Pfizer and BioNTech said Tuesday that they were seeking emergency-use authorization for the first coronavirus vaccine for children younger than 5 and have begun submitting data on the safety and efficacy of the first two doses of a planned three-dose regimen.
“In light of these new data and the rise in illnesses and hospitalization in this youngest age group, FDA believed that it was prudent to request that Pfizer submit the data it had available, including the data that it has recently collected during the omicron surge,” Caccomo said.
The latest data has not yet been published or peer-reviewed, and the companies did not summarize it in their announcement. The updated trial data will become public when the FDA issues its briefing book on the authorization request in advance of a scheduled Feb. 15 meeting of its outside advisers.
The briefing documents, which will also include the agency’s view of the data, are expected to be posted next week. A person familiar with the situation suggested that the company is reluctant to release the data in advance of the briefing documents because new information about the vaccine in young children keeps coming in.
The person, who spoke on the condition of anonymity because they were not authorized to discuss the matters publicly, said the data the FDA already has shows that the vaccine is safe in young children and has clinical efficacy — meaning it prevents cases of covid-19.
In December, Pfizer and BioNTech announced that the immune response generated by the vaccine in children between 2 and 4 years old was not sufficiently robust. But the companies said the vaccine had provoked a strong enough response in children 6 months to 2 years old. A third shot was added to the trial to increase the immune response.
An earlier vaccine trial in children 5 to 11 years old was also focused on showing that those children had adequate immune responses after vaccination. In addition, there were enough cases of illness in that study population to determine that the vaccine was 91 percent effective in preventing symptomatic illness.
The companies said Tuesday that the FDA requested they move forward with an application because of the “urgent public health need in this population,” noting that 1.6 million children under the age of 4 have tested positive for the coronavirus.
“Ultimately, we believe that three doses of the vaccine will be needed for children 6 months through 4 years of age to achieve high levels of protection against current and potential future variants,” Pfizer chief executive Albert Bourla said in a statement. “If two doses are authorized, parents will have the opportunity to begin a COVID-19 vaccination series for their children while awaiting potential authorization of a third dose.”
A committee of outside advisers is expected to meet to review the data in two weeks, a process that will influence but not determine the decision that the agency makes. A similar advisory committee to the Centers for Disease Control and Prevention will also scrutinize the data. The vaccine could become available by the end of February.
“The need for a safe and effective vaccine for our youngest children is significant, particularly given the rapid spread of the omicron variant, the notable rise in the number of hospitalizations in young children with severe disease, and the possibility that future variants could cause severe disease in those who are unvaccinated,” Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said in a statement.
The application for a two-shot regimen, months earlier than the companies had predicted, is being celebrated by some parents eager to protect their children from the virus. There are about 18 million children under the age of 5 in the United States, according to the FDA. The vaccine is being tested in children as young as 6 months.
But those parents appear to be a modest fraction of all families. A poll by the Kaiser Family Foundation found that only 3 in 10 parents of children in the age range said they would get their children vaccinated right away if a vaccine were authorized, and a quarter of parents said they would “definitely not” vaccinate their young children. The poll of 1,536 adults was conducted between Jan. 11 and 23.
Uptake of the vaccine has been slow among 5-to-11-year-olds who became eligible for the shot in early November, with 70 percent remaining unvaccinated, according to a Kaiser analysis.
Pfizer and BioNTech are testing a three-microgram dose of the vaccine in the youngest children, one-tenth the dose given to adults. In December, they announced the children’s vaccine would be delayed because the immune response in 2-to-4-year-olds was not equivalent to the protective response in teens and young adults. The news was a major blow to parents and pediatricians. Adding a third shot to increase the level of protection meant results would be delayed until the end of March.
“Getting the ball rolling, to get kids vaccinated — if we start now, and we still need to give them more doses, that’s okay,” said Sharon Nachman, chief of the division of pediatric infectious diseases at Stony Brook University Hospital. “With omicron and the increase in hospitalizations in children, it’s probably a good idea to start vaccinating children, recognizing we may need to do another dose.”
Although covid-19 is typically less severe in children, the enormous toll of the omicron surge has not spared the youngest. So far this year, there have been 12 deaths of children under the age of 5 in the United States, according to the CDC — and 280 deaths in that age group since the beginning of the pandemic, representing a small fraction of the more than 884,000 deaths overall in the nation.
“Pediatricians have seen firsthand the fear, stress and hardship that so many families of young children have endured as they await a vaccine. We urge a transparent and data-driven process to evaluate this vaccine for this age group and look forward to offering its protection to our youngest children,” Moira A. Szilagyi, president of the American Academy of Pediatrics, said in a statement.
Nachman said it would be important to see the data on the vaccine’s performance in the youngest children — and to understand the extent of the inadequate immune response generated in some children.
“Was it a huge miss or a small miss? And what time frame did they look at the miss? Is some protection better than no protection?” Nachman said.
If the vaccine were authorized within weeks, children would probably begin to get their first shots as the omicron surge is expected to be lifting. They would also begin to build immunity that might offer protection against future variants.
The dilemma is a textbook study of the difficulty of regulatory decision-making in a crisis. The children’s trial had been designed to test whether a lower-dose vaccine created an immune response equivalent to or greater than the one that protected young adults — something measured in a laboratory. But because of the omicron surge, enough cases of covid-19 occurred among study participants to provide evidence that the vaccine was protecting children against illness, though details were not available Tuesday.
“It’s not fair we are keeping them from getting something that we know would work, even if it is not the best [protection] with two doses,” said Flor Munoz, associate professor of pediatrics at Baylor College of Medicine.
Emily Guskin and Dan Keating contributed to this report.
A previous version of this article incorrectly stated the number of children under the age of 5 in the United States is 23 million, because of to an error by the Food and Drug Administration. It is 18 million. The article has been corrected.
