May 4, 2021

SARS-CoV-2 antibody-positivity protects against reinfection for at least seven months with 95% efficacy

Category: Article Summary

Topic: Vaccines and Immunity

Keywords (Tags): antibodies, immunity, re-infection

• Incidence of SARS-CoV-2 infection was 95% lower among persons with prior SARS-CoV-2 infection, indicated by seropositivity, in a cohort study in Qatar. In the study, 129 of 43,044 seropositive persons (0.3%) followed for a median of 16 weeks had at least one positive PCR test supported by evidence of reinfection at least 14 days after their first antibody-positive test, corresponding to an estimated incidence of reinfection of 0.66 cases per 10,000 person weeks. By contrast, 3,185 of 149,923 (2.1%) persons seronegative at baseline followed for a median of 17 weeks had at least one positive PCR, corresponding to 14 cases per 10,000 person-weeks.

Abu-Raddad et al. (May 27, 2021). SARS-CoV-2 antibody-positivity protects against reinfection for at least seven months with 95% efficacy. EClinicalMedicine. https://doi.org/10.1016/j.eclinm.2021.100861