The Food and Drug Administration’s outside advisors voted unanimously on Wednesday to recommend that the agency authorize the Moderna and Pfizer-BioNTech coronavirus vaccines for very young children, a move that could pave the way for regulators to allow both childhood vaccines on an emergency basis at a later date. this week.
The three-dose Pfizer vaccine will cover children 6 months to 4 years old, while the two-dose Moderna vaccine will cover children 6 months to 5 years old. Countries have already requested millions of doses. Depending on what regulators do, White House officials said dose administration could begin in earnest on Tuesday.
The US Food and Drug Administration said clinical trial data from companies show that each vaccine met standards for safety and efficacy in the age group.
More than two years into the pandemic, no vaccine has been authorized for children under the age of 5 in the United States, an unmet need that has troubled many parents. The Food and Drug Administration is expected to act on the recommendations immediately, followed by the Centers for Disease Control and Prevention later this week.
The panel of advisors voted 21-0 to recommend licensing for both Moderna and Pfizer’s vaccines. “I know the death rate from Covid and young children may not be very high,” said Dr. Jay Portnoy, professor of pediatrics at Children’s Mercy Hospital in Kansas City, Missouri. Make their kids get sick” or go to the hospital.
“There are a lot of parents who are absolutely desperate to get this vaccine, and I think we owe it to them to give them the choice,” he added.
The two vaccines considered by the committee on Wednesday appeared to be significantly less effective against symptomatic infection than the adult vaccines when they were introduced. The FDA credits Omicron as being more adept at evading vaccine defenses against infection than the original version of the virus.
Given the noticeable waning of protection among adult recipients and the rapid evolution of the virus, organizers said that children who will receive the Pfizer and Moderna vaccines will likely need a booster dose. This means that the Pfizer vaccine, which was developed with Germany’s BioNTech, could end up with four doses, while Moderna’s vaccine could be three.
The Pfizer-BioNTech and Moderna vaccines raised levels of neutralizing or virus-blocking antibodies in children similar to those in adolescents and young adults 16 to 25 years old. The Pfizer vaccine has been licensed for children ages 5 to 15 since last year, and regulators said it helped prevent hospitalizations and deaths.
After two doses, Pfizer’s vaccine was only 28 percent effective in preventing symptomatic infections in children 6 months to 4 years old. Pfizer suggested the vaccine was 80 percent effective after a third dose, but the result was based on just 10 cases from a subset of 1,678 trial participants. The trial protocol specified that evaluations of vaccine efficacy are based on at least twice as many cases; The small number of cases on which the outcome of the event was based was a cause of panic among committee members and organizers on Wednesday.
Dr. Doran Fink, the chief federal vaccine regulator, described Pfizer’s efficacy data as preliminary. “We consider it inaccurate and potentially unstable,” he said. “What exactly is the efficacy of the vaccine after the third dose needs more data.”
Moderna found its vaccine to be 51 percent effective in preventing cross-infection in children 6 months to 2 years old, and 37 percent effective in children 2 through 5. These results appear to be consistent with those reported in studies conducted on adults during the omicron era, according to the U.S. Food and Drug Administration. He said. Nevertheless, immunization continues to provide powerful protection against severe illness leading to hospitalization and death.
Regulators and company officials spent part of the day discussing the side effects caused by vaccines. The vast majority were mild and tolerated by children in clinical trials: irritability, crying, drowsiness, fatigue, and loss of appetite. Fewer participants in the trial experienced fevers, but those were consistent with the effects of other childhood vaccines.
In younger age groups, fevers can be more subdued and require more urgent medical attention, a dynamic that places significant pressure on manufacturers to properly calibrate doses. Pfizer selected a dose that was one-tenth the strength of an adult dose, in three shots; The first two weeks are given every three weeks, and the third comes at least eight weeks later. Moderna used a quarter of the strength of its adult doses, in two doses, four weeks apart.
Some difficult questions remain. Importantly, neither vaccine has been tested against the subvariants prevalent in the United States. Clinical trials were largely conducted when the Omicron variant predominated. Two sub-variables, BA.4 and BA.5, can become dominant within a month.
The need to protect these children from Covid is remarkable, Dr. Peter Marks, the FDA’s top vaccine regulator, said at the meeting. He added that hundreds of children died of Covid, a rate he said “compared terribly” to child deaths during the major flu wave in 2009 and 2010.
June 15 2022
Due to an editorial error, an earlier version of this article erred when the Pfizer-BioNTech vaccine was licensed for various age groups in the United States. The vaccine was licensed for ages 16 and older in late 2020, not in 2021, when vaccines were licensed for ages 5 to 15.