An influential federal advisory panel has roundly rejected a plan to offer Pfizer booster shots against COVID-19 to most Americans.
Friday’s 16-2 vote was a blow to the Biden administration’s effort to tighten people’s protection against the virus amid the highly contagious delta variant.
During several hours of discussion, members of the Food and Drug Administration’s external expert panel expressed frustration that Pfizer had provided little data on the safety of the additional doses.
And they complained that the data provided by Israeli researchers about their reinforcement campaign might not be adequate to predict the American experience.
The US has already approved Pfizer and Moderna boosters for certain people with weakened immune systems, such as cancer patients and transplant recipients.
Scientists inside and outside government have divided in recent days on the need for boosters and who should receive them, and the World Health Organization has strongly opposed rich nations administering a third round of injections when poor countries they do not have enough vaccine for their first.
The panel, made up of outside experts advising the Food and Drug Administration, weighed a less than clear case: while research suggests that immunity levels in those who have been vaccinated decline over time and boosters can reverse that. , the Pfizer vaccine is still around. highly protective against serious illness and death, even amid the spread of the highly contagious delta variant.
But that’s just one step in the process. The thorniest question of who should get vaccinated and when will be debated Wednesday by advisers to the Centers for Disease Control and Prevention. The CDC generally adopts the group’s recommendations, which sets policy for US vaccination drives.
The CDC has said it is considering boosters for seniors, nursing home residents and frontline healthcare workers, rather than all adults.
Separate decisions from the FDA and CDC will be needed for people who received the Moderna or J&J injections to get boosters.
At Friday’s meeting, FDA panelists heard strong arguments about the need for reinforcements from both Pfizer and Israel’s health officials, who began offering reinforcements to their citizens in July.
Sharon Alroy-Preis, from the Israel Ministry of Health, said the booster dose improves protection against infection tenfold in people aged 60 and over.
“It’s like a new vaccine,” bringing protection back to original levels and helping Israel “mitigate severe cases in the fourth wave,” he said.
And Pfizer representatives argued that it is important to boost immunity before protection against serious diseases begins to weaken. A company study of 44,000 people showed that effectiveness against symptomatic COVID-19 was 96% two months after the second dose, but dropped to 84% around six months.
Both Pfizer and Israeli representatives faced rejection from the panelists. Several expressed skepticism about the relevance of Israel’s experience to the United States. It also complicates the committee’s decision: no one yet knows the level of antibodies below which an infection is likely to occur and boosters are needed.
“That would be a great way to monitor if we really need booster shots,” said Dr. James Hildreth, president of Meharry Medical College.
FDA vaccine reviewer Dr. Philip Krause raised a series of questions about the reliability of one of the key studies that Pfizer said showed immunity is waning.
Another concern was whether the third doses would exacerbate serious side effects.
Dr. Cody Meissner of Tufts Medical Center said he is concerned about additional doses for younger age groups given the risk of heart inflammation that has been seen in most younger men after a second dose. While the condition is very rare, he said, it’s unclear whether that risk would increase with another dose.
Pfizer pointed to Israeli data from nearly 3 million boosters to suggest that the rates of side effects would be similar to those seen after second doses.
Dr. Paul Offit, a vaccine expert at Children’s Hospital of Philadelphia, said he was more likely to support the approval of a third dose for adults over 60 or 65, but “I really have trouble” endorsing it for anyone under the age of 60. 16 years.
While an additional injection will likely at least temporarily decrease cases with mild symptoms or no symptoms, “the question is what will be the impact of that in the arc of the pandemic, which may not be that much,” Offit said.