They recommended a more limited step: emergency use authorization for people 65 years of age and older and for people at high risk of serious infection. Then they came back and added health workers and others at high risk of getting infected at work – even if they weren’t at particularly high risk for serious illness.
But why not just go ahead and say anyone who wants a booster can get one? Members of the Advisory Committee on Vaccines and Related Biologics spoke effusively as to why.
Even Pfizer said its vaccine is still very successful in preventing serious illness, hospitalizations and death in the United States, with an effectiveness of over 90%. The company argued that it might not last longer, but many VRBPAC members did not buy it.
They don’t see enough evidence to warrant booster shots for everyone
“In my opinion, we need this in our arsenal – a booster now, especially for the elderly and (those with) other high-risk conditions – but I share my colleagues’ angst about the issue. the paucity of safety data, ”said Dr. Mark Sawyer, professor of clinical pediatrics at the University of California, San Diego.
“I hope the CDC will roll this out gradually.”
Dr Michael Kurilla, an infectious disease specialist at the National Center for Advancing Translational Sciences, said he suspected Pfizer was going too far in extrapolating data on the elderly to a younger population.
“So it’s not clear that everyone needs strengthening except for a subset of the population who would clearly be at high risk for serious illness,” Kurilla said. “It’s not clear to me that the data we’re seeing right now is applicable to the general population.”
They would like a lot more data and a chance to look for the wrong conclusions
Dr Philip Krause, deputy director of the FDA’s Office of Vaccine Research and Review, noted that Pfizer was using data that had not been reviewed by experts.
“One of the problems is that much of the data that has been presented and discussed today is not peer reviewed and has not been reviewed by the FDA,” Krause said.
Krause, along with another FDA vaccine official, Marion Gruber, signed an article published by The Lancet earlier this week, saying it was too early to start giving people reminders.
Kurilla noted that Pfizer’s studies relied heavily on antibody measurements, without examining other important aspects of the immune response.
“It’s a little disappointing that there have been very few reports on cellular immune responses and that the focus is entirely on neutralizing antisera,” Kurilla said. Immunologists point out that lasting protection comes from immune cells called B cells and T cells, and Pfizer only presented data on the antibody response.
“We lack data, including solid data on the vaccine doses that were administered,” said Dr. Hayley Ganz, professor of pediatrics at Stanford University Medical Center.
They worry about young adults and teens
“We are being asked to approve this as a three dose vaccine for people 16 years of age and older, without any clear evidence, the third dose for a younger person, compared to an older person, has value.” , Offit said. .
“If it is not of value, then the risks may outweigh the benefits. And we know that the 16 to 29 year old is at higher risk for myocarditis,” he added.
Dr Doran Fink of the FDA told the meeting that the agency was not sure either. “We really don’t have enough data yet to know what the risk of myocarditis or pericarditis would be following a booster dose,” he said. Studies have shown that young adults and older adolescents, especially men, are at a higher risk for this rare heart inflammation after receiving an mRNA vaccine like that from Pfizer, although the problem resolves quickly with a fast processing.
Details on that risk might not come out, however, Fink said, until the booster doses have been administered more widely.
“We have discussed the need for such surveys with vaccine manufacturers,” Fink said.
“I don’t think we would feel comfortable giving it to a 16 year old for all the reasons everyone has mentioned,” said Dr Eric Rubin, chair of the Department of Immunology and Diseases. infectious diseases from the Harvard TH Chan School of Public Health.
They think it’s more important to get more people vaccinated the first time
Dr Cody Meissner, professor of pediatrics at Tufts University School of Medicine, said he didn’t think boosters would significantly help control the pandemic.
“It is very important that the main message that we are still sending is that we have to get two doses for everyone. Everyone has received the primary series,” he said. “This booster dose is not likely to make much of a difference in the behavior of this pandemic.”
“It’s a frustrating place when we have more than enough vaccine stocks in the United States and yet we have not been able to achieve the level of coverage that would better control the pandemic than we have,” said Dr Melinda Wharton, director of the division of immunization services at the U.S. Centers for Disease Control and Prevention.
“Boosters are probably not the action that will have the greatest impact on health in the United States,” she said.