The Food and Drug Administration authorized booster shots of the Pfizer vaccine Tuesday for children ages 5-11, the latest in a series of actions intended to bolster waning protection against infection from the coronavirus vaccines.
More than 8 million of the 28 million children in that age group in the United States have received two vaccine shots and will now be eligible for the extra dose at least five months after their second shot. The Centers for Disease Control and Prevention is considered highly likely to recommend the booster dose after an advisory committee of outside experts meets to discuss it Thursday.
That would make all Americans 5 and older eligible for a booster shot. But booster uptake has been much slower than public health experts hoped. Many parents have been reluctant to vaccinate children in this age group at all.
Although they have been eligible for COVID-19 shots since November, only 29 percent of 5- to 11-year-olds have received two doses. Another 6 percent or so have received one shot.
In a statement, Dr. Robert Califf, the FDA’s commissioner, said, “While it has largely been the case that COVID-19 tends to be less severe in children than adults, the omicron wave has seen more kids getting sick with the disease and being hospitalized, and children may also experience longer term effects, even following initially mild disease.”
Some experts have suggested that because children 5-11 received a much lower initial dose than older children or adults, they are particularly in need of a booster shot. One study done by New York researchers found that for children 5-11, the Pfizer vaccine’s effectiveness against infection fell to 12 percent from 68 percent by four to five weeks after the second dose.
Another CDC study stated that two Pfizer doses reduced the risk of Omicron infection 31 percent among those 5-11, compared with a 59 percent reduction in risk among those 12-15.
The shot from Pfizer and its German partner, BioNTech, is the only vaccine available to children in this age group.
Dr. Peter Marks, the FDA’s top vaccine regulator, said that “emerging data suggest that vaccine effectiveness against COVID-19 wanes after the second dose of the vaccine” in all age groups.
The newly authorized booster dose is the same strength as the first two shots. In a news release, Pfizer said its clinical trial data showed that the additional shot produced a strong immune response in the age group, generating neutralizing antibodies against both the Omicron variant and original version of the virus.
The FDA said its decision was based on laboratory measurements of the immune responses in 67 children. A month after the booster dose, their levels of virus-blocking antibodies were higher than they were before the shot, the agency said. Pfizer’s trial includes 4,500 children in this age group.
In January, the FDA authorized a booster of the vaccine for adolescents ages 12-15.
Tuesday’s move may sharpen some parents’ frustration about the divide between children who can get a third shot and those who can’t yet get one. Children younger than 5 still lack access to any vaccine. A top FDA official predicted in an interview that the first shots might become available in June, assuming data supports such a move.
In late April, vaccine maker Moderna asked the FDA for emergency authorization for its two-shot coronavirus vaccine for children 6 months to 5 years old. Pfizer and BioNTech are expected to submit the full data on a three-dose regimen for children 6 months to 4 years old in coming weeks.
The FDA has set aside several dates — June 8, 21, and 22 — to meet with its outside vaccine advisers, the Vaccines and Related Biological Products Advisory Committee, to discuss applications for pediatric vaccines.
The FDA also announced plans to meet June 7 with its advisers to talk about an emergency authorization request for a coronavirus vaccine made by Novavax for people 18 and older. A vocal group of investors and some people who say they prefer the more traditional vaccine technology have been pushing for access to that vaccine for months.
Novavax submitted an application for emergency use authorization in late January. The vaccine uses a protein-based technology, with some novel twists. The vaccines from Moderna and Pfizer-BioNTech are produced using a new messenger RNA technology.
In addition, the FDA said it will convene an advisory committee meeting June 28 to discuss whether the composition of coronavirus vaccines should be modified for use in a potential coronavirus vaccination campaign this fall.
Many experts say vaccines for the general population should be reformulated to keep up with the changing virus, but the question of whether, when, and how to do that remains unresolved.
Material from The Washington Post was used in this report.