This story was updated Sept. 24, 2021.

Sept. 23, 2021 – The director of the CDC late Thursday overruled the recommendation of the agency’s advisory panel to broaden the number of Americans who are now eligible for a third dose of the Pfizer COVID-19 vaccine.

The CDC’s Advisory Committee on Immunization Practices earlier Thursday voted to allow several groups of Americans to get a booster shot, but voted not to recommend it for adults age 18 to 64 who live or work in a place where the risk of COVID-19 is high. The vote meant health care workers and other frontline employees would be excluded from the list of those eligible for a booster.

But CDC Director Rochelle Walensky, MD, decided to reverse that recommendation and include the 18-to-64-year-olds -- and health care workers and frontline employees - in her final decision.

"As CDC Director, it is my job to recognize where our actions can have the greatest impact," Walensky said in a statement after midnight Thursday. "At CDC, we are tasked with analyzing complex, often imperfect data to make concrete recommendations that optimize health. In a pandemic, even with uncertainty, we must take actions that we anticipate will do the greatest good."

Walensky agreed with the rest of the advisory committees decisions, which included recommendations that the following groups also be eligible for a booster shot if they already received the Pfizer vaccine before:

  • Adults ages 65 and up and residents of long-term care facilities
  • Adults ages 50 to 64 who have an underlying medical condition that may increase their risk from a COVID infection
  • Adults ages 18 to 49 who may be at increased risk from a COVID-19 infection because of an underlying medical condition, if a person feels like they need one based on a consideration of their individual benefit and risks.

About 26 million Americans are at least 6 months past the last dose of the Pfizer vaccines, making them eligible to receive a third dose.  About 13.6 million of them are over the age of 65.  Another 5.3 million are ages 50 to 64.

No Boosters for Healthcare, Frontline Workers

In making the recommendations, the committee left out healthcare workers. This was a departure from the FDA's authorization which included boosters for those 65 and over, and for people 18 through 64 years of age who are at high risk for severe illness from the coronavirus, including essential workers – such as those in healthcare -- whose jobs increase their risk for infection.

This is the group Walensky added to the eligible list on her own.

Committee members “did not buy the need in occupational or institutional settings,” said William Schaffner, MD, an infectious disease specialist at Vanderbilt University in Nashville, TN. .  Schaffner sits on the ACIP work group that considered the evidence behind boosters. He said   that he would have voted yes to offer boosters to healthcare and other essential workers.

“There was a real split in the committee,” he said.

The vote on boosters for healthcare and other high-risk workers was rejected 9 to 6.

“I think that there is ample evidence that people such as a healthcare workers do not have repeated exposure in the workplace,” said Beth Bell, MD, a clinical professor at the University of Washington. “They're using PPE as they should and they're following the other policies within the healthcare setting. There's lots of evidence that suggest that health care workers who become infected become infected because of exposures in the community.”

She was not alone in feeling cautious.

“I think this is an extremely slippery slope,” said Sarah Long, MD, a pediatric infectious disease specialist at Drexel University in Philadelphia, before her vote to reject boosters for healthcare and other high-risk workers.

“We might as well just say, ‘Give it to everybody 18 and over.’ We have an extremely effective vaccine. It’s like saying it’s not working and it is working.”

The committee saw data showing that all of the vaccines remain highly protective against hospitalization and death for all age groups, though protection against getting sick with COVID has waned slightly over time and with the dominance of the more contagious Delta variant. Those at highest risk for a severe breakthrough infection — those that cause hospitalization or death — are older adults.

How Much Will the U.S. Benefit from Boosters?

Some felt squeamish about broadly recommending boosters at all.

“We have too much hope on the line with these boosters,” said James Loehr, MD, who is a family practice doctor in Ithaca, NY. Loehr said he felt like the goal of giving boosters in the U.S. should be to decrease hospitalizations, and he felt they would, but that the impact would likely be smaller than appreciated.

Based on his calculations of the benefits of boosters for each age group, Loehr said if boosters were given to all 13 million seniors previously vaccinated with the Pfizer vaccine, we might prevent 200 hospitalizations a day, “which would be a lot,” he noted. But, he said, “considering that we have 10,000 hospitalization a day now, it’s probably not that much.”

Others agreed.

“I really think this is a solution looking for a problem,” said Jason Goldman, MD, an associate professor at Florida Atlantic University who was representing the American College of Physicians. “You know, I don't think it's going to address the issue of the pandemic. I really think it's just going to create more confusion on the provider from the position of implementation, and I really think it's going really far afield of the data.”

ACIP Chair Grace Lee, MD, a pediatric infectious disease specialist at Stanford, said she had cared for children who had died of COVID.

“I can tell you that their family members really wished they had extra protection for their kids, because they weren’t symptomatic. Nobody else was sick at home,” she said.

Lee said for her, access was paramount, and she was in favor of expanding access to boosters for as many people as possible.

Next Steps

The recommendations would have -- before Walensky stepped in -- effectively narrowed the scope of the FDA’s Emergency Use Authorization for the Pfizer vaccine, which had included people who live or work in high-risk settings.

“This was a group that wanted to use a rifle rather than a shotgun,” said Schaffner.

One of the panel members tried to propose revised wording for a fifth vote, but the meeting was concluded because of the late hour.

Lee, the ACIP chair, closed the meeting by reminding the public that the recommendations were temporary and that the committee would be back to reconsider the issue of third doses again soon.

For now, people who were initially vaccinated with either Moderna or Johnson & Johnson vaccines are excluded from booster recommendations, something many on the committee were uncomfortable with.

The FDA is still considering Moderna’s application to market booster doses. Johnson & Johnson hasn’t yet applied to the FDA for permission to offer second doses in the U.S.

While the ACIP’s recommendations are important, in this case, they may not have a huge practical effect, said Schaffner. The CDC has already approved third shots for people who are immunocompromised, and no proof of a medical condition is required to get one.

More than 2 million people have already gotten a third dose, he noted, and not all of them are immunocompromised.

“They have heard the president say that, you know, everybody should get a booster, and they've taken that at face value,” he said.