(Bloomberg) -- The Food and Drug Administration is expected to decide as soon as Wednesday on a recommendation for Covid-19 boosters made by Pfizer Inc. and BioNTech SE, two people familiar with the matter said, the latest step in a process that could open the door to extra shots in the coming days.

The agency’s decision would tee up consideration by an advisory panel of the Centers for Disease Control and Prevention, which has scheduled a meeting for Wednesday and Thursday to discuss boosters.

On Friday, an FDA advisory panel rejected a call for boosters for all adults, instead deciding to urge them for a narrower group: people 65 and older, those at risk of severe Covid-19 and those at risk of occupational exposure. Those parameters could be tweaked by the FDA. 

President Joe Biden’s medical advisers in August called for boosters to begin this week. The first boosters will be authorized for people who received the Pfizer-BioNTech vaccine, while Moderna Inc. boosters remain under consideration by regulators. Separately, Johnson & Johnson said Tuesday that a second dose of its one-shot vaccine provided 100% protection against severe disease when given two months after the first inoculation.

The list of eligible people eventually could expand beyond what the panel recommended Friday and what the FDA may clear this week. 

“Certainly, I think there will be a decision in the coming weeks to extend boosters beyond the list that they approved on Friday,” Francis Collins, director of the National Institutes of Health, said on the CBS program “Face the Nation” on Sunday.

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