Data from: SARS-CoV-2 antibody dynamics in blood donors and COVID-19 epidemiology in eight Brazilian state capitals

The COVID-19 situation in Brazil is complex due to large differences in
the shape and size of regional epidemics. Here we tested monthly blood
donation samples for IgG antibodies from March 2020 to March 2021 in eight
of Brazil’s most populous cities. The inferred attack rate of SARS-CoV-2
adjusted for seroreversion in December 2020, before the Gamma VOC was
dominant, ranged from 19.3% (95% CrI 17.5% - 21.2%) in Curitiba to 75.0%
(95% CrI 70.8% - 80.3%) in Manaus. Seroprevalence was consistently smaller
in women and donors older than 55 years. The age-specific infection
fatality rate (IFR) differed between cities and consistently increased
with age. The infection hospitalisation rate (IHR) increased significantly
during the Gamma-dominated second wave in Manaus, suggesting increased
morbidity of the Gamma VOC compared to previous variants circulating in
Manaus. The higher disease penetrance associated with the health system’s
collapse increased the overall IFR by a minimum factor of 2.91 (95% CrI
2.43 – 3.53). These results highlight the utility of blood donor
serosurveillance to track epidemic maturity and demonstrate demographic
and spatial heterogeneity in SARS-CoV-2 spread.