“…The National Blood Donor Seroprevalence (NBDS) study was a serial cross-sectional study conducted during 2020 and 2021. 30 , 31 , 32 , 33 The Repeat Donor Cohort (RDC) is a prospective cohort of 152,000 repeat blood donors from Vitalant (>65,000 donors) and American Red Cross (>77,000 donors), which are the 2 largest blood collection organizations in the U.S.…”