US expected to authorize mix-and-match COVID booster shots

Virus Outbreak Boosters

WASHINGTON (AP) — Federal regulators are expected to authorize the mixing and matching of COVID-19 booster doses this week in an effort to provide flexibility as the campaign for extra shots expands.

The upcoming announcement by the Food and Drug Administration is likely to come along with authorization for boosters of the Moderna and Johnson & Johnson shots and follows the OK for a third dose for the Pfizer vaccine for many Americans last month. The move was previewed Tuesday by a U.S. health official familiar with the matter who was not authorized to speak publicly ahead of the announcement.

The FDA was expected to say that using the same brand for a booster was still preferable, especially for the mRNA vaccines from Pfizer and Moderna that have proved most effective against the coronavirus. The agency was still finalizing guidance for the single-shot J&J vaccine.

Preliminary results from a government study of different booster combinations found an extra dose of any type revs up levels of virus-fighting antibodies regardless of the b