Analysis of some factors and COVID-19 mortality in the population of 0 to 24 years in 29 countries: schools could be a protection

Background. It is limited literature on the possible factors related to mortality by COVID-19 in minors. Children and young people are generally considered vulnerable, especially in low-income countries, whereby consistent evidence must arise to protect them and avoid mortality. Methods. A multiple linear regression model was fit to evaluate the relationship between deaths per 100,000 inhabitants and pandemic containment policies, the duration of totally closed schools, and GDP in 29 countries under study. Results. Linear regression analysis shows that the association between deaths per 100k and the number of weeks of closed schools had a coef B=0.355, [CI 0.010; 0.699], and it is statistically significant (P-value =0.044). Similarly, the association between deaths per 100K and GDP was -0.001, [CI -0.003; 0.001], and is not statistically associated (P-value 0.633). Conclusions. This study suggests that open schools could be a protective space for COVID-19 mortality in the child and youth population and that each country should implement studies on the subject at the local level.

5. Ethical aspects. Does the manuscript have a paragraph on ethical aspects, where it mentions approval by the ethics committee, informed consent, and strict compliance with research ethics? No 6. Results: They are presented adequately and it is not redundant with tables or graphs shown. Good

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Results are well presented.
7. Discussion: They present a level of critical analysis in correspondence with the problem presented. Purposes of the article, scope, support theory and proposed methodological design. Good

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Despite scarcity in knowledge in this area, authors made good attempts to present a robust discussion that is satisfactory. 8. Conclusions: Presents the author's inferences and teachings in relation to the investigated topic, it must correspond to the objectives of the study.

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Conclusion can be improved on. See the attached corrected version of the manuscript. 9. References. Quality of bibliographic references and if they are in accordance with the Vancouver format.

Regular
Remarks Some references are incomplete.
10. Redaction. Is the manuscript correctly written? Does it contain any spelling or grammar mistakes? Needs some language corrections 11. Contributions. What are the main weaknesses of the manuscript and how the author can do to improve it The service of a professional English language editor can be sought for so as to improve on the quality of the manuscript.
Relevance of the title to the content of the article Regular

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The title is too long.
2. Summary: Presents the general idea of the topic, objectives, research methods, results and conclusions, written in an objective and concise manner; and are found according to the maximum number of words per section. Poor

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The document has no abstract 3. Introduction: Presentation of the subject, justification of the problem, objectives, hypotheses and methodological foundation, exposing the subject in an orderly and detailed manner Poor Remarks there are many paragraphs without a bibliographic citation, the veracity of the information is not guaranteed 4. Methodology: Describes the procedure, methods and techniques used in data collection and analysis. Poor

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The methodology does not have bibliographic support, only that they are a methodology developed by the authors should not be supported by other documents 5. Ethical aspects. Does the manuscript have a paragraph on ethical aspects, where it mentions approval by the ethics committee, informed consent, and strict compliance with research ethics? No 6. Results: They are presented adequately and it is not redundant with tables or graphs shown. Poor

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The results are not displayed correctly 7. Discussion: They present a level of critical analysis in correspondence with the problem presented. Purposes of the article, scope, support theory and proposed methodological design.

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The ideas are short and have no sequence, a detailed review of similar documents was not carried out 8. Conclusions: Presents the author's inferences and teachings in relation to the investigated topic, it must correspond to the objectives of the study. Poor

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The document has no conclusion 9. References. Quality of bibliographic references and if they are in accordance with the Vancouver format. Regular 10. Redaction. Is the manuscript correctly written? Does it contain any spelling or grammar mistakes? Needs some language corrections 11. Contributions. What are the main weaknesses of the manuscript and how the author can do to improve it The document in its current version does not have the minimum elements to be published, the authors must have a consistent title that is related to the objective and, above all, an excellent methodology.
Relevance of the title to the content of the article Good 2. Summary: Presents the general idea of the topic, objectives, research methods, results and conclusions, written in an objective and concise manner; and are found according to the maximum number of words per section. Good 3. Introduction: Presentation of the subject, justification of the problem, objectives, hypotheses and methodological foundation, exposing the subject in an orderly and detailed manner Regular 4. Methodology: Describes the procedure, methods and techniques used in data collection and analysis. Regular 5. Ethical aspects. Does the manuscript have a paragraph on ethical aspects, where it mentions approval by the ethics committee, informed consent, and strict compliance with research ethics? Yes 6. Results: They are presented adequately and it is not redundant with tables or graphs shown. Regular 7. Discussion: They present a level of critical analysis in correspondence with the problem presented. Purposes of the article, scope, support theory and proposed methodological design. Regular 8. Conclusions: Presents the author's inferences and teachings in relation to the investigated topic, it must correspond to the objectives of the study. Regular 9. References. Quality of bibliographic references and if they are in accordance with the Vancouver format. Regular 10. Redaction. Is the manuscript correctly written? Does it contain any spelling or grammar mistakes? Needs some language corrections 11. Contributions. What are the main weaknesses of the manuscript and how the author can do to improve it Hello . It is an interesting article, but there are some questions that should be explained in the article. 1-In my opinion, the closing of schools is related to the mortality of all ages. Most of the young people are asymptomatic carriers, which transmit to high-risk individuals. Why have you not calculated the total mortality? 2. You have not calculated the death rate and the percentage of associated diseases, for example, in Israel there are many family marriages, which increases the risk of congenital anomalies. We have now completely revised the manuscript, considering all reviewers' comments. We have supposed and included each reviewer's suggestion and did our best to reply to every comment and make the necessary changes to the document.
We look forward to the decision on our manuscript. Sincerely, Jesús D Cortés, on behalf of all authors Answers: We want to thank the reviewers for their highly relevant comments and suggestions, which will undoubtedly make this manuscript a better study.
-The title was altered as suggested by the reviewers. -The abstract is now placed at the top along with the keywords for greater visibility and has been adjusted according to the recommendations. -The introduction was edited to better organize the ideas into longer paragraphs, inserting two references suggested by one of the reviewers.
-The methods were written more compactly to improve the reader's understanding, and some technical and vocabulary changes were included. -The results were described in a more orderly way to facilitate reading, and some words were modified, observations for which we are very grateful to a reviewer in particular, who we intuit was a clinical expert on the subject of COVID-19.
-The discussion was re-edited, and the limitations/strengths and conclusions were included separately at the end to respond to the reviewers' suggestions.
-Mortality rates have already been calculated by the organizations above that monitor the information, which is why we did not do this labor.
-The declaration of ethical approval was included separately; since it is public data reported by each country, the agencies that monitor it already take it for granted that each country rigorously guaranteed ethical principles.
-The references were revised, to the Vancouver format, using the Mendeley program.
To finish, we again reviewed the English grammar, using the Advanced Grammarly software, and for ourselves the entire manuscript to make it more understandable.