Pfizer Inc and BioNTech SE on Tuesday said they have begun submitting data to U.S. regulators seeking emergency use authorization (EUA) of their COVID-19 vaccine for children under age 5, despite weaker-than-expected immune responses in their clinical trial of 2- to 4-year-olds.
The companies said they started the rolling submission of data following a request from the U.S. Food and Drug Administration in order to address an urgent public health need in the age group.
The FDA said an outside committee of expert advisers would meet on Feb. 15 to discuss the authorization.
“Having a safe and effective vaccine available for children in this age group is a priority,” Acting FDA Commissioner Janet Woodcock said. She said the agency asked for the application because of the recent Omicron surge.
If the FDA authorizes the vaccine after its advisory panel meeting, the U.S. Center for Disease Control and Prevention also needs to sign off on how the vaccinations will be implemented, following a meeting of its own advisers. Those meetings have tended to follow within a week or so of FDA decisions.
The drug companies said they are asking the FDA for authorization of the first two doses of a planned three-dose regimen.
“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,” Pfizer Chief Executive Albert Bourla said.
He said the company believes three doses of the vaccine will be needed “to achieve high levels of protection against current and potential future variants.”
The companies expect to complete submitting data for the EUA in the coming days, with data on the third dose to follow.
Pfizer and BioNTech are testing a 3-microgram dose of the vaccine in the age group, compared with a 10-microgram dose in 5- to 11-year-olds and 30 micrograms for people aged 12 and older.
The companies said they expect to have ample supply of the 3-microgram shots should the FDA authorize the vaccine.
EVIDENCE OF CLINICAL BENEFIT?
Authorization of a vaccine for younger children could help harried parents who have had to contend with quarantines and closures of pre-schools and daycare centers.
The move could speed up the inoculation timeline for U.S. children this age by months. If a third dose is eventually authorized, many children could already have begun the regimen. Pfizer is currently testing two doses three weeks apart, followed by a third dose at least 8 weeks later.
In December, Pfizer said it was amending its clinical trial to test a three-dose version of the vaccine because the lower-dose generated an immune response in 2- to 4-year-olds that was inferior to the response measured in those aged 16 to 25. In 6- month- to 24-month-old children, the vaccine generated an immune response in line with 16- to 25-year-olds.
“The appropriateness of any EUA for under 5 for the vaccine will depend on what the data show beyond the antibody levels, for example any evidence of a clinical benefit,” said Dr. Walid Gellad, a professor at the University of Pittsburgh medical school.
The vaccine is already approved for emergency use in children in the United States as young as 5. It has full approval for adults.
The FDA also has authorized a third booster dose of the Pfizer/BioNTech shot for adults and children aged 12 and older. It gave the green light for a two-dose vaccine for children ages 5 to 11.
It remains unclear how many parents will choose to vaccinate their younger children.
Vaccinating children has been slow in the United States with only around 22 per cent of 5- to 11 year-olds having received two shots since the campaign to inoculate that age group began in November.
(Reporting by Susan Heavey and Michael Erman; Editing by Bill Berkrot and Howard Goller)