A European Union advisory committee endorsed extra shots of Pfizer Inc.’s Covid-19 vaccine for all adults, as well as extra doses of Moderna Inc.’s for those with severely weakened immune systems, Bloomberg reports.

Those ages 18 and older can get a third dose of the Pfizer vaccine, developed with BioNTech SE, at least six months after their second shot, the European Medicines Agency said in a statement Monday. For the immunocompromised, extra doses of Pfizer or Moderna can be given at least 28 days after the second.

The European Medicines Agency committee is following the U.S. and other countries with ample vaccine supplies in allocating doses or considering the move for booster shots. The U.S. Food and Drug Administration may soon authorize half-dose boosters of the Moderna vaccine, setting the stage to further widen the U.S. booster campaign after earlier authorization of the extra Pfizer-BioNTech dose.

Concern about withering Covid protection prompted Israel -- one of the first countries to start vaccinating its population -- to begin administering booster shots months ago.