed literature.

2. The sentence “...this has been attributed to several challenges/vulnerability factors” is vague. Use more precise terms (e.g., geographic inequality, socio-economic status, maternal education, etc.). Author should consider “systematic policy review” or “document analysis” as part of the subtitle.

Response: We have included more precise terms (socio-economic, individual and health system vulnerabilities)

3. Add 1-2 key expected outputs (e.g., frameworks, recommendations) in the abstract.

Response: We have indicated that using the review findings, we will formulate recommendations to be shared with health and EPI stakeholders at the national, county and sub-county levels.

Plain English Summary
4: Simplifies technical content for lay readers effectively and gives a clear sense of relevance and practical application. Contains overly long and repetitive sentences.

Response: We have revised the plain English summary to be more precise

Introduction
5. Many sentences are generic and overstate well-known facts (e.g., “Vaccines...prevent disease outbreaks and deaths”). Author should cite specific immunization coverage stats from Kenya to better localize the narrative (e.g., coverage in counties like Turkana vs. Nairobi).

Response: To illustrate the disparities within the country, we have provided the recent vaccine coverage data from the 2022 Kenya Demographic and Health Survey (KHDS).

6. Expand on what “framing” means, define whether it's inclusion, prioritization, or operationalization of vulnerability.
Response: A footnote has been added to expand on what we mean by “framing”. In this protocol, framing refers to how vulnerability is defined and operationalized as well as components considered.

Methods
7. The rationale for focusing solely on English-language documents could be expanded upon given potential inclusion of Kiswahili policy texts.
Response: We have expanded on the rationale of focusing on the English documents, which is because English is the primary language for official government policy documentation, especially for national and county-level strategies, policies and plans in Kenya. In addition, we have included only English policy documents to ensure consistent interpretation of the policy documents.

8. No detail is provided on how the Google searches will be validated for relevance, or how source credibility will be assessed. Author should add a sample search string (already suggested by a previous reviewer) and include a visual flow diagram (e.g., PRISMA-style chart) in the final paper.
Response: To validate Google searches, Google search results will be screened for relevance based on alignment with the study objectives and inclusion criteria. Only documents published by official government institutions and recognized international health organizations will be prioritized. A sample of search search strings will include Vaccin* OR immuniz*) AND Kenya; (routine vaccin* OR routine immuniz*) AND Kenya; (Vaccin* OR immuniz*) AND (vulnerab* OR marginalized) AND Kenya; (routine vaccin* OR routine immuniz*) AND ("Expanded Programme on Immunization" OR EPI OR KEPI).

9. No mention of whether inter-rater reliability or agreement measures (e.g., Cohen’s Kappa) will be used. Author should clarify the criteria for resolving disagreements during screening as well as specify who will perform quality control and ensure consistency.
Response: Whereas we don’t intend to use formal inter-rater reliability measures (e.g., Cohen’s Kappa in this review, the team will hold meetings to discuss the relevance of documents to be included for review and any disagreements addressed during the discussions.

10. The explanation of what constitutes “explicit and implicit” vulnerability-related information is vague. Author should define indicators of implicit vulnerability (e.g., mention of remote populations, nomadic groups, maternal illiteracy) and consider aligning categories with a policy analysis framework such as Walt & Gilson’s policy triangle.
Response: We have spelt out the specific information on vulnerability that we intend to extract. This will be how vulnerability is defined, who is considered vulnerable and strategies to address the needs of those considered vulnerable. As for the use of a policy analysis framework such as Walt & Gilson’s policy triangle, in this review we only plan to synthesise the content of policy documents.

11. The author should mention potential uses of findings (e.g., stakeholder engagement, policy briefs).
Response: We have added information on how we intend to use the findings of the review. Our plan is to share the review findings with stakeholders through policy briefs and dissemination meetings and explore further through primary research focusing on vulnerabilities influencing childhood vaccination in Kenya.

12. No mention of NVivo or qualitative coding software to manage complex themes. Author should consider using software like NVivo or Atlas.ti for theme development and outline how themes will be validated or revised.
Response: We have included use of Nvivo software and the themes will be reviewed and revised through comparison across documents, and any discrepancies will be discussed amongst reviewers until a consensus is reached.

13. Author should add a paragraph in the discussion acknowledging this limitation e.g., exclusion of unpublished or draft policies.
Response: We have outlined the biases we foresee in our review. These include: possibility of missing out on some of the documents that are not publicly available online and those still in the drafting stages. We also recognize that our findings will be limited to documents that fall within the inclusion criteria.

14. Conclusion: Emphasizes intended use of findings to influence policy. Too generic. Does not outline how findings will be shared, with whom, and for what purpose. Hence, Author should add specifics: “We will share findings with the Kenya EPI taskforce, civil society actors, and Ministry of Health policymakers through workshops and briefings.”
Response: In the revised conclusion, we have specified that we will share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels.

Areas needing revision

15. Conceptual Clarity: Define “vulnerability” more rigorously; use a guiding policy framework (e.g., WHO’s equity lens).
Response: We have provided the following definition of vulnerability in the introduction section

16. Search Strategy: Include a sample string and Google search filtering criteria.
Response: This has been addressed by including a sample search string. We have also indicated that Google searches will be screened for suitability based on their alignment with review objectives and inclusion criteria. We will also only consider documents published by official government institutions and recognized international health organizations.

17. Data Extraction & Coding: Add criteria for identifying implicit mentions; consider coding software.
Response: We have specified the information we intend to extract from the documents and also added the use of NVivo software.

18: Risk of Bias: Discuss selection bias from document inclusion and relevance thresholds.
Response: Under the risk and bias section, we have indicated that potential risks of bias including missing unpublished or documents that are still being drafted and those that fall within the inclusion criteria (only English documents, and those published from 2000-2023).

19. Conclusion: Specify dissemination pathways and intended policy impact more explicitly.
We plan to share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels to contribute to the improvement of the immunization policy landscape in Kenya.
Competing Interests: No competing interests were disclosed. Close
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Reviewer Report 30 May 2025

Patricia Mechael, HealthEnabled, Cape Town, South Africa

Approved

https://doi.org/10.3310/nihropenres.15217.r35834

This revision is much improved. The authors have sufficiently addressed the ... Continue reading

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Version 1

VERSION 1

PUBLISHED 24 Nov 2023

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Reviewer Report 11 May 2024

Nicholas Spencer, University of Warwick, Coventry, England, UK

Approved with Reservations

https://doi.org/10.3310/nihropenres.14588.r31141

As the authors state, equity in vaccination uptake and coverage is essential in achieving the targets of the WHO agenda 2021-2030. The proposed review aims to explore the extent to which issues of (in)equity are included in Kenyan and Ugandan policy documents and identify gaps and opportunities presumably with a view to informing strategies to promote equity. I assume that the authors are aware of existing inequity in the two countries and relevant existing data should be included in the introduction to give the reader an indication of the extent of the problem.
Methodology used in conducting a systematic reviews of policy documents may differ in some respects from that required for a systematic review of published literature but clear inclusion/exclusion criteria and an appropriate measure of quality of the document would seem to me to be essential components of a robust review. The policy analysis triangle may provide a measure of quality but the authors need to specify how they will assess quality.
This is a potentially valuable contribution to addressing vaccination inequity in these two countries but I think attention should be given to the issues I have raised.

Is the rationale for, and objectives of, the study clearly described?

Yes
Is the study design appropriate for the research question?

Partly
Are sufficient details of the methods provided to allow replication by others?

Partly
Are the datasets clearly presented in a useable and accessible format?

Not applicable

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Inequity in child health; Child Public Health including vaccination coverage issues

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Author Response 10 Mar 2026

Esther Owino, Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya

10 Mar 2026

Author Response

Thank you very much for the useful feedback.
We have added the Inclusion criteria in the revised protocol.
About the quality of the documents, we only aimed to examine the ... Continue reading Thank you very much for the useful feedback.
We have added the Inclusion criteria in the revised protocol.
About the quality of the documents, we only aimed to examine the content of the documents in regard to vulnerability since the documents were not vulnerability-specific.
Thank you very much for the useful feedback.
We have added the Inclusion criteria in the revised protocol.
About the quality of the documents, we only aimed to examine the content of the documents in regard to vulnerability since the documents were not vulnerability-specific.
Competing Interests: None Close
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COMMENTS ON THIS REPORT

Author Response 10 Mar 2026

Esther Owino, Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya

10 Mar 2026

Author Response

Thank you very much for the useful feedback.
We have added the Inclusion criteria in the revised protocol.
About the quality of the documents, we only aimed to examine the ... Continue reading Thank you very much for the useful feedback.
We have added the Inclusion criteria in the revised protocol.
About the quality of the documents, we only aimed to examine the content of the documents in regard to vulnerability since the documents were not vulnerability-specific.
Thank you very much for the useful feedback.
We have added the Inclusion criteria in the revised protocol.
About the quality of the documents, we only aimed to examine the content of the documents in regard to vulnerability since the documents were not vulnerability-specific.
Competing Interests: None Close
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Reviewer Report 11 May 2024

Patricia Mechael, HealthEnabled, Cape Town, South Africa

Approved with Reservations

https://doi.org/10.3310/nihropenres.14588.r31362

This proposed review of equity policies related to immunization is an important and timely piece of work. One recommendation is to not call it a "systematic review" as that has connotations of a state of evidence review based on randomized controlled trials. Rather it could be referred to as a "systematic policy review" or "systematic review of policies."

A few additions that would strengthen the protocol would be the inclusion of a search strategy and/or initial coding structure, a proposed output of a timeline mapping number and type of equity-focused policies, and a proposed output of summarizing an equity-related immunization outcome (such as number/percent of zero-dose children) as available in existing surveys such as Demographic and Health Surveys and/or MICS.

Is the rationale for, and objectives of, the study clearly described?

Yes
Is the study design appropriate for the research question?

Yes
Are sufficient details of the methods provided to allow replication by others?

Partly
Are the datasets clearly presented in a useable and accessible format?

Partly

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Immunization, digital health, data use, health equity

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Author Response 28 May 2025

Esther Owino, Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya

28 May 2025

Author Response

Thank you very much for this useful feedback.
We have incorporated the recommendation about the title. The revised title now reads as follows; Vulnerability and childhood immunization in Kenya: a systematic review ... Continue reading Thank you very much for this useful feedback.
We have incorporated the recommendation about the title. The revised title now reads as follows; Vulnerability and childhood immunization in Kenya: a systematic review of policy documents protocol

We have included the Inclusion and search strategy in the revised version.
We have also included a data extraction template as one of our extended data files.

Since we have revised the scope of the protocol and the focus is no longer on equity but vulnerability, the recommendation to map equity-based policies might not be applicable.
Thank you very much for this useful feedback.
We have incorporated the recommendation about the title. The revised title now reads as follows; Vulnerability and childhood immunization in Kenya: a systematic review of policy documents protocol

We have included the Inclusion and search strategy in the revised version.
We have also included a data extraction template as one of our extended data files.

Since we have revised the scope of the protocol and the focus is no longer on equity but vulnerability, the recommendation to map equity-based policies might not be applicable.
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Author Response 28 May 2025

Esther Owino, Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya

28 May 2025

Author Response

Thank you very much for this useful feedback.
We have incorporated the recommendation about the title. The revised title now reads as follows; Vulnerability and childhood immunization in Kenya: a systematic review ... Continue reading Thank you very much for this useful feedback.
We have incorporated the recommendation about the title. The revised title now reads as follows; Vulnerability and childhood immunization in Kenya: a systematic review of policy documents protocol

We have included the Inclusion and search strategy in the revised version.
We have also included a data extraction template as one of our extended data files.

Since we have revised the scope of the protocol and the focus is no longer on equity but vulnerability, the recommendation to map equity-based policies might not be applicable.
Thank you very much for this useful feedback.
We have incorporated the recommendation about the title. The revised title now reads as follows; Vulnerability and childhood immunization in Kenya: a systematic review of policy documents protocol

We have included the Inclusion and search strategy in the revised version.
We have also included a data extraction template as one of our extended data files.

Since we have revised the scope of the protocol and the focus is no longer on equity but vulnerability, the recommendation to map equity-based policies might not be applicable.
Competing Interests: None Close
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Version 3

VERSION 3 PUBLISHED 24 Nov 2023

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	Invited Reviewers
	1	2	3
Version 3 (revision) 10 Mar 26		read
Version 2 (revision) 27 May 25	read		read
Version 1 24 Nov 23	read	read

Patricia Mechael, HealthEnabled, Cape Town, South Africa
Nicholas Spencer, University of Warwick, Coventry, UK
Morufu Olalekan Raimi, Federal University Otuoke, Otuoke, Nigeria

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Reviewer Report

1 Views

12 Mar 2026 | for Version 3

Nicholas Spencer, University of Warwick, Coventry, England, UK

1 Views Cite this report Responses(0)

Approved

The authors have revised the paper in line with my suggestions and those of other reviewers. I am satisfied that the revisions have improved the protocol.

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Equity research

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

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Reviewer Report

14 Views

04 Nov 2025 | for Version 2

Morufu Olalekan Raimi, Federal University Otuoke, Otuoke, Nigeria

14 Views Cite this report Responses(1)

Approved With Reservations

Insufficient methodological detail for full replication,
A lack of conceptual clarity around “vulnerability,”
Overuse of generic phrasing without sufficient policy analysis theory grounding,
Structural inconsistencies (e.g., ambiguous timelines, redundancy in explanation).

This review presents detailed paragraph-level feedback, followed by overall recommendations.

B. DETAILED SECTION-BY-SECTION REVIEW

1. Title and Abstract

The revised title is clearer and better aligned with the focus on Kenya and “vulnerability.” Abstract introduces rationale, methods, and aims adequately.

The term “systematic review” remains potentially misleading for policy documents. Though addressed in previous peer reviews, a footnote or clarification on the nature of this “review” (policy document analysis vs. intervention or clinical trial) may still be helpful.
The sentence “...this has been attributed to several challenges/vulnerability factors” is vague. Use more precise terms (e.g., geographic inequality, socio-economic status, maternal education, etc.). Author should consider “systematic policy review” or “document analysis” as part of the subtitle.

Add 1-2 key expected outputs (e.g., frameworks, recommendations) in the abstract.

2. Plain English Summary

Simplifies technical content for lay readers effectively and gives a clear sense of relevance and practical application. Contains overly long and repetitive sentences.

The last paragraph restates the same information from the abstract almost verbatim. Example: “...examine how this is working out at country level...whether this is captured in their policy documents.” This can be shortened and rephrased for clarity. Author should trim redundancy; group benefits, equity aims, and method into clearer subsections as well as add clarity on the population of interest (e.g., age ranges, vulnerable groups).

3. Introduction

Strong justification for immunization as a public health strategy and use of global data and WHO sources improves credibility. Many sentences are generic and overstate well-known facts (e.g., “Vaccines...prevent disease outbreaks and deaths”). Author should cite specific immunization coverage stats from Kenya to better localize the narrative (e.g., coverage in counties like Turkana vs. Nairobi).

Cites previous reviews and identifies literature gaps effectively. The claim: “how these vulnerability issues are framed...in grey literature...is lacking” is weak without citing national health policies or strategies reviewed in prior studies. Author should cite at least 1-2 key documents (e.g., Kenya Health Policy 2014–2030) to support this gap. Expand on what “framing” means, define whether it's inclusion, prioritization, or operationalization of vulnerability.

4. Methods
Inclusion Criteria:

Temporal scope (2000–2023) is justified and aligns with GAVI-era reforms and language and type of documents are clearly listed. The rationale for focusing solely on English-language documents could be expanded upon given potential inclusion of Kiswahili policy texts.

Information Sources & Search Strategy:

Multiple source types are considered, from MOH websites to gray literature and personal contacts. No detail is provided on how the Google searches will be validated for relevance, or how source credibility will be assessed. Author should add a sample search string (already suggested by a previous reviewer) and include a visual flow diagram (e.g., PRISMA-style chart) in the final paper.

Study Records, Data Management & Selection:

Use of EndNote/Mendeley and consensus screening is appropriate. No mention of whether inter-rater reliability or agreement measures (e.g., Cohen’s Kappa) will be used. Author should clarify the criteria for resolving disagreements during screening as well as specify who will perform quality control and ensure consistency.

Data Collection and Extraction:

Inclusion of a data extraction template is commendable and enhances transparency.

The explanation of what constitutes “explicit and implicit” vulnerability-related information is vague. Author should define indicators of implicit vulnerability (e.g., mention of remote populations, nomadic groups, maternal illiteracy) and consider aligning categories with a policy analysis framework such as Walt & Gilson’s policy triangle.

Review Outcomes:

Clearly articulated: framing, strategies, gaps, and opportunities. “Gaps and opportunities” are vague without examples of potential policy levers (e.g., funding, service delivery). Author should mention potential uses of findings (e.g., stakeholder engagement, policy briefs).

5. Data Synthesis

Inductive thematic analysis is appropriate for qualitative document review. No mention of NVivo or qualitative coding software to manage complex themes. Author should consider using software like NVivo or Atlas.ti for theme development and outline how themes will be validated or revised.

6. Ethics & Bias Consideration

Noted as “Not applicable” for risk of bias/meta-bias. While true for empirical bias, the risk of selection bias in policy document inclusion exists and is not addressed. Author should add a paragraph in the discussion acknowledging this limitation e.g., exclusion of unpublished or draft policies.

7. Conclusion

Emphasizes intended use of findings to influence policy. Too generic. Does not outline how findings will be shared, with whom, and for what purpose. Hence, Author should add specifics: “We will share findings with the Kenya EPI taskforce, civil society actors, and Ministry of Health policymakers through workshops and briefings.”

8. Extended Data & Reporting

Inclusion of PRISMA-P and a data extraction template shows protocol rigor. Author should ensure that the final publication also includes:

PRISMA flow diagram.
A sample of coded policy excerpts in supplementary material.

C. OVERALL STRENGTHS

Responds well to previous reviews and narrows its scope effectively.
Clearly structured protocol with transparent data collection and extraction plans.
Solid foundation for future primary research on immunization access in Kenya.

Is the rationale for, and objectives of, the study clearly described?

Yes
Is the study design appropriate for the research question?

Yes
Are sufficient details of the methods provided to allow replication by others?

Yes
Are the datasets clearly presented in a useable and accessible format?

Yes

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Environmental Epidemiology; Climate Change and Health; Pollution Control Management; Public Health; Groundwater Quality

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Author Response

10 Mar 2026

Esther Owino, Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya

Thank you very much Dr Morufu Olalekan Raimi, for taking the time to review our manuscript. We truly appreciate your valuable and useful feedback and comments. Below, please find our responses to the issues you raised.

Title and abstract
1. The revised title is clearer and better aligned with the focus on Kenya and “vulnerability.” Abstract introduces rationale, methods, and aims adequately. The term “systematic review” remains potentially misleading for policy documents. Though addressed in previous peer reviews, a footnote or clarification on the nature of this “review” (policy document analysis vs. intervention or clinical trial) may still be helpful.
Response: We have added a footnote to clarify that this is a review of policy documents and not published peer-reviewed literature.

2. The sentence “...this has been attributed to several challenges/vulnerability factors” is vague. Use more precise terms (e.g., geographic inequality, socio-economic status, maternal education, etc.). Author should consider “systematic policy review” or “document analysis” as part of the subtitle.

Response: We have included more precise terms (socio-economic, individual and health system vulnerabilities)

3. Add 1-2 key expected outputs (e.g., frameworks, recommendations) in the abstract.

Response: We have indicated that using the review findings, we will formulate recommendations to be shared with health and EPI stakeholders at the national, county and sub-county levels.

Plain English Summary
4: Simplifies technical content for lay readers effectively and gives a clear sense of relevance and practical application. Contains overly long and repetitive sentences.

Response: We have revised the plain English summary to be more precise

Introduction
5. Many sentences are generic and overstate well-known facts (e.g., “Vaccines...prevent disease outbreaks and deaths”). Author should cite specific immunization coverage stats from Kenya to better localize the narrative (e.g., coverage in counties like Turkana vs. Nairobi).

Response: To illustrate the disparities within the country, we have provided the recent vaccine coverage data from the 2022 Kenya Demographic and Health Survey (KHDS).

6. Expand on what “framing” means, define whether it's inclusion, prioritization, or operationalization of vulnerability.
Response: A footnote has been added to expand on what we mean by “framing”. In this protocol, framing refers to how vulnerability is defined and operationalized as well as components considered.

Methods
7. The rationale for focusing solely on English-language documents could be expanded upon given potential inclusion of Kiswahili policy texts.
Response: We have expanded on the rationale of focusing on the English documents, which is because English is the primary language for official government policy documentation, especially for national and county-level strategies, policies and plans in Kenya. In addition, we have included only English policy documents to ensure consistent interpretation of the policy documents.

8. No detail is provided on how the Google searches will be validated for relevance, or how source credibility will be assessed. Author should add a sample search string (already suggested by a previous reviewer) and include a visual flow diagram (e.g., PRISMA-style chart) in the final paper.
Response: To validate Google searches, Google search results will be screened for relevance based on alignment with the study objectives and inclusion criteria. Only documents published by official government institutions and recognized international health organizations will be prioritized. A sample of search search strings will include Vaccin* OR immuniz*) AND Kenya; (routine vaccin* OR routine immuniz*) AND Kenya; (Vaccin* OR immuniz*) AND (vulnerab* OR marginalized) AND Kenya; (routine vaccin* OR routine immuniz*) AND ("Expanded Programme on Immunization" OR EPI OR KEPI).

9. No mention of whether inter-rater reliability or agreement measures (e.g., Cohen’s Kappa) will be used. Author should clarify the criteria for resolving disagreements during screening as well as specify who will perform quality control and ensure consistency.
Response: Whereas we don’t intend to use formal inter-rater reliability measures (e.g., Cohen’s Kappa in this review, the team will hold meetings to discuss the relevance of documents to be included for review and any disagreements addressed during the discussions.

10. The explanation of what constitutes “explicit and implicit” vulnerability-related information is vague. Author should define indicators of implicit vulnerability (e.g., mention of remote populations, nomadic groups, maternal illiteracy) and consider aligning categories with a policy analysis framework such as Walt & Gilson’s policy triangle.
Response: We have spelt out the specific information on vulnerability that we intend to extract. This will be how vulnerability is defined, who is considered vulnerable and strategies to address the needs of those considered vulnerable. As for the use of a policy analysis framework such as Walt & Gilson’s policy triangle, in this review we only plan to synthesise the content of policy documents.

11. The author should mention potential uses of findings (e.g., stakeholder engagement, policy briefs).
Response: We have added information on how we intend to use the findings of the review. Our plan is to share the review findings with stakeholders through policy briefs and dissemination meetings and explore further through primary research focusing on vulnerabilities influencing childhood vaccination in Kenya.

12. No mention of NVivo or qualitative coding software to manage complex themes. Author should consider using software like NVivo or Atlas.ti for theme development and outline how themes will be validated or revised.
Response: We have included use of Nvivo software and the themes will be reviewed and revised through comparison across documents, and any discrepancies will be discussed amongst reviewers until a consensus is reached.

13. Author should add a paragraph in the discussion acknowledging this limitation e.g., exclusion of unpublished or draft policies.
Response: We have outlined the biases we foresee in our review. These include: possibility of missing out on some of the documents that are not publicly available online and those still in the drafting stages. We also recognize that our findings will be limited to documents that fall within the inclusion criteria.

14. Conclusion: Emphasizes intended use of findings to influence policy. Too generic. Does not outline how findings will be shared, with whom, and for what purpose. Hence, Author should add specifics: “We will share findings with the Kenya EPI taskforce, civil society actors, and Ministry of Health policymakers through workshops and briefings.”
Response: In the revised conclusion, we have specified that we will share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels.

Areas needing revision

15. Conceptual Clarity: Define “vulnerability” more rigorously; use a guiding policy framework (e.g., WHO’s equity lens).
Response: We have provided the following definition of vulnerability in the introduction section

16. Search Strategy: Include a sample string and Google search filtering criteria.
Response: This has been addressed by including a sample search string. We have also indicated that Google searches will be screened for suitability based on their alignment with review objectives and inclusion criteria. We will also only consider documents published by official government institutions and recognized international health organizations.

17. Data Extraction & Coding: Add criteria for identifying implicit mentions; consider coding software.
Response: We have specified the information we intend to extract from the documents and also added the use of NVivo software.

18: Risk of Bias: Discuss selection bias from document inclusion and relevance thresholds.
Response: Under the risk and bias section, we have indicated that potential risks of bias including missing unpublished or documents that are still being drafted and those that fall within the inclusion criteria (only English documents, and those published from 2000-2023).

19. Conclusion: Specify dissemination pathways and intended policy impact more explicitly.
We plan to share the findings through policy briefs and dissemination meetings with health and EPI stakeholders at national, county and sub-county levels to contribute to the improvement of the immunization policy landscape in Kenya.

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Competing Interests

No competing interests were disclosed.

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Reviewer Report

11 Views

30 May 2025 | for Version 2

Patricia Mechael, HealthEnabled, Cape Town, South Africa

11 Views Cite this report Responses(0)

Approved

This revision is much improved. The authors have sufficiently addressed the reviewer comments provided. I look forward to reading the study findings.

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Immunization, digital health, data use, health equity

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

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Reviewer Report

16 Views

11 May 2024 | for Version 1

Nicholas Spencer, University of Warwick, Coventry, England, UK

16 Views Cite this report Responses(1)

Approved With Reservations

Is the rationale for, and objectives of, the study clearly described?

Yes
Is the study design appropriate for the research question?

Partly
Are sufficient details of the methods provided to allow replication by others?

Partly
Are the datasets clearly presented in a useable and accessible format?

Not applicable

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Inequity in child health; Child Public Health including vaccination coverage issues

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Reviewer Report

15 Views

11 May 2024 | for Version 1

Patricia Mechael, HealthEnabled, Cape Town, South Africa

15 Views Cite this report Responses(1)

Approved With Reservations

Is the rationale for, and objectives of, the study clearly described?

Yes
Is the study design appropriate for the research question?

Yes
Are sufficient details of the methods provided to allow replication by others?

Partly
Are the datasets clearly presented in a useable and accessible format?

Partly

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Immunization, digital health, data use, health equity

Respond to this report

Responses (1)

Author Response

28 May 2025

Esther Owino, Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya

Thank you very much for this useful feedback.
We have incorporated the recommendation about the title. The revised title now reads as follows; Vulnerability and childhood immunization in Kenya: a systematic review of policy documents protocol

We have included the Inclusion and search strategy in the revised version.
We have also included a data extraction template as one of our extended data files.

Since we have revised the scope of the protocol and the focus is no longer on equity but vulnerability, the recommendation to map equity-based policies might not be applicable.

View more View less

Competing Interests

None

Alongside their report, reviewers assign a status to the article:

Approved - the paper is scientifically sound in its current form and only minor, if any, improvements are suggested

Approved with reservations - A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit.

Not approved - fundamental flaws in the paper seriously undermine the findings and conclusions

[1] 1. Doughty HC, Hill RA, Riley A, et al.: Barriers to and facilitators of physical activity in adults living with and beyond cancer, with special emphasis on head and neck cancer: a systematic review of qualitative and mixed methods studies. Support Care Cancer. 2023; 31(8): 471. PubMed Abstract | Publisher Full Text

[2] 2. World Health Organzation (WHO): Explorations of inequality: Childhood immunization. 2018.

[3] 3. Rodrigues CMC, Plotkin SA: Impact of Vaccines; Health, Economic and Social Perspectives. Front Microbiol. 2020; 11: 1526. Publisher Full Text

[4] 4. World Health Organization (WHO): Regional Strategic Plan for Immunization 2014–2020. 2015.

[5] 5. Kaur G, et al. Routine Vaccination Coverage — Worldwide, 2022. 2023 [cited 2024 Feb 20, 2024]. https://www.cdc.gov/mmwr/volumes/72/wr/mm7243a1.htm

[6] 6. Ikilezi G, Augusto OJ, Sbarra A, et al.: Determinants of geographical inequalities for DTP3 vaccine coverage in sub-Saharan Africa. Vaccine. 2020; 38(18): 3447–3454. PubMed Abstract | Publisher Full Text

[7] 7. Kenya National Bureau of Statistics (KNBS):Kenya Demographic and Health Survey 2022. 2023.

[8] 8. Grabovschi C, Loignon C, Fortin M: Mapping the concept of vulnerability related to health care disparities: A scoping review. BMC Health Serv Res. 2013; 13(94).

[9] 9. Bangura JB, Xiao S, Qiu D, et al.: Barriers to childhood immunization in sub-Saharan Africa: A systematic review. BMC Public Health. 2020; 20(1): 1108. PubMed Abstract | Publisher Full Text | Free Full Text

[10] 10. Galadima AN, Zulkefli NAM, Said SM, et al.: Factors influencing childhood immunisation uptake in Africa: a systematic review. BMC Public Health. 2021; 21(1): 1475. PubMed Abstract | Publisher Full Text | Free Full Text

[11] 11. Allan S, Adetifa IMO, Abbas K: Inequities in childhood immunisation coverage associated with socioeconomic, geographic, maternal, child, and place of birth characteristics in Kenya. BMC Infect Dis. 2021; 21(1): 553. PubMed Abstract | Publisher Full Text | Free Full Text

[12] 12. Mutua MK, et al.: Fully immunized child: coverage, timing and sequencing of routine immunization in an urban poor settlement in Nairobi, Kenya. Trop Med Health. 2016; 44(13).

[13] 13. Owino E, Mafigiri D, Kamuya D, et al.: Equity, vulnerability and childhood immunization in Kenya and Uganda. A review of policy documents protocol. NIHR Open Res. 2023; 3. Publisher Full Text

Vulnerability and childhood immunization in Kenya. A systematic review of policy documents protocol.

Abstract

Abstract

Plain Language Summary

Plain English Summary

Keywords

Revised Amendments from Version 2

Introduction

Methods

Inclusion criteria

Information sources

Search strategy

Study records

Review outcomes

Risk of bias in individual studies

Data synthesis

Meta-bias(es)

Confidence in cumulative evidence

Study status

Conclusion

Data availability

Extended data

Reporting guidelines

References

Footnotes

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Vulnerability and childhood immunization in Kenya. A systematic review of policy documents protocol.

Abstract

Abstract

Plain Language Summary

Plain English Summary

Keywords

Revised Amendments from Version 2

Introduction

Methods

Inclusion criteria

Information sources

Search strategy

Study records

Review outcomes

Risk of bias in individual studies

Data synthesis

Meta-bias(es)

Confidence in cumulative evidence

Study status

Conclusion

Data availability

Extended data

Reporting guidelines

References

Footnotes

Comments on this article Comments (0)

Open Peer Review

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Open Peer Review

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Reviewer Reports

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