U.S. Makes Its Riskiest Bet Yet on a Coronavirus Vaccine

The U.S. government has tapped a sixth vaccine-maker to receive big federal bucks as the Trump administration races to approve a COVID-19 vaccine by the end of the year. But this latest vaccine candidate, from Maryland-based pharma Novavax, might be the riskiest yet.

Novavax has been in the pharmaceuticals business since 1987 but has yet to get a single vaccine past the U.S. Food and Drug Administration. And Novavax’s vaccine candidate itself is risky. It’s...