French company Valneva, meanwhile, is working on an inactivated vaccine using the whole virus that might have advantages over those already approved, Thomas Lingelbach, the company’s chief executive officer, says. Because it uses the complete virus, the Valneva vaccine enables the immune system to potentially form a response to all possible epitopes—a term for the portions of the virus’s proteins that the immune system can recognize. Valneva also combines the inactivated virus with an adjuvant, a chemical substance that boosts the body’s immune response. What’s more, Valneva has experience producing multivalent vaccines—those that incorporate multiple virus strains in a single shot—and it could potentially produce one for SARS-CoV-2 too.