October 26, 2021 – The benefits of Pfizer’s COVID-19 vaccine for children ages 5 to 11 outweigh its risks, according to an independent panel of vaccine experts advising the FDA.
Seventeen of 18 members of the Vaccines and Related Biologics Advisory Committee (VRBPAC) voted on Tuesday to recommend the 10 microgram vaccine for children, one-third of the adult dose.
One member, Michael Kurilla, MD, director of the division of clinical innovation at the National Institutes of Health, abstained from voting.
If the FDA follows the recommendation, as it typically does, and issues an emergency use authorization for the vaccine, the injections could be available within days.
“This is a much more difficult question than we expected,” said committee member Eric Rubin, MD, editor and chief of the New England Journal of Medicine, at the committee meeting Tuesday. Before the vote, the committee heard presentations outlining the expected benefits of immunizing children as well as its potential risks.
“Children have been greatly affected by the pandemic,” said Fiona Havers, MD, a physician at the Atlanta CDC who has examined the epidemiology of COVID-19 in children.
In the second year of the pandemic, as more older people have been vaccinated against the virus, COVID cases have largely moved from the oldest age groups to the youngest.
So far, there have been over 1.9 million cases of COVID-19 in children aged 5 to 11 in the United States. Childhood cases surged in July and August with summer travel, the reopening of schools and the dominance of the Delta variant.
And these are just the cases reported to the CDC. Regular testing of anonymous blood samples collected from sites across the United States indicates that 6 times more children have had COVID than reflected in official counts.
Last winter, tests of blood samples showed that about 13% of children had antibodies to the virus, suggesting they had been infected. This summer, that number had risen to 42%.
This figure clearly impressed many committee members who asked FDA vaccine reviewers if they had tried to factor immunity to past infections into their modeling. They hadn’t.
Some felt that even with a very effective vaccine – new data presented by Pfizer showed the children’s dose to be 90% effective in preventing symptomatic infections in children – caution was in order as much is still unknown. on heart inflammation, a rare side effect of mRNA vaccines. .
The inflammation, called myocarditis or pericarditis, was more common in younger age groups. It usually goes away with time but requires hospital care. It is not known if myocarditis could have lasting effects for those who suffer from it.
No cases of myocarditis were observed in Pfizer’s vaccine studies in children, and no other serious events were observed.
“We believe we have optimized the immune response and minimized our reactions,” said William Gruber, MD, senior vice president of vaccine research and clinical development at Pfizer.
But the studies did not include enough participants to detect rare but serious adverse events like myocarditis.
“We’re worried about a side effect that we can’t yet measure, but it’s probably real, and we’re seeing a benefit that’s not the same as in the older age groups,” Rubin said.
Benefits vs Risks
The FDA has modeled the benefits and risks to children under various scenarios. The benefits of vaccines for children depend very much on the degree of transmission in the community.
When transmission is high, the benefits to children – in terms of infections, hospitalizations, intensive care admissions – clearly outweigh its risks.
But when COVID-19 rates are low in the community, as they were in June, FDA analysts predicted vaccines could send more children to hospital for myocarditis than the virus would. .
The FDA has noted that children hospitalized with myocarditis tend not to be as sick as children with myocarditis.
“If the trends continue as they are, the emergency for children is not what we might think it would be. That was my concern, ”said James Hildreth, MD, president and CEO of Meharry Medical College in Nashville, TN.
But others cautioned against complacency.
“To think that this will definitely be the end of the wave may be a little too optimistic,” said committee chair Arnold Monto, MD, professor of public health and epidemiology at the University of Michigan.
The majority of cases of COVID-19 in children are mild. Only about 1% of children are hospitalized for their infections, according to CDC data. But child hospitalization rates are about 3 times higher for people of color – including blacks, Hispanics and Native Americans, compared to whites and Asian Americans.
Since the start of the pandemic, 94 children aged 5 to 11 have died, making it the 8the leading cause of death in children this age last year.
More than 5,200 children have developed a delayed complication of their infections called multisystem inflammatory syndrome – children, or MIS-C. MIS-C can be serious and require hospital treatment and can lead to myocarditis or inflammation of the heart muscle. Children aged 5 to 11 are the age group most at risk for this complication.
Children can also contract post-COVID conditions known as COVID long. There isn’t a lot of data on how often this happens, although it appears to be less common in children than in adults. But a survey in the UK found that 7-8% of children show symptoms of their infections that last longer than 12 weeks, Havers said. Symptoms that may persist in children include fatigue, cough, muscle and joint pain, headache, and insomnia.
More than one million children have been affected by school closures so far this year, and quarantines have had lasting effects on learning, social development and mental health.
Even though children are generally not super-spreaders of COVID, they can still pass the infection on to others.
“What is clear is that secondary transmission from children, both to other children and to adults, is occurring,” Havers said.
Because of this, they can continue the spread of the virus and give it the chance to mutate and become more dangerous.
“I am really very grateful that we had this discussion and voted to approve it,” said Captain Amanda Cohn, MD, chief medical officer at the National Center for Immunization and Respiratory Diseases. “I think the benefits in this age group are really very large even though they are lower than in other age groups.”