Reinfection after Natural Infection with SARS-CoV-2: A Cohort Study
4 Pages Posted: 19 Aug 2021
Date Written: July 8, 2021
Background: A total of 5000 participants were tested for SARS-CoV-2 antibodies in a serosurvey in a twin township of Maharashtra, India in October 2020. A total of 1,726 were found to have IgG antibodies against this novel coronavirus. We followed them up after 8 months to ascertain reinfections.
Methods: An attempt was made to contact all the 1,726 participants who had tested positive for IgG antibodies against the novel coronavirus. Out of these 1081 could be contacted on telephone. Reinfection was identified by asking for symptoms like fever, cough, body ache, loss of smell and history of contact with positive patient and being found positive on being tested by RT-PCR.
Results: Out of the 1,726 participants, 1,081(62.6%) could be contacted. Only 13 (1.2%) got re-infected by covid-19. All the cases were mild and recovered uneventfully.
Conclusion: The study suggests that re-infection after recovering from natural infection was very low during 8 months of follow up. The findings could guide rational vaccine policies particularly as there is crises of supply in most developing countries. Those who have recovered may not be included in mass vaccination campaigns on priority.
Note: Funding: The earlier study of which the present study is a follow up was funded by the Pimpri-Chinchwad Municipal Corporation.
Declaration of Interests: None of the investigators of the present follow up study are employed by the funding agency. None of the investigators have any conflict of interest. The sponsor did not have any role in data collection, analysis and report writing.
Ethics Approval Statement: The ethical approval for the study was given by the Institutional Review Board of Dr DY Patil Vidyapeeth (Deemed University), Pune, Maharashtra.
Keywords: SARS-CoV-2, reinfection, immunity
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