WASHINGTON (AP) — The U.S. Food and Drug Administration is wrestling with whether and when to offer a booster of the single-dose Johnson & Johnson COVID-19 vaccine — at six months or as early as two months. And a new study raises the prospect that using a different vaccine might give a better boost.
In a review posted online Wednesday, FDA scientists didn’t reach a firm conclusion about whether there’s enough evidence for J&J boosters, citing shortcomings with the company’s data and little information on protection against the extra-contagious delta variant of the coronavirus.
The review comes ahead of meetings Thursday and Friday, when an FDA advisory panel will recommend whether to back booster doses of both the J&J and Moderna vaccines. That’s one step in the government’s vaccine review process. Next week, the FDA will make a final decision on authorizing those boosters, and then the U.S. Centers for Disease Control and Prevention will debate who should actually get them.
Adding to the complexity is whether it’s OK to use a booster that’s a different brand than someone’s initial shots. Preliminary results of a U.S. government study suggest that mixing and matching boosters will work at least as well — and maybe far better for recipients of J&J’s vaccine. Those people had a stronger immune response if they got either a Moderna or Pfizer shot as their booster than if they received another dose of the J&J vaccine, according to results posted online Wednesday. A mix-and-match approach is also up for discussion by the FDA panel this week.
Health authorities contend that all of the vaccines used in the U.S. continue to provide strong protection against severe disease or death from COVID-19. However, amid signs that protection against milder infections may be waning, the government has already cleared booster doses of the Pfizer vaccine for certain people starting at six months after their last shot.
Aiming for uniform recommendations, Moderna likewise has asked the FDA to clear its booster dose at six months. But J&J complicated the agency’s decision by proposing a second shot over a range of two to six months.