Dear Dr BARRY,

Thank you very much for submitting your manuscript "Helminth exposure and immune response to the two-dose heterologous Ad26.ZEBOV, MVA-BN-Filo Ebola vaccine regimen" for consideration at PLOS Neglected Tropical Diseases. As with all papers reviewed by the journal, your manuscript was reviewed by members of the editorial board and by several independent reviewers. The reviewers appreciated the attention to an important topic. Based on the reviews, we are likely to accept this manuscript for publication, providing that you modify the manuscript according to the review recommendations.

Please prepare and submit your revised manuscript within 30 days. If you anticipate any delay, please let us know the expected resubmission date by replying to this email.

When you are ready to resubmit, please upload the following:

[1] A letter containing a detailed list of your responses to all review comments, and a description of the changes you have made in the manuscript.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out

[2] Two versions of the revised manuscript: one with either highlights or tracked changes denoting where the text has been changed; the other a clean version (uploaded as the manuscript file).

Important additional instructions are given below your reviewer comments.

Thank you again for your submission to our journal. We hope that our editorial process has been constructive so far, and we welcome your feedback at any time. Please don't hesitate to contact us if you have any questions or comments.

Sincerely,

Eva Clark

Section Editor

PLOS Neglected Tropical Diseases

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Reviewer's Responses to Questions

Key Review Criteria Required for Acceptance?

As you describe the new analyses required for acceptance, please consider the following:

Methods

-Are the objectives of the study clearly articulated with a clear testable hypothesis stated?

-Is the study design appropriate to address the stated objectives?

-Is the population clearly described and appropriate for the hypothesis being tested?

-Is the sample size sufficient to ensure adequate power to address the hypothesis being tested?

-Were correct statistical analysis used to support conclusions?

-Are there concerns about ethical or regulatory requirements being met?

Reviewer #1: - The authors have adeptly delineated both the primary and secondary objectives of the study.

- The study design demonstrates a high level of validity.

- The description of the study population is lucid and comprehensive.

- The calculated sample size aligns well with the scope of the study.

- The utilization of appropriate statistical analyses enhances the rigor of the study. However, it's important to note that while the authors state using RStudio for data analysis, it's worth clarifying that R programming was the actual tool employed. RStudio serves as a user-friendly interface for R programming and should be appropriately distinguished from the underlying analytical language. (Line 250, page9)

- On line 182, page 6, it was mentioned that participants from each initial study were randomly chosen. Could you please clarify if the number from each study was taken in proportion, or if all participants were combined and then selected randomly? This clarification would help readers better understand the process.

- Addressing a minor concern, it remains unclear if this study is an extension of the previously mentioned clinical trials, thus potentially obviating the need for new ethical approval. It would be beneficial for the authors to elaborate in more explicit terms on how they ensured adherence to ethical requirements in light of this potential continuity with previous trials.

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Results

-Does the analysis presented match the analysis plan?

-Are the results clearly and completely presented?

-Are the figures (Tables, Images) of sufficient quality for clarity?

Reviewer #1: - The executed analyses are consistent with the authors' outlined methodology.

- The presentation of results is notably clear and comprehensible.

- Figure 1 is easy to comprehend, but its quality seems to be suboptimal. It might be beneficial to enlarge the numbers within the figure, as they appear quite small at present.

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Conclusions

-Are the conclusions supported by the data presented?

-Are the limitations of analysis clearly described?

-Do the authors discuss how these data can be helpful to advance our understanding of the topic under study?

-Is public health relevance addressed?

Reviewer #1: - The conclusions drawn align logically with the presented data.

- The limitations of the study are distinctly articulated.

- Given that the study's outcomes indicate an absence of linkage between immune markers of helminth exposure and post-vaccination response, it would be advantageous for the authors to delve into potential factors contributing to the varying immunogenicity of the Ebola vaccine across diverse regions. This could serve to capture readers' attention and foster future research initiatives.

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Editorial and Data Presentation Modifications?

Use this section for editorial suggestions as well as relatively minor modifications of existing data that would enhance clarity. If the only modifications needed are minor and/or editorial, you may wish to recommend “Minor Revision” or “Accept”.

Reviewer #1: I have no additional comments to contribute in this section.

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Summary and General Comments

Use this section to provide overall comments, discuss strengths/weaknesses of the study, novelty, significance, general execution and scholarship. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. If requesting major revision, please articulate the new experiments that are needed.

Reviewer #1: Barry and colleagues undertook a cross-sectional study aimed at assessing the correlation between immune markers indicative of helminth exposure and the immunogenic response following vaccination with Ebola vaccines. The study is well-written and focuses on a captivating topic. In brief, the research methods, results, and conclusions presented in the study are robust and well-founded. I have a few comments to contribute.

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Reviewer #1: No

Figure 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. 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 us at figures@plos.org.

Data Requirements:

Please note that, as a condition of publication, PLOS' data policy requires that you make available all data used to draw the conclusions outlined in your manuscript. Data must be deposited in an appropriate repository, included within the body of the manuscript, or uploaded as supporting information. This includes all numerical values that were used to generate graphs, histograms etc.. For an example see here: http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001908#s5.

Reproducibility:

To enhance the reproducibility of your results, we recommend that you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. Additionally, PLOS ONE offers an option to publish peer-reviewed clinical study protocols. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols

References

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.

Dear Dr BARRY,

We are pleased to inform you that your manuscript 'Helminth exposure and immune response to the two-dose heterologous Ad26.ZEBOV, MVA-BN-Filo Ebola vaccine regimen' has been provisionally accepted for publication in PLOS Neglected Tropical Diseases.

Before your manuscript can be formally accepted you will need to complete some formatting changes, which you will receive in a follow up email. A member of our team will be in touch with a set of requests.

Please note that your manuscript will not be scheduled for publication until you have made the required changes, so a swift response is appreciated.

IMPORTANT: The editorial review process is now complete. PLOS will only permit corrections to spelling, formatting or significant scientific errors from this point onwards. Requests for major changes, or any which affect the scientific understanding of your work, will cause delays to the publication date of your manuscript.

Should you, your institution's press office or the journal office choose to press release your paper, you will automatically be opted out of early publication. We ask that you notify us now if you or your institution is planning to press release the article. All press must be co-ordinated with PLOS.

Thank you again for supporting Open Access publishing; we are looking forward to publishing your work in PLOS Neglected Tropical Diseases.

Best regards,

Eva Clark, M.D., Ph.D.

Section Editor

PLOS Neglected Tropical Diseases

Eva Clark

Section Editor

PLOS Neglected Tropical Diseases

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Reviewer's Responses to Questions

Key Review Criteria Required for Acceptance?

As you describe the new analyses required for acceptance, please consider the following:

Methods

-Are the objectives of the study clearly articulated with a clear testable hypothesis stated?

-Is the study design appropriate to address the stated objectives?

-Is the population clearly described and appropriate for the hypothesis being tested?

-Is the sample size sufficient to ensure adequate power to address the hypothesis being tested?

-Were correct statistical analysis used to support conclusions?

-Are there concerns about ethical or regulatory requirements being met?

Reviewer #1: The methodology section is well-crafted, addressing previous comments from peer reviewers effectively. The clarity and detail provided here lay a solid foundation for understanding the study's design and execution. I appreciate the effort to refine this section based on prior feedback, which has undoubtedly strengthened the manuscript. No further suggestions at this point.

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Results

-Does the analysis presented match the analysis plan?

-Are the results clearly and completely presented?

-Are the figures (Tables, Images) of sufficient quality for clarity?

Reviewer #1: Improvements to the figures are notable and significantly enhance the reader's comprehension of the findings. The revised figures are now clear and effectively convey the study's results. This enhancement has substantially improved the manuscript's quality, allowing for a straightforward interpretation of the data presented. I commend your response to the feedback on earlier drafts, resulting in this improvement. No additional comments here.

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Conclusions

-Are the conclusions supported by the data presented?

-Are the limitations of analysis clearly described?

-Do the authors discuss how these data can be helpful to advance our understanding of the topic under study?

-Is public health relevance addressed?

Reviewer #1: The conclusion is well-articulated, providing a compelling summary of the study's findings and their implications. The addition of more detailed information has not only made the manuscript more informative but also more engaging for readers. This section does an excellent job of capturing the study's significance and potential impact on the field. The authors' efforts to enhance this section based on previous reviews are evident and appreciated. No further recommendations for this section.

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Editorial and Data Presentation Modifications?

Use this section for editorial suggestions as well as relatively minor modifications of existing data that would enhance clarity. If the only modifications needed are minor and/or editorial, you may wish to recommend “Minor Revision” or “Accept”.

Reviewer #1: I have no additional comment.

**********

Summary and General Comments

Use this section to provide overall comments, discuss strengths/weaknesses of the study, novelty, significance, general execution and scholarship. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. If requesting major revision, please articulate the new experiments that are needed.

Reviewer #1: The manuscript by Barry and colleagues, detailing a substudy nested within clinical trials, is commendably written and explores an intriguing topic: the association between participants’ immune responses to the Ebola vaccine and their history of helminthic parasites infection. I have no more comment to add.

In general, this manuscript is a significant contribution to the field, effectively bridging a gap in our understanding of the immune response to the Ebola vaccine in the context of helminthic parasite infections. The study is well-presented, and the revisions made in response to prior peer reviews have notably enhanced its clarity and depth. I look forward to seeing the final version published.

**********

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