May 28, 2021

Risk of Reinfection after Seroconversion to SARS-CoV-2: A Population-Based Propensity-Score Matched Cohort Study

Category: Article Summary

Topic: Vaccines and Immunity

Keywords (Tags): immunity

• Swiss adults who were seropositive for SARS-CoV-2 IgG antibodies were less likely to have a SARS-CoV-2 PCR positive test than propensity-score-matched seronegative adults in the 8 months following antibody measurements. Of the 498 seropositive individuals, only 5 (1%) retested positive (likely indicative of reinfection) after a mean follow-up of 36 weeks. In contrast, 154 of 996 (16%) matched seronegative individuals tested positive during a similar mean follow-up of 35 weeks. These findings suggest that seropositivity is associated with a 94% reduction in risk of retesting positive. The authors note that while testing rates were similar between seropositive and seronegative individuals, risk of detection may be underestimated among seropositive individuals if individuals with reinfection are less likely to be symptomatic. [EDITORIAL NOTE: This manuscript was summarized as a pre-print on March 22, 2020.]

Leidi et al. (May 27, 2021). Risk of Reinfection after Seroconversion to SARS-CoV-2: A Population-Based Propensity-Score Matched Cohort Study. Clinical Infectious Diseases. https://doi.org/10.1093/cid/ciab495