Impact of the COVID-19 pandemic on the routine immunization system in Bangladesh

Md. Tanvir Hossen; Md Sayik Bin Alam; Md. Sahidul Islam; Emanuele Montomoli; Ralf Clemens; Sue Ann Costa Clemens; Mohammad Delwer Hossain Hawlader; Md Foyjul Islam

doi:10.1371/journal.pone.0334503

Peer Review History

Original SubmissionJune 3, 2025
18 Jun 2025 Decision Letter - Vanya Rangelova, Editor PONE-D-25-30097Impact of the COVID-19 pandemic on the routine immunization system in BangladeshPLOS ONE Dear Dr. Islam, 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 Aug 02 2025 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. Please include the following items when submitting your revised manuscript: A rebuttal 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'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. 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Reviewer #1: Yes Reviewer #2: No ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: It is an exciting article to publish. The title is Impact of the COVID-19 pandemic on the routine immunization system in Bangladesh, and the ID number is (PONE-D-25-30097). The authors should review the manuscript using Grammarly, as there is still a need to verify spelling and grammar before publishing the article. Reviewer #2: Clarify Methodological Details Provide a more detailed description of the sampling method, inclusion/exclusion criteria, and study design. Define how key variables (e.g., exposure, outcome, covariates) were measured or derived. Improve Statistical Rigor Include measures of variability and significance (e.g., CIs, p-values) consistently. Consider adding multivariable regression models to adjust for potential confounders. Contextualize Findings The Discussion section should be expanded to situate your findings within the context of existing literature. Avoid overgeneralizing your conclusions, especially when causal inference is not supported by study design. Revise Figures and Tables Ensure all tables and figures are self-contained, clearly labeled, and referenced appropriately in the text. Some legends require clarification (e.g., define abbreviations, note sample sizes). ****** 6. PLOS authors have the option to publish the peer review history of their article (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: No Reviewer #2: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org . Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0334503.r001
Revision 1
23 Jun 2025 Author Response Response to Reviewers Manuscript ID: PONE-D-25-30097 Title: Impact of the COVID-19 Pandemic on the Routine Immunization System in Bangladesh Dear Editor, We thank you and the reviewers for the thoughtful and constructive feedback on our manuscript. We have carefully revised the manuscript in response to all comments. Below, we provide a point-by-point response, indicating how each concern has been addressed. ________________________________________ Response to Editorial Requirements 1. Manuscript formatting and style: We have revised the manuscript to comply with PLOS ONE formatting guidelines using the templates provided. File names have also been updated per journal requirements. 2. Data availability and ethical restrictions: We have updated the Data Availability Statement to clarify that the data used in this study are obtained from the MIS unit of the Directorate General of Health Services (DGHS), Bangladesh. These data are not publicly shareable due to legal and ethical constraints regarding patient confidentiality and institutional data-sharing policies. • Reason for restriction: The dataset contains sensitive health service utilization information linked to administrative units and is governed by national surveillance confidentiality rules. • Authority imposing restriction: DGHS and the Institutional Review Board (IRB) of North South University (Memo No. 2022/OR-NSU/IRB/0406). • Data access contact: Interested researchers may request access from the DGHS MIS Unit via email at: mis@dghs.gov.bd ________________________________________ Reviewer #1 Comments Comment 1: Grammar and spelling improvements recommended. Response: Thank you. We have thoroughly reviewed and revised the manuscript using Grammarly and manual proofreading to improve grammar, spelling, and language clarity throughout the text. ________________________________________ Reviewer #2 Comments Comment 1: Clarify methodological details (sampling method, inclusion/exclusion criteria, study design). Response: We have revised the Methods section to clearly describe the study design (mixed-method study followed a nested design), sampling strategy ( sampling of data was not conducted whole data of January 2019–December 2021 were collected and for qualitative portion we have conducted KII according relevancy of stakeholder only relevants are included based on their involvement to the program In the revised Methods section, we have clarified that the study followed a sequential mixed-methods design. For the qualitative component, we used purposive sampling to select participants with direct involvement in routine immunization and VPD surveillance. A total of 10 Key Informant Interviews (KIIs) were conducted. The number of interviews was guided by the principle of data saturation, which was considered reached when no new themes or insights emerged from consecutive interviews, and key categories were fully developed. Saturation was monitored during data analysis using an iterative approach. This approach aligns with qualitative research standards (Guest et al., 2006; Fusch & Ness, 2015), where 6–12 interviews are often sufficient for studies with a relatively homogeneous group of experts. Comment 2: Define how key variables (exposure, outcome, covariates) were measured. Response: Thank you for this insightful comment. We have revised the Methods section to clearly define how key variables were conceptualized and measured in the quantitative analysis. Specifically, we clarified that the primary exposure variable was defined as distinct periods of COVID-19-related disruption in Bangladesh—namely March–April 2020 (first lockdown), December 2020 (second wave), and July 2021 (Delta variant surge). The main outcome variable was routine vaccination coverage, measured as the proportion of eligible children receiving scheduled antigens, including Bacillus Calmette–Guérin (BCG), Pentavalent-1, Pentavalent-3, and Measles-Rubella first dose (MR1), as reported in the District Health Information Software 2 (DHIS2). In addition, we specified a set of covariates used to explore contextual variation, such as sex, geographic region, urban versus rural location, hard-to-reach area classification, dropout and left-out rates, and the number of planned versus conducted immunization sessions. For vaccine-preventable disease (VPD) surveillance, performance was evaluated using trends in reported cases of measles-rubella (MR), acute flaccid paralysis (AFP), acute encephalitis syndrome (AES), and neonatal tetanus from the Excel-based EPI reporting system. These clarifications have been incorporated into the revised manuscript (Methods section, paragraph 3) to enhance transparency and methodological rigor. Comment 3: Improve statistical rigor (e.g., include measures of variability, significance). Response: We have revised the Results section to include appropriate summary statistics, confidence intervals, and p-values where applicable. Measures of change across time periods are now supported by descriptive trend analysis. Comment 4: Consider adding multivariable models to adjust for confounders. Response: We appreciate this suggestion. However, as the primary quantitative data were based on aggregate DHIS2 routine reporting, individual-level variables required for multivariable regression were not available. We have clarified this limitation in the Discussion and justified our use of descriptive time-series analysis. Comment 5: Expand the Discussion to contextualize findings in existing literature. Response: The Discussion section has been revised to better position our findings within the global literature on COVID-19 and immunization disruption, including comparisons with LMICs and WHO reports. We also discuss implications for health system resilience. Comment 6: Avoid overgeneralization of conclusions. Response: We have revised the conclusion to avoid any overstatement of causality and emphasized that findings should be interpreted in the context of an observational, exploratory study design. Comment 7: Revise figures and tables for clarity, define abbreviations. Response: All figures and tables have been revised for clarity where necessary. We thank you again for the opportunity to revise our work. We hope that the revised manuscript now meets the standards for publication in PLOS ONE. Sincerely, Dr. Md Foyjul Islam On behalf of all co-authors Email: drislam0666@gmail.com Attachments Attachment Submitted filename: Author Response.docx https://doi.org/10.1371/journal.pone.0334503.r002
25 Sep 2025 Decision Letter - Terna Nomhwange, Editor PONE-D-25-30097R1Impact of the COVID-19 pandemic on the routine immunization system in BangladeshPLOS ONE Dear Dr. Foyjul, 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. ============================== ACADEMIC EDITOR: Thank you for your revision and addressing previous comments made by reviewers Please include any study limitations as a subsection before the conclusion. I suggest a revision of the conclusion section to make it less wordy and more succinct. Please also review the current draft for consistency in the referencing style. In some cases, the reference is included at the end of sentences while in other cases this is included within a sentence. I suggest all references are consistently inserted at the end of a statement. You may wish to also include a foot note on the charts/Tables explaining why coverage levels reports are above 100%. ============================== Please submit your revised manuscript by Nov 09 2025 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. Please include the following items when submitting your revised manuscript: A rebuttal 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'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols . We look forward to receiving your revised manuscript. Kind regards, Terna Ignatius Nomhwange, MD,DTM&H,MBA Academic Editor PLOS ONE Journal Requirements: If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: All comments have been addressed Reviewer #3: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #3: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #3: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #3: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #3: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: (No Response) Reviewer #3: Thank you for your effort. A good research idea and accurate work. Hope you will continue your effort in future researches ****** 7. PLOS authors have the option to publish the peer review history of their article (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: No Reviewer #3: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org . Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0334503.r003
Revision 2
26 Sep 2025 Author Response attached as a document Attachments Attachment Submitted filename: Author_Response_auresp_2.docx https://doi.org/10.1371/journal.pone.0334503.r004
30 Sep 2025 Decision Letter - Terna Nomhwange, Editor Impact of the COVID-19 pandemic on the routine immunization system in Bangladesh PONE-D-25-30097R2 Dear Dr Foyjul Islam, 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, Terna Ignatius Nomhwange, MD,DTM&H,MBA Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0334503.r005
Formally Accepted
Acceptance Letter - Terna Nomhwange, Editor PONE-D-25-30097R2 PLOS ONE Dear Dr. Islam, 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 Dr. Terna Ignatius Nomhwange Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0334503.r006

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