Circulating SARS-CoV-2 Vaccine Antigen Detected in the Plasma of mRNA-1273 Vaccine Recipients

Clin Infect Dis. 2021 May 20;ciab465. doi: 10.1093/cid/ciab465. Online ahead of print.


SARS-CoV-2 proteins were measured in longitudinal plasma samples collected from 13 participants who received two doses of mRNA-1273 vaccine. 11 of 13 participants showed detectable levels of SARS-CoV-2 protein as early as day one after first vaccine injection. Clearance of detectable SARS-CoV-2 protein correlated with production of IgG and IgA.

Keywords: COVID-19; SARS-CoV-2 antigens; immune responses; mRNA vaccine; spike.