A federal advisory committee will decide Friday whether booster shots of COVID-19 vaccines are safe and effective against infection.

The Food and Drug Administration advisory committee will consider information from Pfizer and its German partner BioNTech in deciding whether to allow the companies to provide third vaccine doses to people 16 and older.

If the advisory committee does decide that third doses are safe and effective, it will be up to the Centers for Disease Control and Prevention (CDC) and its own advisory committee to decide who should receive the boosters and when.

Input from the panel and a separate committee of outside experts that advises the CDC will play a role in the FDA's decision on approving the additional shot. 

In a letter Thursday published on Pfizer's website, CEO Albert Bourla said both lab data and real-world evidence from Israel showed boosters can play an important role in addressing the pandemic.

"A booster of the same dose and the same vaccine can achieve this marked enhancement of protection," Bourla wrote.

In briefing information provided to the advisory committee — all experts in aspects of vaccine development and immunology — and posted online Wednesday, the FDA emphasized studies supporting the need for boosters aren't conclusive and weren't conducted in the United States, which may see different results than other countries.

"Overall, data indicate that currently US-licensed or authorized COVID-19 vaccines still afford protection against severe COVID-19 disease and death in the United States," the report said.

One possible outcome would be for the panel meeting on Friday to recommend booster shots for now to only certain groups, such as healthcare workers or people 65 and older, according to people familiar with the matter, The Wall Street Journal reported Thursday. 

The agencies are considering only the Pfizer-BioNTech vaccine, though they are expected to soon review the Moderna vaccine as well.

The Biden administration had targeted next week to start widely distributing the extra shots. The plan has drawn criticism, with some scientists saying the general population doesn't now need a booster shot, and two top US scientists who worked for the FDA having resigned over the booster plan. 

Others, including the director general of the World Health Organization, argue that Americans would benefit far more by getting initial shots to those unvaccinated around the world.

Meanwhile, President Joe Biden on Thursday accused several Republican governors of using their power to prevent their citizens from being protected from the spread of the coronavirus.

"The governors of Florida and Texas are doing everything they can to undermine the lifesaving requirements that I proposed," he said in remarks from the White House about his economic plans.

Several Republican governors have criticized Biden for supporting coronavirus mask mandates in public schools. Some of them have continued to push back on the White House following the president's announcement last week of vaccine mandates or weekly testing at private companies with 100 or more employees.