NIH Says ‘Mix and Match’ Approach Effective for COVID-19 Boosters

Researchers from the National Institutes of Health (NIH) have found that a “mix and match” approach using different COVID-19 booster vaccines is safe and effective.

The preliminary findings, released ahead of an FDA advisory committee meeting exploring the issue today and tomorrow, suggest that an extra shot of the Moderna or Pfizer/BioNTech jab induces greater immunity than another dose of the Johnson & Johnson (J&J) vaccine.

The 458-person phase 1/2 study assessed antibody responses at two weeks and four weeks following administration of a booster.

Individuals who received a two-dose Moderna or Pfizer/BioNTech primary series received either a Moderna, Pfizer/BioNTech or J&J booster, while those who received a single J&J shot were given an extra J&J, Moderna or Pfizer/BioNTech shot.

“A substantial increase in neutralizing antibody titers was observed in all study participants following booster vaccination irrespective of booster and primary vaccine series,” the researchers said.

An additional dose of the same vaccine as the primary series boosted antibody levels four- to 20-fold, while mixing and matching primary vaccines and booster doses boosted antibody levels six- to 76-fold.

But despite the NIH’s support for boosters, FDA officials appear less than enthused about authorizing more boosters, according to briefing documents released Tuesday. For example, the agency found that Moderna’s data didn’t show its messenger RNA-based booster increased protective antibodies enough to warrant approving the extra shot. (DID, Oct. 13).

Read the NIH’s study findings here: www.fdanews.com/2021101021264827v1full.pdf. ― Jason Scott