COVID-19 vaccines still offer strong protection against severe illness and death, but Moderna and Pfizer are testing combination shots as a possible new kind of booster.
- COVID-19 vaccinations are at a critical juncture as companies test whether new approaches like combination shots or nasal drops can keep up with a mutating coronavirus — even though it’s not clear if changes are needed.
Despite success in preventing serious illness and death, there’s growing pressure to develop vaccines better at fending off milder infections, too — as well as options to counter scary variants. Updating the vaccine recipe to match the latest variants is risky, because the next mutant could be completely unrelated. So companies are taking a cue from the flu vaccine, which offers protection against three or four different strains in one shot every year.
After that first booster, CDC data suggests an additional dose offers most people an incremental, temporary benefit. But some people — those with severely weakened immune systems — need more doses up-front for a better chance at protection. “When I think about what would make me get a second booster, I actually would want to prevent infection,” said Dr. Grace Lee of Stanford University, who chairs CDC’s immunization advisory committee. “I think we need to do better.”