The National Institutes of Health released a study Wednesday indicating that “mixing and matching” COVID-19 vaccines is safe and effective and that recipients of the Johnson & Johnson one-shot regiment are better off getting a different booster.

NBC News explains that researchers, “found that people who received the Johnson & Johnson vaccine produced stronger antibody levels after receiving a booster shot made by Moderna or Pfizer, compared to a booster from Johnson & Johnson.”

Those who initially received the Johnson & Johnson jab were particularly well-served by a Moderna booster, which increased their antibody levels 76-fold within 15 days. A Pfizer booster raised antibody levels in Johnson & Johnson recipients 35-fold.

The New York Times explains:

That finding, along with a mixed review of Johnson & Johnson’s booster data from the Food and Drug Administration released earlier in the day, could lead to a heated debate about whether and how to offer additional shots to the 15 million Americans who have received the single-dose vaccine.

NPR adds:

People who got the Moderna vaccine for their original shots and Moderna again for their booster appear to have gotten the best immune response, followed by those who got Pfizer boosted by Moderna and then Moderna boosted by Pfizer — although the increase in immune response with the mRNA vaccines was probably too small to really make a difference in protection in most groups.

The authors of the study believe all mix and match combinations are worth considering. “[Our] data suggest that if a vaccine is approved or authorized as a booster, an immune response will be generated regardless of the primary Covid-19 vaccination regimen,” notes the conclusion of the study, which is yet to be peer-reviewed.

Bloomberg reports, “mixing-and-matching could make it easier for officials to roll out boosters more broadly, as people getting boosters could receive any Covid vaccine on hand at their pharmacy and wouldn’t have to seek out the specific shot they had gotten previously.”

The Food and Drug Administration will consider the study later this week as it meets to determine if booster shots of the Moderna and Johnson & Johnson vaccines should be authorized.