Jones JM, Stone M, Sulaeman H, et al. - Based on blood donations in the US from July 2020 through May 2021, trends in SARS-CoV-2 seroprevalence related to infection and vaccination were investigated in the US population.

• During July 2020 through May 2021, a repeated cross-sectional study was conducted each month, including 1,443,519 blood donation specimens from a catchment area representing 74% of the US population.

• There appeared an increase in estimated SARS-CoV-2 seroprevalence weighted for differences between the study sample and general population from 3.5% in July 2020 to 20.2% for infection-induced antibodies and 83.3% for combined infection- and vaccine-induced antibodies in May 2021.

• Differences in seroprevalence were identified by age, race and ethnicity, and geographic region of residence, but modification in these differences occurred over the course of the study.