Food and Drug Administration advisers voted Wednesday to recommend authorizing both Moderna and Pfizer-BioNTech’s Covid-19 vaccines for young children, clearing one of the final hurdles to getting the youngest Americans vaccinated.
The Vaccine and Related Biological Products Advisory Committee held a vote for each vaccine during its Wednesday meeting. Both recommendations were unanimous: 21-0.
Moderna’s vaccine is for children ages 6 months to 5 years, while Pfizer’s is for children ages 6 months to 4 years.
The committee’s recommendations are not the final signoff needed to administer the shots, but the votes will now set in motion a fast-moving process expected to be completed by Tuesday — a great relief to parents who have waited more than a year-and-a-half to vaccinate their youngest.
The decision will now go to the FDA, which is expected to grant emergency use authorization to the vaccines in the coming days. On Friday and Saturday, an advisory panel to the Centers for Disease Control and Prevention is expected to vote on whether to endorse the shots. The final step is signoff from CDC Director Dr. Rochelle Walensky — then, shots in arms (or thighs).
The votes represent, in a sense, the culmination of more than a year and half of work from the committee. VRBPAC held its first meeting about Covid vaccines on Dec. 10, 2020. Its decision at that time was to recommend the Pfizer vaccine for people ages 16 and up. With Wednesday's vote, lowering the age of vaccination down to 6 months, everyone will soon be eligible.
"I'm really pleased that we've reached this kind of milestone," said Dr. Ofer Levy, the director of the Precision Vaccines Program at Boston Children’s Hospital.
Despite the celebratory mood of the committee, members of the panel acknowledged the heightened emotions surrounding vaccinating young children. During a particularly heated public comment period, parents and other members of the public advocated passionately both for and against the vaccine.
Clear communication to parents and guardians about the vaccine will be incredibly important, the panel said. And nearly all of the committee members, which includes pediatricians, infectious disease doctors and vaccine experts, mentioned during the discussion that the decision for parents to vaccinate children in this age group should be a choice.
Though younger children are usually spared the worst effects of Covid, severe cases and deaths can still occur. This was particularly apparent this past winter, when the omicron wave sent the hospitalization rate of children under 5 higher than any previous point in the pandemic, according to CDC data.
Committee member Dr. Jay Portnoy, a professor of pediatrics at Children’s Mercy Hospital in Kansas City, Missouri, described walking by his hospital’s emergency room earlier this year and seeing it filled with Covid patients.
“I know that the death rate from Covid among young children may not be extremely high,” Portnoy said. “But it’s absolutely terrifying to parents to have their child be sick and have to go to the hospital or even go to the emergency room or their primary care doctor because they’re sick and having trouble breathing.”
As of May 28, at least 442 children under 5 have died due to Covid, Dr. Peter Marks, the FDA’s top vaccine regulator, told the committee. That number of deaths, over the course of just over two years, is far higher than what’s typically seen over the same time period for other dangerous respiratory viruses, such as influenza, he said.
Children are also susceptible to a rare complication of Covid called MIS-C, or multi-system inflammatory syndrome in children, which causes severe inflammation throughout the body.
Even so, the panel acknowledged that the risk of these severe outcomes is very small — the vast majority of children with Covid recover.
Two vaccines available for children
Clinical trial data presented by both Moderna and Pfizer representatives at Wednesday’s meeting showed the vaccines were safe and effective in the youngest kids.
Moderna’s vaccine consists of two shots, given four weeks apart. The tot-size doses are 25 micrograms — a quarter of the dosage given to adults. The shots were around 40 to 50% effective at preventing milder omicron infections in young children.
Acknowledging the lower efficacy, Moderna said it expects children in the age group to be offered a booster dose of the vaccine “at some point in time.”
Pfizer experienced similar problems to Moderna earlier this year when clinical trials found its two-dose regimen provided only limited protection against infection.
At Wednesday’s meeting, Pfizer presented data on three doses of the vaccine, which were shown to be 80% effective in preventing symptomatic Covid. The first shots are given three weeks apart, followed by the third shot, eight weeks later.
Pfizer’s shot for children under 5 is also a lower dosage than its version for adults: 3 micrograms versus 30 micrograms.
Dr. Amanda Cohn, chief medical officer at the CDC’s National Center for Immunization and Respiratory Diseases, cautioned against comparing the efficacy numbers of the two vaccines, given that they were based on only a small number of Covid cases.
“I believe the vaccine is effective,” she said.
Both the Moderna and Pfizer vaccines were shown to be generally well tolerated in children, with similar side effects, which included pain at the injection site, irritability, drowsiness and fever.
In an analysis published online over the weekend, FDA scientists said the pediatric trials may have been too small to detect a rare heart inflammation condition called myocarditis.
The Moderna and Pfizer vaccines have been linked to rare instances of myocarditis, particularly in teen boys and young men, though no cases were seen in the trials for the youngest children.