President Joe Biden on Friday urged those now eligible for COVID-19 booster shots to get the added protection a day after the Centers for Disease Control and Prevention endorsed the doses for millions of older or otherwise vulnerable Americans.

Opening a major new phase in the U.S vaccination drive against COVID-19, CDC Director Dr. Rochelle Walensky signed off on a series of recommendations from a panel of advisers late Thursday. Biden praised the decision and aimed to set aside any unease about the vaccination, saying that he would get his own booster soon.

“It’s hard to acknowledge I’m over 65, but I’ll be getting my booster shot,” Biden said. “It’s a bear, isn’t it?”

The advisers said boosters should be offered to people 65 and older, nursing home residents and those ages 50 to 64 who have risky underlying health problems. The extra dose would be given once they are at least six months past their last Pfizer shot.

However, Walensky decided to make one recommendation that the panel had rejected.

The panel on Thursday voted against saying that people can get a booster if they are ages 18 to 64 years and are health-care workers or have another job that puts them at increased risk of being exposed to the virus. But Walensky disagreed and put that recommendation back in, noting that such a move aligns with an FDA booster authorization decision earlier this week. The category she included covers people who live in institutional settings that increase their risk of exposure, such as prisons or homeless shelters, as well as health care workers.

An administration official said the White House did not have input in Walensky’s decision nor was given a heads-up. Biden on Friday said “the decision is left to the scientists and the doctors. That’s what happened here.”

The panel had offered the option of a booster for those ages 18 to 49 who have chronic health problems and want one. But the advisers refused to go further and open boosters to otherwise healthy front-line health care workers who aren’t at risk of severe illness but want to avoid even a mild infection.

The panel voted 9 to 6 to reject that proposal. Walensky decided to disregard the advisory committee’s counsel, issuing a statement saying she had restored the recommendation.

“As CDC Director, it is my job to recognize where our actions can have the greatest impact,” Walensky said late Thursday night. “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.”

It’s rare for a CDC director to overrule the panel recommendation; experts said it has only happened once this century.

Experts say getting the unvaccinated their first shots remains the top priority, and the panel wrestled with whether the booster debate was distracting from that goal. Biden stressed that the administration’s focus remained on getting people to get their first shots and that he intended to keep rolling out “vaccination requirements wherever I can.”

“The refusal to get vaccinated have cost all of us,” the president said. “It is not hyperbole: it is literally a tragedy. Don’t let it be your tragedy.”

All three of the COVID-19 vaccines used in the U.S. are still highly protective against severe illness, hospitalization and death, even with the spread of the extra-contagious delta variant. But only about 182 million Americans are fully vaccinated, or just 55 percent of the population.

“We can give boosters to people, but that’s not really the answer to this pandemic,” said Dr. Helen Keipp Talbot of Vanderbilt University. “Hospitals are full because people are not vaccinated. We are declining care to people who deserve care because we are full of unvaccinated COVID-positive patients.”

Thursday’s decision represented a dramatic scaling back of the Biden administration plan announced last month to dispense boosters to nearly everyone to shore up their protection. Late Wednesday, the Food and Drug Administration, like the CDC panel, signed off on Pfizer boosters for a much narrower slice of the population than the White House envisioned.

Copyright 2021 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.