The Food and Drug Administration is expected to allow giving Covid-19 vaccine boosters that are a different vaccine type from the one used in the initial doses, two sources familiar with the matter said.
The sources confirmed reporting by The New York Times, which on Monday reported that the FDA was planning the move.
The approach is sometimes called “mix and match.” A National Institutes of Health study found the approach to be safe and effective.
One of the sources told NBC News on Tuesday that an announcement could come as soon as Wednesday.
The source said the process needs to move forward with urgency to give doctors flexibility, and also because some people have already started using boosters different that the initial round of vaccinations.
The Times reported that the government would not recommend one type over another, and could still say that it is preferable to keep the booster the same as the first vaccinations.
So far the FDA has authorized the Pfizer-BioNTech vaccine for boosters, to be given at least six months after the initial series. But an FDA advisory panel last week voted to recommend emergency use authorization for Johnson & Johnson and Moderna booster shots.
The NIH study about mixing and matching vaccine boosters found that people who received the Johnson & Johnson vaccine produced stronger antibody levels after they got booster shots made by Moderna or Pfizer, compared to boosters from Johnson & Johnson.
Those who were originally vaccinated with the Pfizer or Moderna vaccines and received either company’s booster shot produced similarly strong immune responses, the researchers found.
Dr. Ashish Jha, dean of the Brown University School of Public Health, told NBC’s “TODAY” on Tuesday that reports the FDA could allow a mix-and-match approach was good news.
“Clinically, all the data says that mixing and matching is just fine, there’s no downside,” Jha said. He also said it could help in logistics, because people wouldn’t have to stick to the same type of shot.
Phil Helsel contributed.