Omicron surge impact on acute kidney injury in ICU patients: A study using the ISARIC COVID-19 database

Danyang Dai; Pedro Franca Gois; Marina Wainstein; Moji Ghadimi; Nicholas Spyrison; Rolando Claure-Del Granado; Sally Shrapnel; Jason D. Pole; ISARIC Characterization Group

doi:10.1371/journal.pone.0336843

Peer Review History

Original SubmissionApril 14, 2025
3 Aug 2025 Decision Letter - Vipa Thanachartwet, Editor Dear Dr. Pole, 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. We appreciate the interesting study. However, there are some points raised by the reviewers. Please carefully respond to the reviewer comments and suggestions. Please submit your revised manuscript by Sep 17 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. 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Thank you for stating in your Funding Statement: “DD is supported by the University of Queensland’s Research and Training Scholarship and Digital Health UQ-QH Alliance Scholarship. SS is supported by ARC CoE Engineered Quantum Systems. DD, SS and NS declared funding from Artificial Intelligence for Pandemics (A14PAN) at University of Queensland. This work was made possible with the support of the UK Foreign, Commonwealth and Development Office and Wellcome [215091/Z/18/Z, 222410/Z/21/Z, 225288/Z/22/Z and 220757/Z/20/Z]; the Bill & Melinda Gates Foundation [OPP1209135].” Please provide an amended statement that declares all the funding or sources of support (whether external or internal to your organization) received during this study, as detailed online in our guide for authors at http://journals.plos.org/plosone/s/submit-now. Please also include the statement “There was no additional external funding received for this study.” in your updated Funding Statement. Please include your amended Funding Statement within your cover letter. We will change the online submission form on your behalf. 3. Thank you for stating the following financial disclosure: “DD is supported by the University of Queensland’s Research and Training Scholarship and Digital Health UQ-QH Alliance Scholarship. SS is supported by ARC CoE Engineered Quantum Systems. DD, SS and NS declared funding from Artificial Intelligence for Pandemics (A14PAN) at University of Queensland. This work was made possible with the support of the UK Foreign, Commonwealth and Development Office and Wellcome [215091/Z/18/Z, 222410/Z/21/Z, 225288/Z/22/Z and 220757/Z/20/Z]; the Bill & Melinda Gates Foundation [OPP1209135].” Please state what role the funders took in the study. If the funders had no role, please state: "The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript." 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Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information. 10. If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. [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? Reviewer #1: Yes Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? -->?> Reviewer #1: Yes Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available??> The PLOS Data policy Reviewer #1: Yes Reviewer #2: No ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English??> Reviewer #1: Yes Reviewer #2: Yes ****** Reviewer #1: I would like to thank the editor and authors for the opportunity to review this very interesting manuscript on the Omicron Impact on Acute Kidney Injury in ICU Patients. The manuscript is well written, the methods used allow a interpretable results which could be discussed. We would like to highlights some points which could improve the present manuscript. Introduction Nevertheless, compared to the earlier Delta variant, it has been associated with higher serum creatinine levels on admission to hospital, denoting greater renal impact [8] A single-centre study revealed a three-fold higher prevalence of AKI among intensive care unit (ICU) patients infected with the Omicron versus the Delta variant. However, the study was limited to 65 patients from a single centre who stayed in the ICU [14] • The authors used two references that reported a high prevalence of AKI in patients in the Omicron group and developed their research hypothesis based on these references We are not certain that all studies have reported this result, which seems to contradict the trend towards a reduction in the severity of COVID-19 over time since the appearance of COVID-19 corresponding to viral mutations, improved management with, for example, the use of corticosteroids, and the positive impact of vaccination. The authors could use the reference below (Nlandu, Y., Makulo, J. R., Essig, M., Sumaili, E., Lumaka, A., Engole, Y., … Nseka, N. (2023). Factors associated with acute kidney injury (AKI) and mortality in COVID-19 patients in a Sub-Saharan African intensive care unit: a single-center prospective study. Renal Failure, 45(2). https://doi.org/10.1080/0886022X.2023.2263583) where the authors reported a significantly higher prevalence of AKI-3 requiring dialysis during the first wave compared with others, in particular the 4th wave which corresponds to the omicron period. This could highlight the difference in the results of the various studies limited by their monocentric nature and the small size of their sample. This could further justify their study. Methods "Pre-Omicron" for admissions before December 1, 2021, and "Omicron" for admissions after January 1, 2022. These dates were chosen as they reflect the point at which the Omicron variant frequency reached 90% in the countries included in this study. • Failure to specify the viral variant by genetic sequencing could introduce a bias in the selection of patients and therefore in the interpretation of results, particularly in the context of low-income countries where, in the absence of vaccination, two variants of concern may be found concomitantly during the same period. The 90% threshold does not exclude the residual risk of recording a greater number of patients with a variant other than omicron. The authors should emphasize this within the limits of their study. There were no clinical flags in the datasets that identified specific variants, it was not feasible to discriminate patients infected with the Omicron variant from pre-Omicron variants in December 2021 thus these data were excluded • This is not enough to exclude patients with other variants. Discussion The Chinese study reported one AKI patient for Omicron hospitalized patients and no AKI patient was recorded for Delta patients [8] • This study was used to justify the possible high prevalence of renal failure in the context of Omicron in the “introduction” section of the manuscript and in the “discussion” section its interpretation changes towards a low prevalence of AKI. We feel that it should not be used in the introduction as it has not reported a trend towards a high prevalence of AKI. Few studies have explored the risk factors associated with AKI development and COVID-19 • I'm not sure that this sentence is correct, given the number of studies on COVID-19 that we currently have. Reviewer #2: The authors describe results of a paper investigating differences in factors related to AKI among hospitalized patients with COVID-19 during and before the Omicron variant surges using a large dataset from multiple countries. I have the following comments/suggestions: Methods: What were the variables of interest that were imputed or excluded due to >20% missingness? Methods: What was the rationale to use a logistic model instead of another method that would incorporate the time-to-event data, like Cox regression? Methods: “The follow-up duration was calculated in days, starting from the first day of hospital admission and concluding with the earliest date of discharge, death or transfer to another hospital.” Methods: Do we know to what extent the same hospitals are used in the pre-Omicron and Omicron periods? Should follow-up also end if the patient develops the event (AKI)? Also, in the case of transfer to another hospital, if we are unable to continue to follow them up at the other hospital, do we have any indication of differences between patients who are or are not transferred and how that may or may not affect the results? Table 2: This is a large table with the primary findings, so some clarification can be useful. 1) We can explicitly state the association that is described by the models in the title. 2) Sample sizes for each analyses can also be useful (e.g. can indicate the degree of missingness when comparing findings). 3) Three sets of analyses appear that are labeled “Data 1, Imputed data,” “Data 2, Listwise deletion,” and “Data 3, 6”. What is this last one? 4) The comparisons made or the reference group for each odds ratio are not clear. For some, though it’s not explicit, we can assume (e.g. female vs. male, diabetes vs no diabetes), though for others it’s not clear. For example, for the continuous variables and the countries. All these can be made explicit in the rows or for brevity, in the footnotes. Given the large amount of covariates in Model 3, could it be overfit? Were propensity scores considered? ****** what does this mean? ). 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Revision 1
3 Sep 2025 Author Response Please see our responses to the Academic editor’s comments with journal requirements: Journal Requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf Response: We thank the editor for providing the references. We have reformatted our manuscript to align with the journal requirement. 2. Thank you for stating in your Funding Statement: “DD is supported by the University of Queensland’s Research and Training Scholarship and Digital Health UQ-QH Alliance Scholarship. SS is supported by ARC CoE Engineered Quantum Systems. DD, SS and NS declared funding from Artificial Intelligence for Pandemics (A14PAN) at University of Queensland. Please provide an amended statement that declares all the funding or sources of support (whether external or internal to your organization) received during this study, as detailed online in our guide for authors at http://journals.plos.org/plosone/s/submit-now. Please also include the statement “There was no additional external funding received for this study.” in your updated Funding Statement. Please include your amended Funding Statement within your cover letter. We will change the online submission form on your behalf. Response: Please see the justified funding statement below: DD is supported by the University of Queensland’s Research and Training Scholarship and Digital Health UQ-QH Alliance Scholarship. SS is supported by ARC CoE Engineered Quantum Systems. DD, SS and NS declared funding from Artificial Intelligence for Pandemics (A14PAN) at University of Queensland. The ISARIC Clinical Epidemiology Platform used for this work was supported by the Wellcome Trust [303666/Z/23/Z]; UK International Development [301542-403]; and the Gates Foundation [INV-063472]. There was no additional external funding received for this study. 3. Thank you for stating the following financial disclosure: “DD is supported by the University of Queensland’s Research and Training Scholarship and Digital Health UQ-QH Alliance Scholarship. SS is supported by ARC CoE Engineered Quantum Systems. DD, SS and NS declared funding from Artificial Intelligence for Pandemics (A14PAN) at University of Queensland. Please state what role the funders took in the study. If the funders had no role, please state: "The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript." If this statement is not correct you must amend it as needed. Please include this amended Role of Funder statement in your cover letter; we will change the online submission form on your behalf. Response: Please see the Financial disclosure below: DD is supported by the University of Queensland’s Research and Training Scholarship and Digital Health UQ-QH Alliance Scholarship. SS is supported by ARC CoE Engineered Quantum Systems. DD, SS and NS declared funding from Artificial Intelligence for Pandemics (A14PAN) at University of Queensland. The ISARIC Clinical Characterisation Group is supported by the Wellcome Trust [303666/Z/23/Z]; UK International Development [301542-403]; and the Gates Foundation [INV-063472]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. 4. Thank you for stating the following in the Competing Interests section: “CDG is a member at large of the ISNB Executive Committee, co-chair of the SLANH AKI Committee and Deputy Chair of the ISN Fellowship committee.” Please confirm that this does not alter your adherence to all PLOS ONE policies on sharing data and materials, by including the following statement: "This does not alter our adherence to PLOS ONE policies on sharing data and materials.” (as detailed online in our guide for authors http://journals.plos.org/plosone/s/competing-interests). If there are restrictions on sharing of data and/or materials, please state these. Please note that we cannot proceed with consideration of your article until this information has been declared. Please include your updated Competing Interests statement in your cover letter; we will change the online submission form on your behalf. Response: Please see the updated Competing Interests below: CDG is a member at large of the ISNB Executive Committee, co-chair of the SLANH AKI Committee and Deputy Chair of the ISN Fellowship committee. This does not alter our adherence to PLOS ONE policies on sharing data and materials. 5. We note that you have indicated that there are restrictions to data sharing for this study. For studies involving human research participant data or other sensitive data, we encourage authors to share de-identified or anonymized data. However, when data cannot be publicly shared for ethical reasons, we allow authors to make their data sets available upon request. For information on unacceptable data access restrictions, please see http://journals.plos.org/plosone/s/data-availability#loc-unacceptable-data-access-restrictions. Before we proceed with your manuscript, please address the following prompts: a) If there are ethical or legal restrictions on sharing a de-identified data set, please explain them in detail (e.g., data contain potentially identifying or sensitive patient information, data are owned by a third-party organization, etc.) and who has imposed them (e.g., a Research Ethics Committee or Institutional Review Board, etc.). Please also provide contact information for a data access committee, ethics committee, or other institutional body to which data requests may be sent. b) If there are no restrictions, please upload the minimal anonymized data set necessary to replicate your study findings to a stable, public repository and provide us with the relevant URLs, DOIs, or accession numbers. Please see http://www.bmj.com/content/340/bmj.c181.long for guidelines on how to de-identify and prepare clinical data for publication. For a list of recommended repositories, please see https://journals.plos.org/plosone/s/recommended-repositories. You also have the option of uploading the data as Supporting Information files, but we would recommend depositing data directly to a data repository if possible. Please update your Data Availability statement in the submission form accordingly. Response: We have updated our Data Availability statements, please see below: The data that underpin this analysis are highly detailed clinical data on individuals hospitalised with COVID-19. Due to the sensitive nature of these data and the associated privacy concerns, they are available via a governed data access mechanism following review and approval by a data access committee. Data can be requested via the IDDO COVID-19 Data Sharing Platform (http://www.iddo.org/covid-19). The Data Access Application, Terms of Access and details of the Data Access Committee are available on the website. Briefly, the requirements for access are a request from a qualified researcher working with a legal entity who have a health and/or research remit; a scientifically valid reason for data access which adheres to appropriate ethical principles. The full terms are at https://www.iddo.org/document/covid-19-data-access-guidelines. 6. One of the noted authors is a group or consortium [ISARIC Characterization Group]. In addition to naming the author group, please list the individual authors and affiliations within this group in the acknowledgments section of your manuscript. Please also indicate clearly a lead author for this group along with a contact email address. Response: Please see members of the ISARIC Characterization Group attached. We would need to make each of the members a citable author. The attached file contains the members’ name and affiliations. Thank you. 7. We note that you have included the phrase “data not shown” in your manuscript. Unfortunately, this does not meet our data sharing requirements. PLOS does not permit references to inaccessible data. We require that authors provide all relevant data within the paper, Supporting Information files, or in an acceptable, public repository. Please add a citation to support this phrase or upload the data that corresponds with these findings to a stable repository (such as Figshare or Dryad) and provide and URLs, DOIs, or accession numbers that may be used to access these data. Or, if the data are not a core part of the research being presented in your study, we ask that you remove the phrase that refers to these data. Response: We thank the Academic editor for pointing this out. We have added the additional supporting information in the supplementary materials (S-Table 4) and addressed this in the manuscript. 8. Your ethics statement should only appear in the Methods section of your manuscript. If your ethics statement is written in any section besides the Methods, please move it to the Methods section and delete it from any other section. Please ensure that your ethics statement is included in your manuscript, as the ethics statement entered into the online submission form will not be published alongside your manuscript. Response: We have made sure that the ethics statement only appears in the Methods section. 9. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information. Response: We thank the editor for providing the details. We have included captions for the Supporting Information at the end of our manuscript. 10. If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. Response: We thank the editor for the suggestions. All suggested references were considered carefully and have been added with caution. Please see our responses to the reviewers’ comments below: Review 1: Introduction Nevertheless, compared to the earlier Delta variant, it has been associated with higher serum creatinine levels on admission to hospital, denoting greater renal impact [8] A single-centre study revealed a three-fold higher prevalence of AKI among intensive care unit (ICU) patients infected with the Omicron versus the Delta variant. However, the study was limited to 65 patients from a single centre who stayed in the ICU [14] • The authors used two references that reported a high prevalence of AKI in patients in the Omicron group and developed their research hypothesis based on these references We are not certain that all studies have reported this result, which seems to contradict the trend towards a reduction in the severity of COVID-19 over time since the appearance of COVID-19 corresponding to viral mutations, improved management with, for example, the use of corticosteroids, and the positive impact of vaccination. The authors could use the reference below (Nlandu, Y., Makulo, J. R., Essig, M., Sumaili, E., Lumaka, A., Engole, Y., … Nseka, N. (2023). Factors associated with acute kidney injury (AKI) and mortality in COVID-19 patients in a Sub-Saharan African intensive care unit: a single-center prospective study. Renal Failure, 45(2). https://doi.org/10.1080/0886022X.2023.2263583) where the authors reported a significantly higher prevalence of AKI-3 requiring dialysis during the first wave compared with others, in particular the 4th wave which corresponds to the omicron period. This could highlight the difference in the results of the various studies limited by their monocentric nature and the small size of their sample. This could further justify their study. Response: We thank the reviewer for suggesting the literature, we have read the recommended paper and decided to include this reference. This reference was added to the introduction section. Methods "Pre-Omicron" for admissions before December 1, 2021, and "Omicron" for admissions after January 1, 2022. These dates were chosen as they reflect the point at which the Omicron variant frequency reached 90% in the countries included in this study. • Failure to specify the viral variant by genetic sequencing could introduce a bias in the selection of patients and therefore in the interpretation of results, particularly in the context of low-income countries where, in the absence of vaccination, two variants of concern may be found concomitantly during the same period. The 90% threshold does not exclude the residual risk of recording a greater number of patients with a variant other than omicron. The authors should emphasize this within the limits of their study. Response: We thank the reviewer for pointing out this limitation. We had added this limitation in our discussion. There were no clinical flags in the datasets that identified specific variants, it was not feasible to discriminate patients infected with the Omicron variant from pre-Omicron variants in December 2021 thus these data were excluded • This is not enough to exclude patients with other variants. Response: We thank the reviewer for pointing this out. We acknowledge that our dataset does not include clinical or genomic markers to support the identification of specific variants. As such, we could not reliably differentiate infections caused by the Omicron variant from those caused by earlier variants, particularly during months identified by the WHO as periods of variant transition. To minimise potential sources of bias, we therefore excluded data from patients admitted in December 2021. This limitation has been acknowledged in the discussion part of the manuscript. Discussion The Chinese study reported one AKI patient for Omicron hospitalized patients and no AKI patient was recorded for Delta patients [8] • This study was used to justify the possible high prevalence of renal failure in the context of Omicron in the “introduction” section of the manuscript and in the “discussion” section its interpretation changes towards a low prevalence of AKI. We feel that it should not be used in the introduction as it has not reported a trend towards a high prevalence of AKI. Response: We thank the reviewer for the suggestion. We have removed this reference in the introduction. Few studies have explored the risk factors associated with AKI development and COVID-19 • I'm not sure that this sentence is correct, given the number of studies on COVID-19 that we currently have. Response: We thank the reviewer for pointing this out. We have revised the manuscript to more accurately reflect the current body of evidence. Reviewer 2: The authors describe results of a paper investigating differences in factors related to AKI among hospitalized patients with COVID-19 during and before the Omicron variant surges using a large dataset from multiple countries. I have the following comments/suggestions: Methods: What were the variables of interest that were imputed or excluded due to >20% missingness? Response: We appreciate the reviewer's attention to this methodological detail. The list of variables imputed and the percentage of missingness can be found in Supplementary Figure 1. The list of variables imputed includes hypertension, Systolic Blood Pressure, liver disease, hemoglobin, potassium, sodium, white blood cell count, platelet count, mechanical ventilation, antibiotics, vasopressors, chronic pulmonary diseases, chronic kidney disease, chronic cardiac disease and diabetes. Variable of interests excluded due to >20% of missingness was bicarbonate. We have added this information in the results section. Methods: What was the https://doi.org/10.1371/journal.pone.0336843.r002
8 Oct 2025 Decision Letter - Vipa Thanachartwet, Editor Dear Dr. Pole, 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. We appreciate your efforts for the study and the authors have made a careful revision to the manuscript. However, there are some minor points raised by the reviewer#1’s. Please carefully respond to the reviewer comments and suggestions. Please submit your revised manuscript by Nov 22 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. 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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. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author Reviewer #1: (No Response) Reviewer #2: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions??> Reviewer #1: Yes Reviewer #2: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? -->?> Reviewer #1: Yes Reviewer #2: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available??> The PLOS Data policy Reviewer #1: Yes Reviewer #2: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English??> Reviewer #1: Yes Reviewer #2: Yes ****** Reviewer #1: Firstly, I would like to thank the editor and authors for giving me the opportunity to review the manuscript. Below is our only comment regarding the latest version submitted. Introduction section A single-centre study revealed a three-fold higher prevalence of AKI among intensive care unit (ICU) patients infected with the Omicron versus the Delta variant. Another study identified significant higher prevalence of AKI in the 4th wave which corresponds to the Omicron period [13]. I would like to thank the authors for taking our suggestions into account and adding the recommended reference. However, they should amend the text to state that, in this study, the prevalence of AKI during the fourth wave of the pandemic was lower than in previous waves. Reviewer #2: (No Response) ****** 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 ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment 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. Registration is free. 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 PLOS at figures@plos.org Attachments Attachment Submitted filename: comments for PlosOne.docx https://doi.org/10.1371/journal.pone.0336843.r003
Revision 2
12 Oct 2025 Author Response Please see our responses to reviewer 1’s comment: Review 1 Comment: Reviewer #1: Firstly, I would like to thank the editor and authors for giving me the opportunity to review the manuscript. Below is our only comment regarding the latest version submitted. Introduction section A single-centre study revealed a three-fold higher prevalence of AKI among intensive care unit (ICU) patients infected with the Omicron versus the Delta variant. Another study identified significant higher prevalence of AKI in the 4th wave which corresponds to the Omicron period [13]. I would like to thank the authors for taking our suggestions into account and adding the recommended reference. However, they should amend the text to state that, in this study, the prevalence of AKI during the fourth wave of the pandemic was lower than in previous waves. Response: We thank the reviewer for pointing this out. We have amended the introduction to accurately reflect the referenced study. See the amended part below: “Another study identified significant higher prevalence of AKI in the 4th wave which corresponds to the Omicron period compared to the 3rd wave [13]. In this study, the 4th wave AKI prevalence was lower compared to the first and second wave which corresponds to the beginning of COVID [13] .” https://doi.org/10.1371/journal.pone.0336843.r004
2 Nov 2025 Decision Letter - Vipa Thanachartwet, Editor Omicron Surge Impact on Acute Kidney Injury in ICU Patients: A Study Using the ISARIC COVID-19 Database PONE-D-25-17813R2 Dear Dr. Pole, 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. An invoice will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager® and clicking the ‘Update My Information' link at the top of the page. For questions related to billing, please contact billing support . If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Vipa Thanachartwet, M.D. Academic Editor PLOS ONE Additional Editor Comments (optional): All comments have been addressed. Reviewers' comments: Reviewer's Responses to Questions Comments to the Author Reviewer #1: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions??> Reviewer #1: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? -->?> Reviewer #1: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available??> The PLOS Data policy Reviewer #1: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English??> Reviewer #1: Yes ****** Reviewer #1: I would like to thank the editor and authors for the opportunity to review this very interesting manuscript on the Omicron Impact on Acute Kidney Injury in ICU Patients. All comments have been addressed, so the manuscript can now be accepted for publication. ****** 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 ******** Attachments Attachment Submitted filename: AKI COVID omicron Plos one Round 2.docx https://doi.org/10.1371/journal.pone.0336843.r005
Formally Accepted
Acceptance Letter - Vipa Thanachartwet, Editor PONE-D-25-17813R2 PLOS ONE Dear Dr. Pole, I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now being handed over to our production team. At this stage, our production department will prepare your paper for publication. This includes ensuring the following: * All references, tables, and figures are properly cited * All relevant supporting information is included in the manuscript submission, * There are no issues that prevent the paper from being properly typeset You will receive further instructions from the production team, including instructions on how to review your proof when it is ready. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few days to review your paper and let you know the next and final steps. Lastly, if your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. You will receive an invoice from PLOS for your publication fee after your manuscript has reached the completed accept phase. If you receive an email requesting payment before acceptance or for any other service, this may be a phishing scheme. Learn how to identify phishing emails and protect your accounts at https://explore.plos.org/phishing. If we can help with anything else, please email us at customercare@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Professor Vipa Thanachartwet Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0336843.r006

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