On Mar. 31, 2021, the National Institutes of Health (NIH) announced that an investigational vaccine designed to protect against the B.1.351 SARS-CoV-2 variant was administered as part of a new Phase 1 clinical trial evaluating the vaccine candidate’s safety and immunogenicity in adult volunteers.

The vaccine, known as mRNA-1273.351, was developed by the biotechnology company Moderna. The trial was led and funded by the National Institute of Allergy and Infectious Diseases and and enrolled approximately 210 healthy adult volunteers at four clinical research sites in the U.S.