The Food and Drug Administration authorized Pfizer and BioNTech‘s Covid-19 booster shots for people 65 and older and other vulnerable Americans, in line with recommendations given Friday by its key vaccine advisory committee.

The FDA’s decision comes after a more than 8-hour agency meeting Friday where a panel of outside experts debated and voted on Pfizer’s application to offer booster shots to the general public. After voting 16-2 in favor of distributing vaccines to Americans aged 16 and over, the FDA’s Vaccines and Related Biological Products Advisory Committee voted unanimously for an alternative plan that would give boosters to seniors and people at high risk of severe illness if they contract the virus.

FDA issued an emergency authorization for the administration of the vaccines to seniors, people with co-morbidities or front-line healthcare workers who are at greater risk from the disease.

In a statement, Dr. Peter Marks (the FDA’s top vaccine regulator) said that “the FDA took into account the input of the committee and performed its own thorough analysis of the submitted data in order to reach today’s decision.” We will continue to review the FDA data regarding the booster use of COVID-19 vaccinations. Based on this data, we will take further actions as necessary. 

The nonbinding decision by the vaccine advisory committee was expected to be a controversial one as the Biden administration has said it wants to begin offering booster shots to the general public as early as this week, pending authorization from U.S. health regulators.

The agency sometimes follows the advice of its advisory committee. After the vote, Marks reminded them that the federal regulators didn’t have to agree with the recommendation.

Marks asked for input from the group on which other population the FDA should consider for boosts. He suggested that the FDA look into front-line healthcare workers, and any other professions more susceptible to Covid. Your vote does not make us obligated to FDA. “We can adjust this as necessary,” he stated.

Some experts in health speculate that the agency may not adhere to the guidelines of its committee. Some scientists, including at least two at the FDA, had said they weren’t entirely convinced every American who has received the Pfizer vaccine needed extra doses at this time. But, in August, Biden’s booster program was supported by the country’s top health regulators. These included Dr. Rochelle Walensky (CDC Director), Dr. Janet Woodcock (acting FDA Commissioner) and Dr. Anthony Fauci (White House chief medical advisor).

This vote places the committee in an awkward position as the administration already stated they will begin distribution of boosters this month. Northwell Health chief for infectious disease Dr. Bruce Farber spoke before the recommendation.

Some members of the committee expressed concern that not enough data was available to make a recommendation before the vote, which took place in the afternoon. Others suggested third shots be restricted to people older than 60, who have been known to be more at risk for severe diseases. Some of the members raised concern about myocarditis risk in young people and suggested that further research be done.

Phil Krause is an FDA vaccine regulator and has resigned from the agency due to pressure by the Biden Administration to approve shots. He was critical about the presentation of findings at the meeting. Krause stated that many of the data hadn’t been peer-reviewed or reviewed by federal agencies. According to Krause, the complex models used meant scientists had to verify that the results were correct.

He stated that this is part of what makes it difficult to look at data like this without FDA approval.

In outlining plans last month to start distributing boosters as early as this week, administration officials cited three CDC studies that showed the vaccines’ protection against Covid diminished over several months. At the time, senior officials in health said they were worried that protection against serious disease, hospitalization, and death could decrease over the next few months, particularly among people who have been exposed to greater risks or had not received vaccinations during the initial phases of the rollout.

Pfizer published documents that showed that the protection against infection was restored to 95% in an observational Israeli study. Data were collected between July 1, and August 30, during the rapid-growing delta variant.

Sharon Elroy-Preiss from Israel’s Health Ministry presented Friday. She said that, if boosters hadn’t been distributed by July 31, the nation would not have had enough hospital beds. According to her, health officials started to notice a pattern in which people aged 40- and 50 who were completely vaccinated became seriously ill with Covid.

The committee was informed by her that they didn’t want the results to be delayed and decided to vaccine a greater percentage of people to reduce the number of cases. She said that severe cases were expected to be at an average of 2,000 in Israel by August’s end. We were able dampen this effect, and now our severe cases average 700 cases or less. This has remained stable despite still having 10,000 cases confirmed.

However, the FDA OK does not mean that it is final. Tuesday was the start of the second day for the Centers for Disease Control and Prevention’s vaccine advisory committee. This meeting included a discussion on third shots and a vote about the FDA’s proposal. If they make a recommendation that is accepted by the CDC then booster shots may be given immediately.