PONE-D-22-35165Low prevalence of current and past SARS-CoV-2 infections among visitors and staff members of homelessness services in Amsterdam at the end of the second wave of infections in the NetherlandsPLOS ONE

Dear Dr. Generaal,

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Ian Christopher N Rocha, MD, MBA, MHSS

Academic Editor

PLOS ONE

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Additional Editor Comments:

Dear Authors,

Thank you for submitting an interesting manuscript. Kindly address the comments and suggestions of the four reviewers.

Best regards,

Academic Editor

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. 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 #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: I Don't Know

Reviewer #3: Yes

Reviewer #4: No

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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: No

Reviewer #2: No

Reviewer #3: No

Reviewer #4: Yes

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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

Reviewer #3: Yes

Reviewer #4: Yes

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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: Very nice paper, nicely written and clearly explained. Please address the questions below to further improve clarity.

-Lines 53-55: Clarify whether antibody results were restricted to those without prior COVID-19 vaccination.

-Lines 57-58: Rephrase intention to vaccinate and trust in COVID-19 policies to indicate that the “majority” of respondents had low or medium intention to vaccinate/trust in policies.

Reviewer #2: Congratulations to the authors on the successful completion of their study.

The authors in this study analyze the prevalence of current and past SARS CoV-2 infection in People Experiencing Homelessness(PEH) in visitors and staff members of homelessness services in Amsterdam. According to the authors, the study was conducted during May 2021 when the second wave of COVID in Netherlands was over. The authors have also highlighted the fact that this is a first of its kind of study in Netherlands. The authors claim that they observed a low prevalence of past and current SARS CoV-2 infection rates among the PEH which they hypothesize can be attributed to escalated efforts on part of the dutch government to offer shelters with closed spaces for the PEH. While the manuscript presents techincally and scientifically sound data to support this claim, the inherent significance of this study could not be understood. The authors have claimed that these findings are contrary to the ones that have been previously reported from countries like France and US and even Netherlands for that matter. The authors mention that higher SARS CoC-2 prevalence in these studies could have been because of sampling from ares that had outbreaks. The findings reported are true to their core and the data presented supports it as well but a mention of the significance of conducting and publishing such a study is missing. The authors are encouraged to discuss the significance of this study in detail. And as a minor correction, the authors are advised to reframe the short title of this study.

Reviewer #3: The manuscript is well thought out and written, the objectives are clearly stated, the methods are adequate, data statistically analyzed, the conclusions well supported by the data presented. This paper is well-written and I enjoy reading through it. The authors should consider the following recommendations in order to improve the original manuscript:

[1] Abstract. Some sentences are not easy to understand: "Intention to vaccinate for COVID-19 was low (30% for visitors, 10% for staff) or medium (28% for visitors, 35% for staff). Trust in COVID-19 policies was either low (27% for visitors, 17% for staff) or neutral (32% for visitors, 53% for staff)."

[2] All participants provided written informed consent. Were there no illiterate participants? How was consent obtained from participants of Polish origin? Was there a consent form written in Polish?

[3] Since the internal consistency of the statements demonstrated high reliability (Cronbach’s α=0.95), their responses were combined as a mean score. Cronbach’s coefficient is useful to examine the internal consistency of the constructs used in the study, but they are not useful for indicating whether the mean of the responses to the items is adequate for the data analyses.

[4] Vaccination intention was categorized into low (mean score 1.0-2.5), medium (3.0-5.0) and high (5.5-7.0), based on the distribution of the combined score. Please be clearer about the criteria used to establish these cut-off points.

Reviewer #4: How does the sample size with your studies compare to other studies?

There were no formal statistical test compared

Very few patients are test positive, but does it represented the whole population?

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

Reviewer #4: No

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Low prevalence of current and past SARS-CoV-2 infections among visitors and staff members of homelessness services in Amsterdam at the end of the second wave of infections in the Netherlands

PONE-D-22-35165R1

Dear Dr. Generaal,

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.

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Kind regards,

Ian Christopher N Rocha, MD, MBA, MHSS

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

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

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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

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

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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: No

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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

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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: All comments have been adequately addressed. Reasons for not making data available need to be made explicit in the Data Availability Statement.

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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

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