June 1, 2021

Prior COVID-19 Protects against Reinfection, Even in the Absence of Detectable Antibodies

Category: Article Summary

Topic: Vaccines and Immunity

Keywords (Tags): immunity, re-infection

• Risk of SARS-CoV-2 infection in the UK between August 2020 and January 2021 was 80% lower among individuals with lab-confirmed infection but later testing antibody-negative (i.e. RNA-positive antibody-negative) compared to individuals who did not have infection (no test or RNA-negative and antibody-negative) during March to July 2020, according to an analysis of datasets obtained from 4 UK laboratories. Only 2 reinfections (>90 days after initial infection) occurred among 224 RNA-positive antibody-negative individuals (0.9%) compared to 2,054 second-wave infections in the 47,139 patients with no prior infection (4.4%). Risk of SARS-CoV-2 infection in RNA-positive antibody-negative individuals was similar to a subset of 2,087 patients who were RNA-positive and antibody-positive. As the study is based on laboratory datasets, the authors caution that testing may have been event-driven compared with datasets from routine screening.

Breathnach et al. (May 2021). Prior COVID-19 Protects against Reinfection, Even in the Absence of Detectable Antibodies. Journal of Infection. https://doi.org/10.1016/j.jinf.2021.05.024