The risk of symptomatic infection during a second COVID-19 wave, in SARS-CoV-2 seropositive individuals.

We analyzed 221 COVID-19 cases identified between June 2020 and January 2021 in 6,074 individuals screened for IgG antibodies in May 2020, representing 77% of residents of five Italian municipalities. The adjusted relative risk of developing symptomatic infection in SARS-COV-2 seropositive participants was 0.055 (95%CI: 0.014 - 0.220).