In reversal, the FDA delays push for shots for children younger than 5
By Sharon LaFraniere and Noah Weiland
In a striking reversal, federal regulators late last week said they would wait for data on how well three doses of Pfizer-BioNTech’s coronavirus vaccine work in children younger than 5 before deciding whether to authorize the vaccine for that age group.
The decision by the Food and Drug Administration most likely rules out shots for roughly 18 million of the nation’s youngest children until at least April. The Biden administration had been hoping to expand vaccination to those 6 months through 4 years of age as early as next week. They are the only Americans not yet eligible for shots.
Pfizer-BioNTech asked for the delay after the companies discovered that the omicron wave had led to a far higher rate of infection than they had previously recorded among young volunteers in their clinical trial. The new data underscored that the omicron variant was better than the earlier delta variant at evading the vaccine’s protection, and it showed that two doses, which had already fallen short by another measure, were not effective enough.
As a result, the companies and the FDA agreed to wait for the results from a third dose, which are expected in early April.
The turnabout came as the Centers for Disease Control and Prevention on Friday released data showing that booster shots of the Pfizer and Moderna vaccines lose some of their effectiveness against emergency room visits and hospitalizations by the four-month point. The agency said the data was some of earliest evidence on the durability of boosters. Although it showed three doses offered better protection than two, it raised sobering questions about how long that protection lasts against severe disease.
Together, the two developments dampened some earlier optimism about vaccines. They also presented at least a temporary setback for the Biden administration’s vaccination campaign.
Researchers hope that by April, Pfizer and BioNTech will be able to demonstrate that three doses protect children, with data showing both stronger immune responses and more success in warding off symptomatic infections.
The companies said in a news release that they would wait for the data on a three-dose vaccine given the study’s rapid pace and because they “continue to believe it may provide a higher level of protection in this age group.”
The FDA began pressing Pfizer-BioNTech to seek authorization for a two-shot regimen weeks ago, despite disappointing results from the trial that were announced in December. Children ages 2-4 produced only 60% of the antibody levels that older teens and young adults did. The older age group was used as a bench mark because the vaccine had proved effective for them.
Children ages 6 months to 2 years did produce the sought-after level of antibodies. The dosage was one-tenth of that given to those 12 and older, and there were no serious safety concerns, officials have said.
This month, Pfizer-BioNTech submitted a request for emergency authorization, and the FDA scheduled a meeting of its outside advisory committee for Tuesday, saying it hoped to get a head start on vaccinating young children with two shots, probably adding a third later.
Then, late Thursday, Pfizer alerted the FDA that it had more recent data, from mid-January on, showing a more discouraging picture as the omicron variant bore down. The new data revealed that two doses were not sufficiently effective in preventing symptomatic infection. The illness was generally mild and no children were hospitalized, according to people familiar with the study.
In a call with reporters Friday, Dr. Peter Marks, the FDA’s top vaccine regulator and an advocate of the two-dose strategy, said the latest data had forced a new reckoning. “Yes, some of this was late breaking,” he said, “but that’s what our job is — to adjust to it.”
Although many pediatric experts had been sympathetic to the FDA’s initial push to consider two doses, some on Friday said the regulators were right to hold off.
“I honestly let out a woo-hoo of elation that reason and science had prevailed, and that they actually really did do the right thing,” said Dr. James Conway, a pediatric infectious disease expert at the University of Wisconsin-Madison and a fellow of the American Academy of Pediatrics.
Conway said he had been concerned that prematurely authorizing a partial vaccine regimen for young children without compelling data would have intensified suspicion among some Americans that the federal government had cut corners.
At least several members of the FDA’s outside advisory panel were skeptical of the two-dose plan for the children younger than 5, and it was not clear that the panel would have recommended it.
The panel’s advice is not binding, but the FDA usually follows it.
The meeting scheduled for Tuesday had been expected to focus on just how urgent a priority the FDA and its outside advisers consider vaccination to be for the youngest age group. Dr. Ofer Levy, a pediatrician at Harvard Medical School and member of the FDA advisory committee, on Friday said the agency would have been criticized no matter how it ruled.
“They’re under intense pressure,” he said. “I don’t envy them.”
Some infectious-disease experts have argued there was not enough of an emergency to justify the FDA’s push to authorize two doses, given the combination of the trial results, the decline in omicron cases in many parts of the country and the fact that young children are unlikely to become severely ill from the virus.
Others argued that the toll of the virus on children required the FDA to jump-start its review process. Nearly 400 children younger than 5 have died of COVID-19 since the beginning of the pandemic. Even if omicron is fading, those experts argued, another variant could emerge as a new threat just as unexpectedly as omicron did in November.
Children have been more at risk during the omicron wave, pediatricians have said.
Dr. Kristin Moffitt, a physician at Boston Children’s Hospital, said that as more young children showed up in hospitals this winter, many of those she saw in her hospital were more prone to severe illness because they had existing health conditions, including congenital heart disease or immune deficiencies.
“Those with underlying conditions tended to be more severe and require ICU care,” she said. “The majority needed a couple of days of oxygen supplementation, as well as help staying hydrated.”