The Maryland-based late-stage biotechnology company said its Matrix-M adjuvant would be used with the vaccine candidate - NVX-CoV2373 - to enhance immune responses.
Adjuvants are mainly used to enable a vaccine to induce a strong immune response including a greater production of antibodies and longer-lasting protection against viral and bacterial infections.
Novavax said preliminary immunogenicity and safety results from the trial were expected in July.
It joins at least a dozen other drugmakers working on vaccines, antivirals and other treatments to help those infected with the fast-spreading respiratory virus, with some antivirals already being used in trials.
Highly anticipated data for a Gilead Sciences Inc experimental antiviral drug are expected later this month.
Analysts are also awaiting results in the near term for products already approved for other conditions from companies such as Roche Holding and Regeneron Pharmaceuticals Inc .
While experts estimate an approved vaccine could be at least a year away, progress toward treatments that benefit some COVID-19 patients could help investors gauge when the epidemic could come under control and some economic activity might resume.
Studies are also ongoing for hydroxychloroquine, a decades-old malaria drug that has been used by doctors for COVID-19, despite disagreements about its effectiveness.
More than 1.34 million people have been reported infected by the coronavirus across the world and 76,043 have died, according to a Reuters tally.