PONE-D-21-11188

DRUL for School:  Opening Pre-K with safe, simple, sensitive saliva testing for SARS-CoV-2

PLOS ONE

Dear Dr. Darnell,

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Kanhaiya Singh, Ph.D

Academic Editor

PLOS ONE

Additional Editor Comments:

Although the article was well received by the reviewers, they have suggested some changes to make this study robust.

Journal Requirements:

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 If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references.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 If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

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2. Thank you for stating the following in the Competing Interests section:

"C.M.R acknowledges the generous support of the G. Harold and Leila Y. Mathers Charitable Foundation, the BAWD Foundation, and The Rockefeller University. R.B.D. wishes to disclose that he receives consulting fees as a Senior Visiting Fellow at MITRE Corporation, has started a charitable LLC, D4S Testing, to offer free DRUL saliva testing to NYC school children, and is an Investigator of the Howard Hughes Medical Institute."

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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

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

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: 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: Yes

Reviewer #3: No

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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

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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: I read with great interest the article from Darnell lab titled, 'DRUL for School: Opening Pre-K with safe, simple, sensitive saliva testing for SARS-CoV-2' It provides a practical solution to the current problem with opening of preK schools in the post-pandemic era.

The authors have shown scientific rigor and sound statistical analysis in the current study. It is written in a lucid manner.

Here are a few suggestions I would like to make to the authors:

1. References: i) ref 8,9,10 are missing in the introduction

ii) Sequence of references should also be looked into.

2. CDC has updated guidelines / operational strategies for K-12 schools to reopen. https://www.cdc.gov/coronavirus/2019-ncov/community/schools-childcare/operation-strategy.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fcommunity%2Fschools-childcare%2Fschools.html

A pertinent question to answer for the current manuscript is 'How does the DRUL saliva method fit in the context of these current guidelines?' especially considering the low risk of transmission amongst pre-K population.

3. The following points may be added to the discussion to make the utility DRUL saliva test more relevant in context of opening of schools:

i) Screening testing is particularly valuable in areas with moderate, substantial, and high levels of community transmission. Screening testing for K–12 schools may allow schools to move between different testing strategies as community prevalence (and therefore risk assessment) changes.

ii) Pooled tests for a cohort (pre-K students) may prove to be a feasible strategy. This approach increases the number of individuals that can be tested and reduces the need for testing resources.

Reviewer #2: It was of an immense pleasure for me to go through this article of Darnell Lab. It indeed addresses the need for simple, safe, sensitive, and scalable SARS-CoV-2 tests in this on going pandemic. I find this article to have a good statistical base and is scientifically developed.

Here are a few suggestions which I would like to bring into consideration:

1. TITLE: DRUL for School: Opening Pre-K with safe, simple, sensitive saliva testing for SARS-COV2.

even though this assay was used to aid in the reopening of a childcare center that enrolled children as young as three months old, it was used across a variety of ages and individuals with varied backgrounds; this title somewhat downplays its wide utility in various other workplaces where it can be of an exceptional use.

2. The DRUL buffer is based on the solution widely used in RNA extraction that contains [12].

This sentence on page no. 2 seems incomplete and needs appropriate completion.

3. Also references 9, 10 cannot be found mentioned in the content of this manuscript.

4. Antigen-based testing but not real-time polymerase chain reaction correlates with severe acute respiratory syndrome coronavirus 2 viral culture. Pekosz et al. Clinical Infectious Diseases (January 20, 2021).

This aspect can be further taken into consideration with a goal of increasing the PPV of the screening tests.

5. Also, instead of administering this test as a form of screening to each child, teacher and staff member weekly, along with inclusion of parents, it will be worthwhile to further assess the advantages of this method when the same assay is offered to test the pooled samples of small cohorts in a large group, or when clustered sampling can be done, in the setting of low prevalence of this infection.

Reviewer #3: The paper by Frank et al. aims at developing a PCR test using a self collected saliva sample kit at home for the detection of SARS-CoV-2.

Major Points:1, Please provide the figure2 to figure5 with the manuscript, as they are missing.

2, Please mention which statistical tools were used to analyze the data.

Minor Points: How long the individuals are instructed to avoid eating or using cleansing agents before collecting the samples? 30 mints ( mentioned in Specimen collection : Methods section) or 1 hour ( Mentioned in supplementary figure 1)

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

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DRUL for School:  Opening Pre-K with safe, simple, sensitive saliva testing for SARS-CoV-2

PONE-D-21-11188R1

Dear Dr. Darnell,

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,

Kanhaiya Singh, Ph.D

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Please address the minor comments made by Reviewer 3 during the proofreading stage.

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 #2: All comments have been addressed

Reviewer #3: 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

Reviewer #2: Yes

Reviewer #3: Yes

**********

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

Reviewer #1: Yes

Reviewer #2: 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 #2: Yes

Reviewer #3: Yes

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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

Reviewer #2: Yes

Reviewer #3: 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 concerns raised by the previous reviewers have been addressed very nicely.

To be honest, reviewing this paper has been a privileged learning experience for me.

Such data needs to come out in public domain at earliest.

Thank you.

Reviewer #2: (No Response)

Reviewer #3: Author addressed all the comments. Author should correct the minor issues in the manuscript before submitting the final version to the journal

e.g:

1,At DRUL buffer to virus ratio 1:5 concentration, 3.41 x 106 PFU/ml viral particles mentioned in Results section, but table in Figure 5 predicts different number.

2, Reference 14 is missing.

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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

Reviewer #2: No

Reviewer #3: No