In the race to develop a combined vaccine, Novavax is ahead. But it’s not only because the company is the first to launch a clinical trial; it’s because the two key products that make up this combined vaccine candidate already have been through extensive testing. Novavax’s candidate involves a combination of its coronavirus vaccine and flu vaccine candidates.

The coronavirus candidate showed efficacy of more than 90% against mild, moderate, and severe disease. And it “demonstrated” 100% efficacy against moderate and severe disease. That’s in a phase 3 trial conducted in the U.S. and Mexico.

NanoFlu — the flu candidate — met all primary endpoints in a phase 3 clinical trial in the spring of 2020. This means it produced an immune response that wasn’t inferior to an already approved flu vaccine. It also beat secondary goals by producing higher immune responses to various flu strains than the approved vaccine. Novavax tested the candidate in adults ages 65 and older.

Novavax is heading into trials with two major components in this combined vaccine, where each has shown it’s safe and efficacious. That’s a big plus and something Moderna and Pfizer don’t have.