Prevalence, spatial patterns and determinants of zero-dose vaccination among children aged 12–23 months in Sub-Saharan Africa: A multilevel spatial analysis

Tadesse Tarik Tamir; Muluken Chanie Agimas; Dessie Abebaw Angaw

doi:10.1371/journal.pone.0344293

Peer Review History

Original SubmissionJuly 17, 2025
6 Jan 2026 Decision Letter - Edison Mworozi, Editor Dear Dr. Tamir, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Feb 20 2026 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. A letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. 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Please kindly revise as necessary and re-upload. Additional Editor Comments: Please address comments by reviewer one and ensure to resubmit a proper evidence backed paper in a lucid manner. Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? Reviewer #1: Yes Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? -->?> Reviewer #1: Yes Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available??> The PLOS Data policy Reviewer #1: Yes Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English??> Reviewer #1: Yes Reviewer #2: Yes ****** Reviewer #1: The purpose of this study is to conduct a mathematical analysis of the prevalence, spatial distribution, and determinants of zero-dose vaccination among children aged 12 to 23 months in sub-Saharan Africa applying a spatial multilevel modeling approach, thereby informing more targeted and effective immunization strategies. However, this analysis involves the use of complex mathematical models to investigate factors that have already been described before the current work using simpler methods. Moreover, in the discussion, the authors point out that the results they obtained are similar to the results obtained before this work. In the process of reading the materials of the article, a clinician may have difficulties interpreting and perceiving the presented material. In this regard, this scientific work is more suitable for specialists in the field of statistics, since it contains a large number of specific terms and approaches. It is necessary to shorten the description of the methods used and provide links to relevant works in which these approaches are described in detail. The Introduction section does not indicate the advantage of the analysis method used, which would distinguish it from other informative methods. This may reduce the reader's interest in new data and results. The results of the study are well described, but the section also needs to be shortened. The Discussion section notes that the study revealed the prevalence, spatial variation, and individual- & community-level factors of zero-dose vaccination among children aged 12-23 months in sub-Saharan Africa using data from the 2015 to 2024 DHS with the application of a multilevel spatial model which accounts for the hierarchical nature of the data with its spatial dimension. However, it is further indicated that the obtained prevalence is consistent with the data previously reported in the systematic review of 204 countries: this indicator was almost the same, and the prevalence of zero-dose use ranged from 13.4% to 15.9%. A similar situation is observed for other results obtained for other factors under study. In this regard, the question arises about the expediency of conducting research and writing material. During the study, no new data was obtained or previously unknown factors and patterns were identified. In this regard, if new conclusions have been drawn in the course of the work, the authors should present them in a clearer form, comparing them with the results of other similar studies and demonstrating the advantages of the analysis method used. Otherwise, there is a risk that any statistical analysis method can be used to interpret data that is already known. The material of the article seems to be voluminous and difficult to understand, therefore, in my opinion, it requires revision and reduction. However, it is worth noting that the manuscript ends with recommendations for international and national authorities, as well as stakeholders, that can help minimize the number of zero-dose vaccinated children aged 12 to 23 months in sub-Saharan Africa. Reviewer #2: The methodology is well explained, the discussion part is well elaborated and results explicitly identify the gaps which can be covered by the respective immunization programmes factoring in the hot spots ****** what does this mean? ). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? 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Attachments Attachment Submitted filename: PONE-D-25-38190.pdf https://doi.org/10.1371/journal.pone.0344293.r001
Revision 1
21 Jan 2026 Author Response Subject: Submission of revised manuscript Manuscript ID: [PONE-D-25-38190] - [EMID:8abf81ed5e5104bf] Title: Prevalence, Spatial Patterns and Determinants of Zero-Dose Vaccination among Children Aged 12-23 Months in Sub-Saharan Africa: A Multilevel Spatial Analysis Journal: PLOS One I hope this letter finds you well. We appreciate the diligent efforts of the editorial team in facilitating the review process for our manuscript. Additionally, we extend our gratitude to the editors and reviewers for their valuable time and thoughtful feedback, which significantly contributed to enhancing the quality of our work. The constructive comments provided by the reviewers have been instrumental in refining our study. We are pleased to note that the reviewers share our assessment of the scientific significance of our findings. In response to their suggestions, we have meticulously addressed each point raised. Please find our comprehensive responses to the comments below. Furthermore, I have attached the revised manuscript file separately for your convenience. We believe that the revisions strengthen the manuscript and align it more closely with the journal’s scope and standards. Thank you for considering our work for publication. We hope that our revised submission meets the high standards set by PLOS One. Best regards, Corresponding Author Response to comments Reviewer #1: The purpose of this study is to conduct a mathematical analysis of the prevalence, spatial distribution, and determinants of zero-dose vaccination among children aged 12 to 23 months in sub-Saharan Africa applying a spatial multilevel modeling approach, thereby informing more targeted and effective immunization strategies. However, this analysis involves the use of complex mathematical models to investigate factors that have already been described before the current work using simpler methods. Moreover, in the discussion, the authors point out that the results they obtained are similar to the results obtained before this work. In the process of reading the materials of the article, a clinician may have difficulties interpreting and perceiving the presented material. In this regard, this scientific work is more suitable for specialists in the field of statistics, since it contains a large number of specific terms and approaches. It is necessary to shorten the description of the methods used and provide links to relevant works in which these approaches are described in detail. Response: Dear Reviewer, thank you for your thoughtful and detailed feedback. We appreciate your observation regarding the complexity of the methods section. Our initial intention was to provide sufficient detail to ensure transparency and reproducibility of the analysis. However, we fully understand your concern and have revised the manuscript accordingly. Specifically, we have shortened the methods section in the main text and moved the detailed analytical procedures to a supplementary file. Additionally, we have included references to relevant works that describe these approaches in detail. We hope these changes address your concern and make the manuscript more accessible to a broader audience. The Introduction section does not indicate the advantage of the analysis method used, which would distinguish it from other informative methods. This may reduce the reader's interest in new data and results. Response: Thank you for highlighting this important point. We have substantially revised the introduction to clearly articulate the advantages of the spatial multilevel modeling approach and how it adds value beyond previous studies. The revised section emphasizes the novelty of incorporating spatial dimensions and hierarchical structures, which allows for more precise identification of geographic disparities and contextual factors influencing zero-dose vaccination. We believe this revision strengthens the rationale for our methodological choice. The results of the study are well described, but the section also needs to be shortened. Response: We appreciate your suggestion. In response, we have carefully revised and condensed the results section while retaining all essential findings. We believe the revised version is more concise and easier to follow. Please refer to the updated manuscript for these changes. The Discussion section notes that the study revealed the prevalence, spatial variation, and individual- & community-level factors of zero-dose vaccination among children aged 12-23 months in sub-Saharan Africa using data from the 2015 to 2024 DHS with the application of a multilevel spatial model which accounts for the hierarchical nature of the data with its spatial dimension. However, it is further indicated that the obtained prevalence is consistent with the data previously reported in the systematic review of 204 countries: this indicator was almost the same, and the prevalence of zero-dose use ranged from 13.4% to 15.9%. Response: Thank you for your constructive observation. While our pooled prevalence estimates are consistent with global systematic review findings, our study provides updated evidence specific to sub-Saharan Africa and highlights significant country-level variations. Several countries exhibit prevalence rates far above the global pooled estimate, which underscores persistent inequities in immunization coverage. This updated regional and country-specific evidence is critical for targeted interventions. We have clarified these points in the discussion to better demonstrate the added value of our analysis. A similar situation is observed for other results obtained for other factors under study. In this regard, the question arises about the expediency of conducting research and writing material. During the study, no new data was obtained or previously unknown factors and patterns were identified. In this regard, if new conclusions have been drawn in the course of the work, the authors should present them in a clearer form, comparing them with the results of other similar studies and demonstrating the advantages of the analysis method used. Otherwise, there is a risk that any statistical analysis method can be used to interpret data that is already known. Response: Thank you for raising this important concern. While many associations align with previous findings, our study provides new insights through advanced modeling. For instance, factors previously reported as significant (e.g., multiple wealth quintiles) were not significant in our analysis, and the strength of associations differed. Specifically, only the poorest wealth quintile remained significant, which contrasts with earlier studies. These nuanced findings, along with spatial clustering patterns, demonstrate the added value of our approach. We have revised the discussion to clearly highlight these new insights and compare them with prior studies. The material of the article seems to be voluminous and difficult to understand, therefore, in my opinion, it requires revision and reduction. Response: We appreciate your feedback and have made several revisions to improve clarity and reduce length. The methods and results sections have been streamlined, and detailed technical content has been moved to supplementary materials. We hope these changes make the manuscript more concise and reader-friendly. However, it is worth noting that the manuscript ends with recommendations for international and national authorities, as well as stakeholders, that can help minimize the number of zero-dose vaccinated children aged 12 to 23 months in sub-Saharan Africa. Reponse: Thank you for acknowledging the practical implications of our study. We appreciate your recognition of the recommendations provided and hope they contribute to actionable strategies for improving immunization coverage. Reviewer #2: The methodology is well explained, the discussion part is well elaborated and results explicitly identify the gaps which can be covered by the respective immunization programmes factoring in the hot spots. Response: Dear Reviewer, thank you for your positive assessment of our manuscript. We are pleased that you found the methodology, discussion, and identification of gaps to be clear and useful. Your encouraging feedback is greatly appreciated. Attachments Attachment Submitted filename: Rebuttal letter.docx https://doi.org/10.1371/journal.pone.0344293.r002
19 Feb 2026 Decision Letter - Edison Mworozi, Editor Prevalence, Spatial Patterns and Determinants of Zero-Dose Vaccination among Children Aged 12-23 Months in Sub-Saharan Africa: A Multilevel Spatial Analysis PONE-D-25-38190R1 Dear authors, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager® and clicking the ‘Update My Information' link at the top of the page. For questions related to billing, please contact billing support . If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Edison Arwanire Mworozi, M.D Academic Editor PLOS One Additional Editor Comments (optional): The paper is wonderful and ready to publish as per the reviewers comments! Reviewers' comments: Reviewer's Responses to Questions Comments to the Author Reviewer #1: All comments have been addressed Reviewer #2: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions??> Reviewer #1: Yes Reviewer #2: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? -->?> Reviewer #1: Yes Reviewer #2: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available??> The PLOS Data policy Reviewer #1: Yes Reviewer #2: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English??> Reviewer #1: Yes Reviewer #2: Yes ****** Reviewer #1: The authors have taken into account all the previous comments and suggestions I made. There are no new comments, so I recommend the manuscript for publication. Reviewer #2: The questions and comments of reviewers on previous iteration have been addressed to maximum extent. ****** what does this mean? ). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy Reviewer #1: Yes: Mikhail P. Kostinov Reviewer #2: Yes: Soofia Yunus ******** https://doi.org/10.1371/journal.pone.0344293.r003
Formally Accepted
Acceptance Letter - Edison Mworozi, Editor PONE-D-25-38190R1 PLOS One Dear Dr. Tamir, I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS One. Congratulations! Your manuscript is now being handed over to our production team. At this stage, our production department will prepare your paper for publication. This includes ensuring the following: * All references, tables, and figures are properly cited * All relevant supporting information is included in the manuscript submission, * There are no issues that prevent the paper from being properly typeset You will receive further instructions from the production team, including instructions on how to review your proof when it is ready. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few days to review your paper and let you know the next and final steps. Lastly, if your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. You will receive an invoice from PLOS for your publication fee after your manuscript has reached the completed accept phase. If you receive an email requesting payment before acceptance or for any other service, this may be a phishing scheme. Learn how to identify phishing emails and protect your accounts at https://explore.plos.org/phishing. If we can help with anything else, please email us at customercare@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Professor Edison Arwanire Mworozi Academic Editor PLOS One https://doi.org/10.1371/journal.pone.0344293.r004

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