WASHINGTON — The only Americans still ineligible for coronavirus vaccines — babies, toddlers and preschoolers — look set to finally be allowed to receive them after an advisory group of the Food and Drug Administration voted unanimously on Wednesday to recommend the Pfizer and Moderna vaccines for the group.
The FDA appears poised to clear Moderna’s vaccine for children under 6 and Pfizer’s for those under 5 as of Friday. States have already ordered millions of doses, and White House officials have said injections could be launched 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 of a vaccine to cover the most young Americans. Everyone except the roughly 20 million children under the age of 5 has had access to coronavirus injections for many months and is now eligible for booster shots.
The FDA and the Centers for Disease Control and Prevention jointly pushed for a positive recommendation, flooding 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 serious illness from the virus, vaccinating the group would save lives.
“We have to be careful not to become numb to the number of pediatric deaths because of the overwhelming number of older deaths here,” said Dr. Peter Marks, the FDA’s lead vaccine regulator. “The intervention we’re talking about here is something we’ve agreed to in the past to try to prevent flu deaths,” he added.
CDC officials said more than half of young children hospitalized with Covid had no underlying medical conditions. During the Omicron surge in winter, young children were hospitalized at a higher rate than older children and adolescents, and their illnesses tended to be at least as severe. More than 200 children aged between 6 months and 4 years have died from Covid, according to death certificate data which is one of the most conservative estimates.
Panel members, some of whom have treated children hospitalized with 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, 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 country was already vaccinating children against diseases “where the risk of a child dying or being hospitalized for those diseases was quite close. of zero”.
The CDC’s own panel of vaccine experts is expected to address the issue for two days this weekend. If that committee also gives a favorable recommendation, Dr. Rochelle P. Walensky, director of the agency, would render her decision, the final step in the process.
Neither 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 changing so rapidly that some panelists expressed concern that the results of the clinical trials on which their decisions were based are already outdated. “We’re really trying to predict the future,” said Dr. Paul Offit, vaccine expert at Children’s Hospital of Philadelphia and FDA panelist, in an interview. “It 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 reported that two doses of its vaccine were only about 28% effective in preventing symptomatic disease; Dr Susan Wollersheim, an FDA reviewer, said the company’s data did not clearly show that two doses reduced the incidence of Covid.
Pfizer argued that three doses were 80% effective, but the conclusion was based on just 10 cases out of 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 is “very confident” from immune response data that Pfizer’s vaccine, like Moderna’s, meets the criteria for emergency use authorization, which requires benefits outweigh the risks. But some panelists were clearly concerned that parents were being misled.
Senior CDC official and panel member Dr. Amanda Cohn said she had “no idea” what the effectiveness rate will be after three doses of Pfizer, and that officials should not accept the 80% estimate.
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 hard to get people in for two,” she said.
Pfizer officials said the data showed the vaccine’s effectiveness built over time. “It’s not like there’s no efficacy,” said Dr. William C. Gruber, senior vice president at Pfizer.
For some parents, the bar is set low. Some of the more than 1,600 parents who responded to a New York Times question about living with an unvaccinated young child said they would accept anything greater than zero to give their children some protection.
“To protect her from illness and potential death or lifelong hardship? Why is this a question? wrote Cayla Miller, a mother from Swanville, Maine. “We have waited so long to protect our whole family. I almost lost my job and my mind trying to protect her.
Scientists and federal officials have cautioned against directly comparing Moderna and Pfizer vaccines. Not only have the companies conducted their clinical trials at different times, with different populations, but the dosage and treatment regimens differ.
Pfizer offered a three-dose regimen at one-tenth the strength of its 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 answer when a panelist asked for a comparison of vaccine effectiveness in young children. But as some parents can do, some panel members tried to make their own match.
Dr. Offit noted that Moderna’s efficacy data was somewhat stronger than Pfizer’s: about 51% efficacy in preventing symptomatic infections in children 6 months to 2 years of age and 37% efficacy in children from 2 to 5 years old.
Even if protection against symptomatic infection was limited, he said, it was possible to predict that Moderna’s vaccine would ward off severe disease.
“I’m not sure you can predict that with Pfizer’s vaccine,” he said. “I’m afraid they underdosed.”
Both vaccines elicited levels of neutralizing or blocking antibodies in children comparable to those in 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.
Yet both appear significantly less effective against symptomatic infection than adult vaccines when they were introduced 18 months ago. The FDA said this was because Omicron was found to be much more adept at evading vaccine defenses against infection than previous versions of the virus.
Given the evidence of diminishing potency over time, the FD.A. said young children who receive injections from Pfizer and Moderna will likely need boosters, as will older recipients. This would mean that Pfizer’s vaccine could end in four doses, while Moderna’s could be three.
Neither vaccine has raised serious safety concerns. The vast majority of side effects were mild – irritability and crying, drowsiness, fatigue, and loss of appetite. Recipients of Moderna’s vaccine seemed more likely to experience fevers, but consistent with those caused by other childhood vaccines, the FDA said.
Federal health officials said they expect many children under the age of 5 to be vaccinated by pediatricians and primary care physicians, unlike older age groups. But adoption is expected to be low; children aged 5 to 11 became eligible for vaccination late last year, but only around 37% received at least one dose.
Doses are packaged in the hundreds to reach small practices and rural areas. The Biden administration also announced a network of other places that would work to reach families, including pharmacies and children’s hospitals, while groups such as the Association of Children’s Museums and the National Diaper Bank Network will contribute. to educational efforts.
One of the topics of discussion among the FDA panel members 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 between the ages of 1 and 4 have already been infected with the virus.
A Moderna official told the committee that the company’s trial found that young children who contracted the virus and were vaccinated had higher levels of protection, a finding supported by outside research.
Dr. James EK Hildreth, committee member and president of Meharry Medical College in Nashville, noted that many children had been infected “and had done very well.”
“But for parents who choose to do so, especially parents of children with underlying conditions,” he added, “it’s a choice they should have.”
Emilie Erdos contributed report.