Pfizer-BioNTech is expected to announce as soon as Tuesday that it has asked federal regulators for emergency authorization for a second booster shot of its coronavirus vaccine for adults 65 and older, according to two people familiar with the situation. The request is based heavily on data from Israel, where such shots are authorized for a somewhat broader group.
Pfizer’s chief executive, Dr. Albert Bourla, said repeatedly over the past week that he believed the additional dose would be necessary to bolster protection against infection, and that Pfizer and its partner BioNTech were submitting data in support of a request for authorization to the Food and Drug Administration.
“The protection that you are getting from the third, it is good enough, actually quite good for hospitalizations and deaths,” he told CBS’s “Face the Nation” on Sunday, referring to booster shots. “It’s not that good against infections.” The timing of Pfizer’s request was first reported by The Washington Post.
Pfizer’s move could reignite a tortuous debate among scientists that raged late last year over when and if people need booster shots. Some public health experts vigorously opposed additional shots for the general population, but then changed their minds after the Omicron variant proved more agile at evading the vaccines’ shield. Scientists continue to clash over how long the vaccines’ protection really lasts.
In an interview with Business Insider on Monday, Dr. Stephen Hoge, the president of Moderna, sounded a more cautious note than Dr. Bourla.
“For those who are immune-compromised, those who are older adults, over the age of 50 or at least 65, we want to strongly recommend and encourage” a fourth shot, he said. But he did not say how soon he thought such a shot would be needed.
Two recent studies from Israel, both published on preprint servers without peer review, arrived at mixed conclusions about a fourth shot. One study, done in conjunction with the Israeli Ministry of Health, reviewed the health records of 1.1 million people who were eligible for a fourth shot.
It concluded that those who had received the second booster of Pfizer’s vaccine were less likely to become infected with the virus or to develop severe illness. But since Israel only recently began its second booster program, researchers could not determine whether the added protection was short-lived.
A separate study of health care workers showed that while fourth shots of either Pfizer’s or Moderna’s vaccine boosted antibody levels, it had “low” efficacy at preventing infections. Researchers said those findings underscore the urgency of developing vaccines that target whatever variant is circulating.
The U.S. National Institutes of Health and various vaccine manufacturers have been studying how the vaccines could be updated.
Some senior administration officials say a fourth shot for all older Americans may make sense now, but that the general population should probably wait until the fall. The F.D.A. is expected to convene a meeting of its expert advisory committee next month to discuss the issue of fourth shots.
Asked last month whether everyone would need another injection, Dr. Peter Marks, the F.D.A.’s top vaccine regulator, said: “Barring any surprises from new variants, maybe the best thing is to think about our booster strategy in conjunction with the influenza vaccine next fall, and get as many people as possible boosted then.” Dr. Anthony S. Fauci, the chief medical adviser to the White House, has said that any recommendation would likely be aimed at those most at risk, possibly based on underlying conditions as well as age.
Senior administration officials said Tuesday that the administration is running short on funds for vaccines. While it has enough supply to offer fourth shots to older Americans this spring, if authorized by regulators, it can’t provide them to everyone without more funding from Congress, officials said.
Israel began offering a fourth shot in late December, starting with health care workers, then broadening eligibility to those 60 and older and other vulnerable groups.
The Centers for Disease Control and Prevention has recommended that many Americans with immune deficiencies get three shots as part of their initial series, followed by a fourth shot as a booster.
A study released by the C.D.C. last month showed waning protection after a booster shot of either Moderna’s or Pfizer-BioNTech’s vaccine. While the study did not break down cases by age, underlying conditions or the presence of immune deficiencies, the researchers said the findings illustrated the possible importance of a fourth shot.
The study analyzed hospitalizations and visits to emergency rooms and urgent care clinics in 10 states by people who received booster shots of either Moderna’s or Pfizer-BioNTech’s vaccine. The study showed the level of protection against hospitalization fell from 91 percent in the two months after a third shot to 78 percent after four to five months. Effectiveness against visits to emergency rooms or urgent care clinics declined from 87 percent to 66 percent.
But other recent studies suggest that three doses of a Covid vaccine — or even just two — are enough to protect most people from serious illness and death for a long period of time. While antibody levels fall off, other parts of the immune system can remember and destroy the virus over many months if not years, according to at least four studies published in top-tier journals in recent weeks.