News Desk :
A key advisory panel to the Food and Drug Administration overwhelmingly rejected recommending Pfizer booster shots for most recipients of the company’s coronavirus vaccine, instead endorsing them only for people who are 65 or older or at high risk of severe Covid-19, and received their second dose at least six months ago.
The vote – the first on boosters in the United States – was a blow to the Biden administration’s strategy to make extra shots available to most fully vaccinated adults in the United States eight months after they received a second dose. The broader rollout was to start next week.
Committee members appeared dismissive of the argument that the general population needed booster shots, saying the data from Pfizer and elsewhere still seemed to show two shots protected against severe disease or hospitalization and did not prove a third shot would stem the spread of infection. Some also criticized a lack of data that an additional injection would be safe for younger people.
“It’s unclear that everyone needs to be boosted, other than a subset of the population that clearly would be at high risk for serious disease,” said Dr. Michael G. Kurilla, a committee member and official at the National Institutes of Health.
But the panel’s final recommendation left some room for the White House to argue that the core of its booster strategy remained intact. Depending on how “at high risk” is defined, tens of millions of Americans could conceivably wind up eligible for additional shots of the Pfizer vaccine.
The committee of largely outside experts voted 16 to 2 against a Pfizer booster for
people 16 and older after a tense daylong public discussion that put divisions in the agency and the administration on public display. Officials from the Centers for Disease Control and Prevention and the National Institutes of Health joined infectious disease experts and doctors in voting against additional shots for such a broad swath of the population.
Dr. Paul A. Offit, a committee member and the director of the Vaccine Education Center at Children’s Hospital of Philadelphia, questioned whether extra shots would do much at all to change the arc of the pandemic. “We all agree that if we really want to impact this pandemic, we need to vaccinate the unvaccinated,” he said.
But the panel unanimously embraced a fallback position to limit additional shots to older adults and others at high risk of severe Covid illness. Then, after an informal poll pushed by a senior F.D.A. official, committee members specified that health care workers, emergency responders and others whose jobs put them at special risk should also be eligible for the booster shots. The official – Dr. Peter Marks, who oversees the F.D.A.’s vaccine division – said the at-risk group would also include teachers.
The F.D.A. has the final word on vaccine approvals, and while it is not obliged to follow the committee’s recommendations, it typically does. The agency is likely to issue a decision by early next week.
An advisory committee of the C.D.C. is scheduled to meet Wednesday and Thursday to discuss booster shots before that agency, which sets vaccine policy, issues recommendations on who exactly should receive them.
Meanwhile, two weeks after Biden’s announcement, leaders of the F.D.A. and the C.D.C. told the White House that it would be impossible to authorize booster shots for recipients of the Moderna vaccine that soon.
Then, in a remarkable public display of internal dissension, two F.D.A. scientists wrote a medical journal article this week arguing that there was no credible evidence yet in support of boosters for the general population. Those officials, who are leaving the agency this fall, joined outside experts at the Friday meeting in casting doubt on whether Pfizer’s request should be approved.
Dr. Sara Oliver of the C.D.C. presented data showing that vaccines continue to strongly protect against severe forms of Covid-19 in the United States, even in people 75 and older.
Jonathan Sterne, a professor of medical statistics and epidemiology in Britain, said he had analyzed 76 different studies on the vaccines’ real-world effectiveness and found that multiple factors could skew the results, including how many unvaccinated people in a study had natural immunity from prior infection. He also warned against drawing conclusions from short-term results from booster shots; data from Israel, for example, only included a follow-up period of several weeks for older adults.
Israeli experts made a different argument, telling the committee that they believed third Pfizer shots helped dampen a fourth wave of transmission as the Delta variant swept the nation this summer. The Israeli government, which has relied almost entirely on the Pfizer vaccine, began offering booster shots in late July, starting with the older adults.
Dr. William C. Gruber, a senior Pfizer vice president in charge of vaccine development, suggested that if the United States does not follow Israel’s lead, it could face more than five million more infections a year among people who received their second dose 10 months earlier, compared to those who got the second shot five months earlier.
“Israel could portend the U.S. Covid-19 future, and soon,” he said.
He said Pfizer’s data showed that a third shot elicited a robust antibody immune response that equaled or greatly exceeded the response after the second dose. Data also show, he argued, that breakthrough infections among vaccinated Americans are linked more to the ebbing power of the vaccine over time than to the Delta variant.
But committee members and some government officials appeared deeply skeptical. Dr. Philip Krause, one of the F.D.A. vaccine experts who wrote the medical journal review, criticized Pfizer’s presentation of data that had not been peer-reviewed or evaluated by the F.D.A., arguing that problems in the modeling in a study underpinning the company’s case understated the vaccine’s efficacy.
One study apparently came too late for the discussion, underscoring the rapid flurry of changing data on vaccine potency. Released by the C.D.C. hours before the committee’s vote, it found that the Pfizer vaccine’s level of protection against coronavirus hospitalizations dropped significantly four months after the second shot.
The study found that two weeks to four months after recipients got their second dose, the Pfizer vaccine was 91 percent effective in preventing hospitalization. After 120 days, though, its effectiveness fell to 77 percent. Moderna’s vaccine showed no comparable decrease in protection over the same time frame. The vaccinated patients in the study tended to be older; the Pfizer cohort had a median age of 68.
Courtesy: The New York Times
