Pfizer Inc. announced Tuesday that it has asked the U.S. Food and Drug Administration to authorize its two-dose COVID vaccine for emergency use in children under 5 while it continues to research the power of a third shot in these youngest Americans.

If the FDA grants the request, the two-shot regimen would become the first approved for use in children this young; older children are already eligible for the vaccine. In December, Pfizer suffered a setback when it announced that two doses of the vaccine, which are one-tenth the amount of an adult dose, did not produce a sufficient immune response in children aged 2 to 4. The company has already started testing a third dose for this age group.

“As hospitalizations of children under 5 due to COVID-19 have soared, our mutual goal with the FDA is to prepare for future variant surges and provide parents with an option to help protect their children from this virus,” Pfizer Chairman and CEO Albert Bourla, said in a company statement announcing the move.

“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,” Bourla added. “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.”

It is a strategy federal regulators have encouraged as they have been eager to review Pfizer’s data in hopes of authorizing shots for young children as early as the end of February, multiple people familiar with the discussions told the Washington Post. If Pfizer waits for data on three doses, the request would not be submitted until late March.

“We know that two doses isn’t enough, and we get that,” one of the people familiar with the situation told the Post. “The idea is, let’s go ahead and start the review of two doses. If the data holds up in the submission, you could start kids on their primary baseline months earlier than if you don’t do anything until the third-dose data comes in.”

Last Friday, Pfizer briefed federal health officials on updated trial data on the shots, an administration official who spoke on the condition of anonymity, told the Post.

Those attending the briefing included Dr. Anthony Fauci; David Kessler, chief science officer for the government’s COVID-19 response; a representative from the U.S. Centers for Disease Control and Prevention; and other officials from the U.S. Department of Health and Human Services, the Post reported.

The session included a “robust conversation” that three doses were likely to be much more powerful than just two shots, the administration official said. “But to get to three, you have to get two shots first. … There’s interest in seeing this move forward,” the official told the Post.

In that vein, an FDA advisory panel will weigh the two-dose regime on Feb. 15.

But at least one panel member voiced concerns about the highly unusual “rolling authorization.”

Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, suggested that regulators could be short-circuiting the normal process without a clear rationale.

“It doesn’t make sense we would approve a two-dose vaccine on the assumption the third dose would make up for deficiencies of the two doses,” he told The New York Times.

The deficiencies were significant: One person familiar with the data, who spoke on condition of anonymity, told the Times that children aged 2 to 4 who were given two shots were infected at a rate 57 percent lower than the children who were not, and those between the ages of 6 months to 2 years old who got shots were infected at a rate 50 percent lower than those who were not. There were fewer than 100 cases of symptomatic infection — a small fraction of the participants overall — and the margins of error were wide, the person noted.

FDA panel member Dr. H. Cody Meissner, chief of the pediatric infectious diseases division at Tufts Children’s Hospital in Boston, said he was willing to weigh the “rolling authorization” strategy but he worried that rare side effects might be missed in the small-scale trials conducted so far.

The panel’s decision “will partly depend on what are the rates of hospitalization and severe disease in this age group, and what our sense is in terms of potential harm” should the two-dose regimen be authorized, Meissner added.

But Acting FDA Commissioner Dr. Janet Woodcock and Dr. Peter Marks, who oversees the agency’s vaccines office, said Tuesday that it was important to act quickly given the surge in Omicron cases and the likelihood that other variants will follow.

“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,” Marks said in an agency statement.

As the Omicron variant has spread, there has been a steep increase in pediatric cases of the virus, according to the American Academy of Pediatrics (AAP), which gathers state-level data. Even though most young children tend to do well combating the virus, some can get very ill.

AAP President Dr. Moira Szilagyi said in a statement on Tuesday that she was encouraged that “we may be one step closer” to shots for the youngest children.

Last month, “we reported the highest number of COVID-19 cases among children since the pandemic’s onset. More than 3.5 million new cases in children were reported in January 2022 alone,” she told the Times.

If the two-dose regimen is authorized, not every parent is going to race to their pediatricians office for shots, according to a new survey from the Kaiser Family Foundation: Only 3 in 10 parents of children under 5 said they plan to get their children vaccinated as soon as shots become available.

More information

Visit the U.S. Food and Drug Administration for more on COVID vaccines.

SOURCE: Pfizer, news release, Feb. 1, 2022; U.S. Food and Drug Administration, news release, Feb. 1, 2022; The New York Times; Washington Post

Source: HealthDay

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