WASHINGTON – The only Americans not yet eligible for coronavirus vaccines — infants, toddlers and preschoolers — appear on the verge of finally getting the go-ahead to receive them after a Food and Drug Administration advisory panel Medicines (FDA, for its acronym in English) voted unanimously on Wednesday to recommend the Pfizer and Moderna vaccines. for the group
The FDA appears poised to license Moderna’s vaccine for children under 6 and Pfizer’s for children under 5 as soon as Friday. States have already ordered millions of doses, and White House officials said injections could start as early as next week.
The committee’s 21-0 votes came after a day-long review of clinical trial data and marked the end of a process that involved months of false starts and dashed hopes that a vaccine would cover the youngest Americans. youths. Except for the roughly 20 million children under the age of 5, all have had access to coronavirus vaccines for many months and are now eligible for booster shots.
The FDA and the Centers for Disease Control and Prevention jointly pushed through a positive recommendation, showering the committee with 230 pages of data they said showed the vaccines were safe and elicited a strong immune response in children. Regulators also stressed that while young children are generally at low risk of severe illness from the virus, vaccinating the group would save lives.
“We have to be careful not to become insensitive to the number of pediatric deaths because of the overwhelming number of deaths of older people here,” said Dr. Peter Marks, the FDA’s chief vaccine regulator. “The intervention that we’re talking about here is something that we’ve accepted in the past to try to prevent deaths from influenza,” he added.
CDC officials said more than half of the young children hospitalized with Covid had no underlying medical conditions. During the Omicron wave in the winter, younger children were hospitalized at higher rates than older children and adolescents, and their illness tended to be at least as severe. More than 200 children ages 6 months to 4 years have died of covid, according to death certificate data, one of the most conservative estimates.
The panel members, some of whom have treated children hospitalized for Covid and comforted terrified parents, seemed eager to act.
“There are so many parents who are absolutely desperate to get this vaccine,” said Dr. Jay Portnoy, a professor of pediatrics at the University of Missouri-Kansas City School of Medicine. “I think we owe it to them to give them the choice.”
Dr. Arthur Reingold, an epidemiologist at the University of California, Berkeley, School of Public Health, said the nation already vaccinated children against diseases “where the risk of a child dying or being hospitalized from those diseases was pretty close.” steel”.
The CDC’s own panel of vaccine experts will take up the matter for two days this weekend. If that committee also makes a favorable recommendation, Dr. Rochelle P. Walensky, the agency’s director, would issue her decision, the final step in the process.
No vaccine has been tested against new subvariants circulating in the United States. Clinical trials were largely conducted when the Omicron variant was prevalent. Two subvariants, BA.4 and BA.5, could become dominant within a month.
The virus is evolving so fast that some panelists expressed fear that the clinical trial results on which their decisions were based were already out of date. “We’re really trying to predict the future,” Dr. Paul Offit, a vaccine expert at Children’s Hospital of Philadelphia and an FDA panelist, said in an interview. “This is a problem.”
But the panel’s biggest concern seemed to be whether Pfizer’s three-dose vaccine, which it developed with its German partner, BioNTech, was effective enough. Pfizer has reported that two doses of its vaccine were only 28 percent effective in preventing symptomatic disease; FDA reviewer Dr. Susan Wollersheim said the company’s data did not clearly show that two doses reduced the incidence of Covid.
Pfizer argued that three doses were 80 percent effective, but the finding was based on just 10 cases from a subset of 1,678 trial participants. And Dr. Doran Fink, acting deputy director of the FDA’s office of vaccines, questioned the company’s estimate, calling it “preliminary” and “inaccurate.”
Still, he said the FDA was “very confident” from immune response data that Pfizer’s vaccine, like Moderna’s, met the criteria for emergency use authorization, which requires benefits to outweigh risks. . But some panel members were clearly worried that parents might be misled.
Dr. Amanda Cohn, a senior CDC official and member of the panel, said she had “no idea” what the efficacy rate after three doses of Pfizer will end up being, and that officials should not adopt the 80 percent.
Jeannette Y. Lee, a biostatistician at the University of Arkansas for Medical Sciences, raised another concern: that some parents might miss the crucial third dose for their children. “As we know, it’s a struggle to get people involved for two,” she said.
Pfizer officials said the data showed the vaccine’s effectiveness increased over time. “It’s not that there’s no efficacy at all,” said Dr. William C. Gruber, a senior vice president at Pfizer.
For some parents, the bar is low. Some of the more than 1,600 parents who responded to a New York Times query about living with an unvaccinated toddler said they would accept any efficacy above zero to give their children some protection.
“To keep her safe from illness and possible death or lifelong hardship? Why is it a question? wrote Cayla Miller, a mother in Swanville, Maine. “We have been waiting so long to protect our entire family. I almost lost my job and my mind trying to keep her safe.”
Scientists and federal officials have warned against directly comparing Moderna and Pfizer vaccines. Not only did the companies conduct their clinical trials at different times, with different populations, but they also differed in dosages and regimens.
Pfizer has proposed a three-dose regimen at one-tenth the adult dose, with the first two doses spaced three weeks apart and the third at least two months after the second. Moderna wants to offer two doses of the vaccine, four weeks apart, at a quarter of the strength of its adult dose. Moderna’s adult dose is significantly stronger than Pfizer’s.
The FDA’s Dr. Wollersheim declined to respond when a panelist requested a comparison of the effectiveness of vaccines in young children. But as some parents can do, some panelists tried to make their own comparison.
Dr. Offit noted that Moderna’s efficacy data was slightly stronger than Pfizer’s: about 51% effective in preventing symptomatic infections in children 6 months to 2 years old and 37% effective in children from 2 to 5 years.
Although protection against symptomatic infection was limited, he said, it was possible to predict that Moderna’s vaccine would prevent serious illness.
“I’m not so sure you can predict that with the Pfizer vaccine,” he said. “I’m afraid they may have underdosed.”
Both vaccines elicited levels of neutralizing or virus-blocking antibodies among children comparable to those of young adults. Pfizer’s vaccine has been licensed for children ages 5 to 15 since last year, and regulators said it helped prevent hospitalizations and deaths.
Still, both appear significantly less effective against symptomatic infection than the adult vaccines when they were introduced 18 months ago. The FDA said that was because Omicron proved much more adept at evading vaccine defenses against infection than earlier versions of the virus.
Given the evidence of decreased potency over time, the F.A. has said that young children receiving injections from Pfizer and Moderna will likely require booster injections, just like older children. That would mean Pfizer’s vaccine could end up in four doses, while Moderna’s could end up in three.
Neither vaccine caused serious safety problems. The vast majority of side effects were mild: irritability and crying, drowsiness, fatigue, and loss of appetite. Recipients of Moderna’s vaccine appeared more likely to experience fever, but in line with those caused by other pediatric vaccines, the FDA said.
Federal health officials have said they expect many children under the age of 5 to be vaccinated by pediatricians and primary care physicians, in contrast to older age groups. But uptake is expected to be low; children ages 5 to 11 became eligible to be vaccinated late last year, but only about 37 percent of them received at least one dose.
Doses are packaged by the hundreds to reach smaller practices and rural locations. The Biden administration has also announced a network of other places that would work to reach families, including pharmacies and children’s hospitals, while groups like the Association of Children’s Museums and the National Network of Diaper Banks will help with educational efforts.
One topic of discussion among members of the FDA panel was how to address the many parents whose children have already acquired some natural immunity. Federal health officials presented data to the committee this week suggesting that more than two-thirds of children ages 1 to 4 have already been infected with the virus.
A Moderna official told the committee that the company’s trial found that young children who had contracted the virus and were vaccinated had higher levels of protection, a conclusion supported by external investigation.
Committee member Dr. James EK Hildreth, president of Meharry Medical College in Nashville, noted that many children had been infected “and have done well.”
“But for those parents who choose to do it, especially those parents of children with underlying conditions,” he added, “this is an option that they should have.”
emily erdos contributed report.