The Centers for Disease Control and Prevention on Thursday signed off on booster shots of the Pfizer-BioNTech Covid-19 vaccine for children ages 5 to 11.
The final endorsement, from CDC Director Rochelle Walensky, came hours after the agency's Advisory Committee on Immunization Practices voted 11-1, with one abstention, in favor of giving 5- to 11-year-olds the boosters at least five months after their second dose.
"Today, I endorsed ACIP’s vote to expand eligibility for Covid-19 vaccine booster doses," Walensky said in a statement. "Children 5 through 11 should receive a booster dose at least 5 months after their primary series."
Vaccination rates for children 5-11 in the U.S. have "lagged behind other age groups leaving them vulnerable to serious illness," Walensky said. Less than 30 percent of the 28 million kids in this age group have received two doses of a Covid-19 vaccine, according to data from the CDC.
While children are generally less likely than adults to get seriously ill from Covid, some do: more than 15,000 children ages 5 to 11 have been hospitalized and at least 189 of them have died, CDC data shows.
The panel convened two days after the Food and Drug Administration authorized booster shots for this age group.
Clinical trial data presented by Pfizer representatives at Thursday's meeting showed a 10 microgram booster dose for children 5-11 — a third of the dosage given to people 12 and up — raised antibody levels against both the omicron variant and the original strain of the coronavirus, which has long been out of circulation.
The omicron variant tore through the pediatric population this past winter, even among the vaccinated. In February, researchers from the New York State Department of Health reported that two doses of the Pfizer vaccine offered little protection against infection for children 5-11 during the omicron wave, though the CDC found it did still protect against severe illness.
A recent CDC report found that roughly 75 percent of children 11 and under had evidence of an infection by February, up from 44 percent in December.
The high infection rate among children led some committee members to consider whether two doses of the vaccine plus an infection obviated the need for a booster shot at this time.
“Could it not be that their original exposure and two doses would give them that full immunity that we’re looking at?” said committee member Dr. Helen Keipp Talbot, a professor of medicine at Vanderbilt University and the sole "no" vote.
Dr. Sara Oliver, an epidemic intelligence service officer for the CDC, presented data at Thursday’s meeting that showed that during the winter omicron surge, unvaccinated children in this age group were twice as likely to be hospitalized than those who received the two-dose series.
"As a mother and an infectious disease specialist and a member of ACIP, if my children were still in this age cohort, I would give my children this booster," said committee member Dr. Camille Kotton, an infectious disease clinician at Massachusetts General Hospital in Boston.
Committee member Dr. Matthew Daley, a senior investigator at Kaiser Permanente Colorado, argued that the third dose should be considered as part of a three-dose primary series and not a booster dose.
That's because, he said, many vaccinations that are given in early childhood for other viruses, such as hepatitis B and rotavirus, usually require multiple doses.
The decision to make boosters available to 5- to 11-year-olds comes as Covid vaccinations have slowed to a crawl, particularly in children.
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While vaccinated children should be allowed to get an additional dose, there should be a bigger push by public health officials to get unvaccinated children their first two shots, said committee member Dr. Sybil Cineas, the associate program director for the Brown Combined Internal Medicine-Pediatrics Residency Program.
“As a primary care provider, it’s hard for me to be having a discussion about these sorts of issues when only 28 percent have their primary series,” Cineas said.
Only children younger than 5 remain ineligible for Covid vaccines, a sore spot for many parents and doctors across the country eager to vaccinate their youngest.
Committee member Dr. James Loehr, a family physician from Ithaca, New York, took an opportunity during the meeting to urge regulators to expedite the Covid vaccine review for these children.
Dr. Doran Fink, a deputy director of the FDA's division of vaccines, told the committee that regulators are working quickly to review the data.
Fink said Moderna's vaccine application to the FDA for children ages 6 months to 5 years was completed "just recently," and the agency is working to bring the request to its advisory committee as "rapidly as we can." A final decision on that vaccine is expected in June.