FDA panel backs lower-dose Moderna COVID booster

U.S. health advisers said Thursday that some Americans who received Moderna’s COVID-19 vaccine should get a half-dose booster to bolster protection against the virus.

The panel of advisers to the Food and Drug Administration voted unanimously to recommend a booster shot for seniors, adults with other health problems, jobs or living situations that put them at increased risk for COVID-19.

As for the dose, initial Moderna vaccination consists of two 100-microgram shots. But Moderna says a single 50-microgram shot should be enough for a booster.

On Friday, advisers will recommend if and when to offer boosters to Johnson & Johnson vaccine recipients.

The FDA will use its advisers’ recommendations in making final decisions for boosters from both companies. Assuming a positive decision, there’s still another hurdle: Next week, a panel convened by the Centers for Disease Control and Prevention will offer more specifics on who should get one.

U.S. officials stress that the priority is to get shots to the 66 million unvaccinated Americans who are eligible for immunization.

"Facilitating higher primary coverage of the entire vaccine eligible population with the initial series of vaccination should still be a key priority," said FDA vaccine chief Dr. Peter Marks.

But Marks said it’s also become clear there is some waning of protection against milder infections with all three of the coronavirus vaccines used in the U.S.

Certain high-risk groups who got their initial Pfizer vaccinations at least six months ago are already rolling up their sleeves.