Novavax COVID-19 Vaccine Becomes br 5th to Reach Phase 3 Trial in the US.br On Monday, Novavax announced the beginning br of its Phase 3 trial for its vaccine candidate, br named NVX-CoV2373, in the U.S. and Mexico.br This trial is a critical step in building the global portfolio of safe and effective vaccines to protect the world's population, Novavax President and CEO Stanley C. Erck, via news release.br The trial will evaluate safety, efficacy br and immune response in up tobr 30,000 people aged 18 and over.br The company also aims for at least br 25 of participants to be age 65 br or older and at least 15 to be Black.