PONE-D-21-30742Seroprevalence of COVID-19 infection among vaccine naïve population after the second surge (June 2020) in a rural district of South India: a community-based cross-sectional studyPLOS ONE

Dear Dr. Inbaraj,

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.

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ACADEMIC EDITOR:

We apologize for the delay in processing this manuscript. While the study is of significant interest, there are several key issues that need to be addressed in a revised manuscript: 1. The Methods section states that seroprevalence was quantified using an assay that measures primarily IgG and some IgA + IgM antibodies against RBD. The Abstract states that IgG and IgM antibodies against RBD were quantified. This discrepancy needs to be resolved. More importantly, can the authors provide relative abundance levels of IgG and IgM antibodies? This would for obvious reasons provide key insights into the duration of infection. These analyses should either be added, or if the data is unavailable, this should explicitly be discussed as a study limitation. 2. The study was carried out in a population that hadn't received a COVID-19 vaccine. Given the timeline of the study, this could be either due to lack of access to a COVID-19 vaccine or general vaccine hesitancy. However, are other vaccination records available for these individuals? This information may help identify 2 sub-groups in the population - a) those that have completed recommended vaccination regimens for other vaccines i.e., they had likely not received a COVID-19 vaccine at the time of the study due to lack of access (potentially lower risk group), and b) those that had not completed recommended vaccination regimens even for other vaccines i.e., they likely have general vaccine hesitancy (potentially higher risk group). Are there indeed differences in seropositivity between these 2 groups? 3. Table 3 provides insights into how univariate factors are associated with seroprevalence. The insights from this table are limited as the significant univariate factors are the "obvious" ones (symptoms, positive test for individual or family members). It would be much more interesting to examine the contributions of the "non-obvious" features to seroprevalence risk in a multivariate setting (potentially also accounting for interaction terms). 4. From a presentation standpoint, the manuscript would benefit significantly from some figures/visual representations that summarize the data currently presented as tables.

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Kind regards,

Jishnu Das, Ph.D.

Academic Editor

PLOS ONE

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Seroprevalence of COVID-19 infection among vaccine naïve population after the second surge (June 2020) in a rural district of South India: a community-based cross-sectional study

PONE-D-21-30742R1

Dear Dr. Inbaraj,

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.

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Kind regards,

Jishnu Das, Ph.D.

Academic Editor

PLOS ONE

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