Durablity of response to COVID-19 mRNA-1273 vaccination

Editor's Note

This study led by the National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, finds that vaccinations with mRNA-1273 (Moderna) have the potential to provide durable humoral immunity.

This report describes immunogenicity data for mRNA-1273 at 119 days after the first vaccination and 90 days after the second vaccination in 34 adult participants in Moderna’s trial.

At a dose of 100-µg, the vaccine produced high levels of binding and neutralizing antibodies that declined slightly as expected but remained elevated in all participants 3 months after the booster vaccination. Neutralizing antibodies continued to be found in all participants at day 119.

During the trial, no serious adverse events were noted, no prespecified trial-halting rules were met, and no new adverse events related to the vaccine occurred after day 57.

Though the memory cellular response to mRNA-1273 is not yet defined, the vaccine elicited primary CD4 type 1 helper T-cell responses 43 days after the first vaccination, the researchers say, and studies of vaccine-induced B cells are ongoing.