Immunogenicity Assessments
VIRUS
Day 0 (baseline) and day 35 serum samples were tested for neutralizing antibodies specific to SARS-CoV-2, measured with a validated microneutralization assay that defined titers as the inverse serum dilution that yielded 50% viral inhibition. The assay used wild-type virus strain SARS-CoV-2 hCoV-19/ Australia/VIC01/2020 (GenBank MT007544.1) (360biolabs)Prior exposure to SARS-CoV-2 was determined by the presence of serum antinucleoprotein antibodies (University of Washington, Seattle), using an anti–SARS-CoV-2 assay (Elecsys; F Hoffmann–La Roche Ltd),