Reinfection with Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) among healthcare workers in India

Mukherjee et al., International Journal of Infectious Diseases, doi:10.1016/j.ijid.2026.109249, Nov 2026

Ivermectin for COVID-19

4th treatment shown to reduce risk in August 2020, now with p < 0.0000000001 from 106 studies, recognized in 24 countries.

No treatment is 100% effective.
Protocols combine treatments.

Prospective study of 1,331 healthcare workers in India showing SARS-CoV-2 reinfection incidence of 9.7 per 1,000 individuals (2.97 per 100,000 person-days) during the Omicron-dominant period. 52 participants used HCQ or ivermectin prophylaxis however authors do not report results for treated/untreated patients.
Study covers ivermectin and HCQ.
Mukherjee et al., 13 Nov 2026, retrospective, India, peer-reviewed, 38 authors, study period December 2021 - March 2023. Contact: tanu.anand@icmr.gov.in.
DOI record: { "DOI": "10.1016/j.ijid.2026.109249", "ISSN": [ "1201-9712" ], "URL": "http://dx.doi.org/10.1016/j.ijid.2026.109249", "alternative-id": [ "S1201971226008842" ], "article-number": "109249", "assertion": [ { "label": "This article is maintained by", "name": "publisher", "value": "Elsevier" }, { "label": "Article Title", "name": "articletitle", "value": "Reinfection with Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) among healthcare workers in India" }, { "label": "Journal Title", "name": "journaltitle", "value": "International Journal of Infectious Diseases" }, { "label": "CrossRef DOI link to publisher maintained version", "name": "articlelink", "value": "https://doi.org/10.1016/j.ijid.2026.109249" }, { "label": "Content Type", "name": "content_type", "value": "article" }, { "label": "Copyright", "name": "copyright", "value": "© 2026 Published by Elsevier Ltd on behalf of International Society for Infectious Diseases." } ], "author": [ { "affiliation": [], "family": "Mukherjee", "given": "Aparna", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "first" }, { "ORCID": "https://orcid.org/0000-0003-2911-2332", "affiliation": [], "authenticated-orcid": false, "family": "Anand", "given": "Tanu", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Singh", "given": "Kh Jitenkumar", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Sharma", "given": "Lokesh", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Velamuri", "given": "Poonam Sharma", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Satija", "given": "Aanchal", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Birhman", "given": "Nikita", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Josten", "given": "Kripa", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Yadav", "given": "Pragya", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Sahay", "given": "Rima R", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Shete", "given": "Anita M.", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Kumar", "given": "Gunjan", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "J", "given": "Madhumathi", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Kannauje", "given": "Pankaj Kumar", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Baruah", "given": "Tridip Dutta", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Malhotra", "given": "Bharti", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Choudhary", "given": "Rashmi", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Nanjegowda", "given": "Raveesh Bevinahalli", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Nageshappa", "given": "Savitha", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Manjegowda", "given": "Srikanta", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Kalyanaraman", "given": "Shantaraman", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Ruban", "given": "Charles Pon", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Desai", "given": "Hetal Tejas", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Panchal", "given": "Silver", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Singh", "given": "Uma Shanker", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Mandhan", "given": "Ramesh Kumar", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Kharb", "given": "Simmi", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Dasgupta", "given": "Nivedita", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Choudhury", "given": "Biswadeep", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Singh", "given": "Haobijam Nirendrakumar", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Nandeibam", "given": "Alfred Rozer", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Raina", "given": "Sunil Kumar", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Chauhan", "given": "Raman", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Praharaj", "given": "Ira", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Mohapatra", "given": "Sumegha", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Saxena", "given": "Abhishweta", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Thakur", "given": "Akhilesh", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" }, { "affiliation": [], "family": "Malik", "given": "Deepak", "role": [ { "role": "author", "vocabulary": "crossref" } ], "sequence": "additional" } ], "container-title": "International Journal of Infectious Diseases", "container-title-short": "International Journal of Infectious Diseases", "content-domain": { "crossmark-restriction": true, "domain": [ "clinicalkey.com", "clinicalkey.com.au", "clinicalkey.es", "clinicalkey.fr", "clinicalkey.jp", "ijidonline.com", "elsevier.com", "sciencedirect.com" ] }, "created": { "date-parts": [ [ 2026, 11, 14 ] ], "date-time": "2026-11-14T00:41:53Z", "timestamp": 1794616913000 }, "deposited": { "date-parts": [ [ 2026, 11, 14 ] ], "date-time": "2026-11-14T00:41:55Z", "timestamp": 1794616915000 }, "indexed": { "date-parts": [ [ 2026, 11, 14 ] ], "date-time": "2026-11-14T01:22:26Z", "timestamp": 1794619346593, "version": "4.9.1" }, "is-referenced-by-count": 0, "issued": { "date-parts": [ [ 2026, 11 ] ] }, "language": "en", "license": [ { "URL": "https://www.elsevier.com/tdm/userlicense/1.0/", "content-version": "tdm", "delay-in-days": 0, "start": { "date-parts": [ [ 2026, 11, 1 ] ], "date-time": "2026-11-01T00:00:00Z", "timestamp": 1793491200000 } }, { "URL": "https://www.elsevier.com/legal/tdmrep-license", "content-version": "tdm", "delay-in-days": 0, "start": { "date-parts": [ [ 2026, 11, 1 ] ], "date-time": "2026-11-01T00:00:00Z", "timestamp": 1793491200000 } }, { "URL": "http://creativecommons.org/licenses/by-nc-nd/4.0/", "content-version": "vor", "delay-in-days": 9, "start": { "date-parts": [ [ 2026, 11, 10 ] ], "date-time": "2026-11-10T00:00:00Z", "timestamp": 1794268800000 } } ], "link": [ { "URL": "https://api.elsevier.com/content/article/PII:S1201971226008842?httpAccept=text/xml", "content-type": "text/xml", "content-version": "vor", "intended-application": "text-mining" }, { "URL": "https://api.elsevier.com/content/article/PII:S1201971226008842?httpAccept=text/plain", "content-type": "text/plain", "content-version": "vor", "intended-application": "text-mining" } ], "member": "78", "original-title": [], "page": "109249", "prefix": "10.1016", "published": { "date-parts": [ [ 2026, 11 ] ] }, "published-print": { "date-parts": [ [ 2026, 11 ] ] }, "publisher": "Elsevier BV", "reference": [ { "key": "10.1016/j.ijid.2026.109249_bib0001", "series-title": "WHO chief declares end to COVID-19 as a global health emergency [Internet]", "year": "2023" }, { "article-title": "Research progress in the reinfection of novel coronavirus", "author": "Xuechun", "first-page": "3229", "journal-title": "Chin. Med. J.", "key": "10.1016/j.ijid.2026.109249_bib0002", "volume": "102", "year": "2022" }, { "DOI": "10.1021/acs.jcim.1c01451", "article-title": "Omicron Variant (B.1.1.529): Infectivity, Vaccine Breakthrough, and Antibody Resistance", "author": "Chen", "doi-asserted-by": "crossref", "first-page": "412", "journal-title": "J. Chem. Inf. Model.", "key": "10.1016/j.ijid.2026.109249_bib0003", "volume": "62", "year": "2022" }, { "DOI": "10.1038/s41586-022-04980-y", "article-title": "BA.2.12.1, BA.4 and BA.5 escape antibodies elicited by Omicron infection", "author": "Cao", "doi-asserted-by": "crossref", "first-page": "593", "journal-title": "Nature", "key": "10.1016/j.ijid.2026.109249_bib0004", "volume": "608", "year": "2022" }, { "DOI": "10.1093/cid/ciaa1846", "article-title": "Assessment of the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection in an intense reexposure setting[J]", "author": "Abu-Raddad", "doi-asserted-by": "crossref", "first-page": "e1830", "issue": "7", "journal-title": "Clin Infect Dis", "key": "10.1016/j.ijid.2026.109249_bib0005", "volume": "73", "year": "2021" }, { "DOI": "10.1111/eci.13845", "article-title": "Risk of reinfection and disease after SARS-CoV-2 primary infection: Meta-analysis", "author": "Flacco", "doi-asserted-by": "crossref", "journal-title": "Eur. J. Clin. Investig.", "key": "10.1016/j.ijid.2026.109249_bib0006", "volume": "52", "year": "2022" }, { "article-title": "COVID-19 infection, and reinfection, and vaccine effectiveness against symptomatic infection among health care workers in the setting of omicron variant transmission in New Delhi, India", "author": "Malhotra", "issue": "100023", "journal-title": "The Lancet Regional Health Southeast Asia", "key": "10.1016/j.ijid.2026.109249_bib0007", "volume": "3", "year": "2022" }, { "DOI": "10.3390/v15040967", "article-title": "SARS-CoV-2 Reinfection and Severity of the Disease: A Systematic Review and Meta-Analysis", "author": "Nguyen", "doi-asserted-by": "crossref", "first-page": "967", "issue": "4", "journal-title": "Viruses", "key": "10.1016/j.ijid.2026.109249_bib0008", "volume": "15", "year": "2023" }, { "DOI": "10.1017/S0950268821000662", "article-title": "SARS-CoV-2 re-infection: development of an epidemiological definition from India", "author": "Mukherjee", "doi-asserted-by": "crossref", "journal-title": "Epidemiology and Infection", "key": "10.1016/j.ijid.2026.109249_bib0009", "year": "2021" }, { "key": "10.1016/j.ijid.2026.109249_bib0010", "unstructured": "CDC. Common Investigation Protocol for Investigating Suspected SARS-CoV-2 Reinfection [Internet] 2020 [Accessed on 5th May, 2021]. Available from: https://www.cdc.gov/coronavirus/2019-ncov/php/reinfection.html" }, { "key": "10.1016/j.ijid.2026.109249_bib0012", "series-title": "Coronavirus disease (COVID-19): epidemiology update and reinfection evidence", "year": "2023" }, { "DOI": "10.1038/s41586-022-04411-y", "article-title": "Rapid epidemic expansion of the SARS-CoV-2 Omicron variant in southern Africa", "author": "Viana", "doi-asserted-by": "crossref", "first-page": "679", "issue": "7902", "journal-title": "Nature", "key": "10.1016/j.ijid.2026.109249_bib0013", "volume": "603", "year": "2022" }, { "key": "10.1016/j.ijid.2026.109249_bib0014", "series-title": "SARS-CoV-2 variants of concern and variants under investigation in England: technical briefing", "year": "2022" }, { "article-title": "Clinical characterization and genomic analysis of SARS-CoV-2 reinfection cases in India", "author": "Gupta", "first-page": "3226", "issue": "7", "journal-title": "Journal of Medical Virology", "key": "10.1016/j.ijid.2026.109249_bib0015", "volume": "94", "year": "2022" }, { "DOI": "10.1126/science.abj9932", "article-title": "Genomic characterization and epidemiology of an emerging SARS-CoV-2 variant in Delhi, India", "author": "Dhar", "doi-asserted-by": "crossref", "first-page": "995", "issue": "6570", "journal-title": "Science", "key": "10.1016/j.ijid.2026.109249_bib0016", "volume": "374", "year": "2021" }, { "DOI": "10.1038/s41586-022-04411-y", "article-title": "Rapid epidemic expansion of the SARS-CoV-2 Omicron variant in southern Africa", "author": "Viana", "doi-asserted-by": "crossref", "first-page": "679", "journal-title": "Nature", "key": "10.1016/j.ijid.2026.109249_bib0017", "volume": "603", "year": "2022" }, { "DOI": "10.1126/science.abq1841", "article-title": "Immune boosting by B.1.1.529 (Omicron) depends on previous SARS-CoV-2 exposure", "author": "Reynolds", "doi-asserted-by": "crossref", "first-page": "eabq1841", "journal-title": "Science", "key": "10.1016/j.ijid.2026.109249_bib0018", "volume": "377", "year": "2022" }, { "DOI": "10.1056/NEJMoa2203965", "article-title": "Effects of previous infection and vaccination on symptomatic Omicron infections", "author": "Altarawneh", "doi-asserted-by": "crossref", "first-page": "21", "journal-title": "New England Journal of Medicine", "key": "10.1016/j.ijid.2026.109249_bib0019", "volume": "387", "year": "2022" }, { "article-title": "Prevalence of SARS-CoV-2 reinfection among healthcare workers during the Omicron surge", "author": "Mani", "first-page": "e1072", "issue": "3", "journal-title": "Clin Infect Dis", "key": "10.1016/j.ijid.2026.109249_bib0020", "volume": "76", "year": "2023" }, { "DOI": "10.1016/S2468-2667(20)30164-X", "article-title": "Risk of COVID-19 among frontline healthcare workers and the general community", "author": "Nguyen", "doi-asserted-by": "crossref", "first-page": "e475", "issue": "9", "journal-title": "Lancet Public Health", "key": "10.1016/j.ijid.2026.109249_bib0021", "volume": "5", "year": "2020" }, { "DOI": "10.1093/aje/kwaa191", "article-title": "COVID-19 in healthcare workers: a living systematic review and meta-analysis of prevalence, risk factors, clinical characteristics, and outcomes", "author": "Gómez-Ochoa", "doi-asserted-by": "crossref", "first-page": "161", "issue": "1", "journal-title": "Am J Epidemiol", "key": "10.1016/j.ijid.2026.109249_bib0022", "volume": "190", "year": "2021" }, { "DOI": "10.1016/S0140-6736(22)00462-7", "article-title": "Comparative analysis of the risks of hospitalization and death associated with SARS-CoV-2 Omicron and Delta variants in England", "author": "Nyberg", "doi-asserted-by": "crossref", "first-page": "1303", "issue": "10332", "journal-title": "Lancet", "key": "10.1016/j.ijid.2026.109249_bib0023", "volume": "399", "year": "2022" }, { "DOI": "10.1016/S0140-6736(22)00017-4", "article-title": "Early assessment of the clinical severity of the SARS-CoV-2 Omicron variant in South Africa", "author": "Wolter", "doi-asserted-by": "crossref", "first-page": "437", "issue": "10323", "journal-title": "Lancet", "key": "10.1016/j.ijid.2026.109249_bib0024", "volume": "399", "year": "2022" }, { "DOI": "10.1056/NEJMoa2118691", "article-title": "Protection against SARS-CoV-2 after COVID-19 vaccination and previous infection", "author": "Hall", "doi-asserted-by": "crossref", "first-page": "1207", "issue": "13", "journal-title": "N Engl J Med", "key": "10.1016/j.ijid.2026.109249_bib0025", "volume": "386", "year": "2022" }, { "DOI": "10.1056/NEJMoa2119451", "article-title": "COVID-19 vaccine effectiveness against the Omicron variant", "author": "Andrews", "doi-asserted-by": "crossref", "first-page": "1532", "issue": "16", "journal-title": "N Engl J Med", "key": "10.1016/j.ijid.2026.109249_bib0026", "volume": "386", "year": "2022" } ], "reference-count": 25, "references-count": 25, "relation": {}, "resource": { "primary": { "URL": "https://linkinghub.elsevier.com/retrieve/pii/S1201971226008842" } }, "score": 1, "short-title": [], "source": "Crossref", "subject": [], "subtitle": [], "title": "Reinfection with Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) among healthcare workers in India", "type": "journal-article", "update-policy": "https://doi.org/10.1016/elsevier_cm_policy" }