President Joe Biden said 60 million Americans who have received the Pfizer-BioNTech Covid-19 vaccine will soon have access to a booster shot after top health officials overruled an advisory panel on the issue.
“We took a key step in protecting the vaccinated with booster shots, which our top government doctors believe provides the highest level of protection available to date,” Mr Biden said on Friday at the White House.
Centres for Disease Control and Prevention (CDC) Director Rochelle Walensky issued a statement late on Thursday saying that a third shot could be given to certain adults who have received the Pfizer vaccine six months after their second dose.
Her statement broadened eligibility for the shots beyond the recommendations of a CDC advisory panel, but Mr Biden said Dr Walensky was in line with medical science.
“The decision of which booster shot to give, when to start the shot and who will get them is left to the scientists and the doctors,” Mr Biden said. “That’s what happened here.”
On Thursday, the CDC’s Advisory Committee on Immunisation Practices panel unanimously voted to recommend Pfizer's Covid-19 vaccine booster shot for those over the age of 65, to be administered at least six months after initial vaccination.
The independent group also voted to endorse giving the booster to Americans between the ages of 50 and 64 who have underlying medical conditions and for people with “individual benefit and risk” between 18 and 49 years old with underlying medical conditions.
The panel voted not to recommend boosters for healthcare workers.
Dr Walensky approved all recommendations but overruled the last vote on healthcare workers to allow people aged 18 to 64, who have no underlying medical conditions but who work in places with a high chance of Covid-19 exposure, to receive a third dose.
The agency chief does not have to follow the panel's recommendations but often does, making Dr Walensky's move unusual. However, her decision was in line with recommendations from the Food and Drug Administration.
On Wednesday, the FDA issued emergency authorisation for a booster dose for people over the age of 65 and for people whose job puts them at risk of infection.
All of Dr Walensky's recommendations pertain only to people who initially received the Pfizer shot.
About 100 million people in the US have been fully vaccinated with the Pfizer shot. Mr Biden said that 60 million will eventually be eligible for boosters, though only 20 million are immediately eligible because six months have elapsed since their second shot.
The widespread dispensing of the boosters would represent an important new phase in the US vaccination drive.
Mr Biden last month announced his administration's plans to begin the booster roll-out this week.
In comments delivered to the CDC's Advisory Committee before Thursday's vote, some members expressed worry that the focus on boosters would distract from the larger problem: vaccinating the unvaccinated.
“We're fighting a pandemic and it's not because people got two doses of the vaccine. It's because people are unvaccinated,” said Dr Helen Keipp Talbot, professor of medicine at Vanderbilt University.
Millions of Americans are still likely to be confused over the CDC's decision, as the US government has not considered boosters for the Moderna or Johnson & Johnson vaccines.
Advisory committee member Dr Pablo Sanchez said he “doesn't think we can continue to ignore that population”, referencing Americans who received the single-dose Johnson & Johnson shot.
US-manufactured Covid-19 vaccines still offer strong protection against severe disease, hospital admission and death, but immunity against milder symptoms appears to wane several months after the initial vaccination.
Last week, the FDA advisers overwhelmingly rejected Pfizer's booster proposal for the general population, saying there was not enough evidence to support boosters for those aged 16 and older.
The US has already authorised third doses of the Pfizer and Moderna vaccines for certain people with weakened immune systems.
Mr Biden asked Americans who received the Pfizer shot as well as those with Moderna and Johnson & Johnson vaccinations but are not yet eligible for a booster to wait their turn.
“In the near term, we’re probably going to open this up anyway,” he said. Everyone “basically across the board” will eventually be able to receive another shot, he said.