The Food and Drug Administration is expected to authorize a booster shot of the Pfizer-BioNTech vaccine for children ages 5 to 11 as early as Tuesday, according to multiple people familiar with the plan. That would make those kids the youngest Americans eligible for the extra shot.
The companies announced a month ago that the additional injection significantly increased levels of neutralizing antibodies against both the original version of the virus and the Omicron variant in a small clinical trial involving 140 children. Other research has suggested that the protection against infection offered by two Pfizer injections diminishes within just a few weeks for 5- to 11-year-olds, underscoring the need for a booster dose.
A meeting of outside vaccine experts on a Centers for Disease Control and Prevention advisory committee is scheduled for Thursday. dr. Rochelle P. Walensky, the director of the CDC, is then expected to give her own recommendation about the shot.
There are more than 28 million children ages 5 to 11, nearly 40 percent of Americans under the age of 18. But since these children have the lowest vaccination rate against the coronavirus of all eligible Americans, public health experts don’t expect the driver to be in a rush. Although they have been eligible for Covid shots since November, only 28.8 percent of children in this age group have received two doses. Another six percent have received one injection.
No coronavirus vaccine is yet available for children under the age of 5, but data is coming in from both Moderna and Pfizer regarding their clinical trial results, and regulators are expected to decide in about a month whether the proposed regimens will succeed.
Currently, Americans ages 12 and older are eligible for a first booster at least five months after their second injection, and approximately 30 million people age 50 or older, as well as many people with immune deficiencies, are eligible for a second at least four months. then .
Hundreds of children aged 5 to 11 have died of Covid since the start of the pandemic, according to the Centers for Disease Control and Prevention, but many parents have been hesitant to vaccinate their children, apparently because the risk of serious illness is relatively low. The lowest vaccination coverage was in southern states.
In the Pfizer-BioNTech clinical trial, children showed a six-fold increase in antibody levels against the original version of the virus one month after receiving the booster, compared with one month after receiving a second dose. The third dose was given approximately six months after the second injection.
Laboratory tests of blood samples from a small subset of 30 children also showed 36 times the level of neutralizing antibodies to the Omicron variant compared to levels after just two doses. The study did not reveal how long the antibodies last or the effectiveness of the test against Covid-19.
Some experts have suggested that because children ages 5 to 11 were given a much lower starting dose than older children or adults, they especially need a booster shot. A study conducted by New York researchers found that for children ages 5 to 11, the effectiveness of the Pfizer vaccine against infection dropped to 12 percent from 68 percent within 28 to 34 days of the second dose. Another CDC study found that two doses of Pfizer reduced the risk of Omicron infection by 31 percent in the age group 5 to 11 years, compared with a 59 percent risk reduction in the age group 12 to 15 years.
So far, Pfizer’s vaccine is the only one approved for people under the age of 18.
Earlier this month, Moderna applied for an emergency permit for its coronavirus vaccine for children ages 6 to 11.
Moderna is seeking approval for an initial two-dose regimen, without a booster. According to a published report, participants in that clinical trial produced antibody levels slightly higher than those seen in young adults after two doses, which was considered a strong immune response.
Moderna’s trial was not large enough to assess the vaccine’s ability to prevent serious illness or death. But based on a small number of infections with the Delta variant that was dominant last summer and fall, the researchers estimated that the vaccine had 88 percent efficacy against infection.
