Health

Tracking the FDA advisory panel meeting on Covid-19 vaccines for kids


The moment some parents have been anxiously awaiting for months is almost here: The Pfizer-BioNTech Covid-19 vaccine for children aged 5 to 11 will likely be authorized for use in the next week, after completion of a four-step process that begins today.

It is also a moment some portion of parents has been dreading for months. And over the weekend, they made their concerns known to experts on the Food and Drug Administration’s vaccines advisory committee, which meets today to review the evidence on the Pfizer vaccine’s safety and efficacy in kids ages 5 to 11. Members of the the Vaccines and Related Biological Products Advisory Committee (VRBPAC) were deluged by an organized email campaign urging them not to recommend the vaccine.

“Over the weekend I was getting about one email every minute,” said VRBPAC member Paul Offit, a vaccines expert at Children’s Hospital of Philadelphia, who said by the time the weekend was over he had received “hundreds and hundreds.”

advertisement

Offit and colleagues on VRBPAC will meet all day to review the data and are scheduled to vote at the end of the day on whether, in their estimation, the benefits of the vaccine outweigh the risks for this group of children. If authorized, the Pfizer vaccine will be the first pediatric Covid vaccine.

The FDA is not bound to follow VRBPAC’s advice, though it often does, and disregarding it on an issue as sensitive as authorizing a Covid vaccine for children would make for a problematic launch of the program to vaccinate 5- to 11-year-olds. While the committee’s vote may not be unanimous, it is unlikely to vote against authorizing this vaccine for children.

advertisement

A day or so after VRBPAC votes, the FDA is expected to issue an emergency use authorization for the Pfizer vaccine. Step three of this process is having advisers to the Centers for Disease Control and Prevention review the vaccine’s safety and efficacy and vote on whether CDC Director Rochelle Walensky should recommend its use. The Advisory Committee on Immunization Practices meets next Tuesday, Nov. 2. If it advises Walensky to recommend the vaccine, the CDC director is likely to do that within hours, allowing the vaccination of 5- to 11-year-olds to begin as early as Nov. 3. There are already 16 million doses of the pediatric vaccine available — with more to come — for states to order and they have been ordering it, though shipping won’t begin until the FDA issues the authorization.

Matthew Herper and I will be live-blogging today’s VRBPAC meeting, which begins at 8:30 a.m. ET. You can watch it here. We will be posting our updates and analysis below in reverse chronological order; check back often.

— Helen Branswell

Some context for today’s discussions

7 a.m.: The Pfizer-BioNTech vaccine is the only one of the U.S.-deployed Covid vaccines that can be used by people down to the age of 12. Anyone 12 and older gets the same dose of vaccine, on the same regimen — two 30 microgram shots given 21 days apart.

But for younger children, the FDA required the company to conduct additional tests to determine the safety and efficacy of the vaccine in children. Pfizer tested three doses: 10 micrograms, 20 micrograms and 30 micrograms. It is seeking emergency authorization for the 10-microgram dose, which is one-third as much vaccine as is given to adults. The company said Friday that the children’s dose was 91% effective at preventing symptomatic Covid-19 in this age group.

Side effects were generally similar to those reported by adults who got the Pfizer vaccine — things like headaches and fevers.

One of the hallmarks of an FDA review is that the agency doesn’t just take the word of a would-be manufacturer of a vaccine or drug; its staff reanalyze the original data to ensure the FDA agrees with the claims the company seeking a license or emergency authorization is making.

Matt reviewed the FDA’s analysis, which was released Friday night. The agency’s scientists concluded the protection offered by the vaccine would definitely outweigh any risk of myocarditis — inflammation of heart muscle — that the vaccine appears to trigger rarely in some teens and young adults, mostly males. The cases seen after use of the vaccine appear to be milder than regular myocarditis and of shorter duration. At least in teens and young adults, Covid infection is far more likely to trigger myocarditis than the vaccine is, according to research from Israel.

The Pfizer study compared 1,518 children who received the vaccine to 750 children who received a placebo. There were three cases of symptomatic Covid among the former and 16 among the latter. The vaccinated children who contracted Covid had very mild symptoms; none had fever. But 10 of the 16 unvaccinated children had fevers and symptoms were more pronounced overall in the placebo group.

The FDA analysts used mathematical modeling to estimate how many hospitalizations would be prevented by vaccinating a million boys in the 5 to 11 age range at six different points in the pandemic in the United States. At most points, the vaccine would prevent 200 to 250 hospitalizations per one million vaccinated boys. But when transmission of the SARS-CoV-2 virus was low, as it was in June 2021 — before the spread of the Delta variant — the vaccine would only have prevented only 21 hospitalizations per one million boys, the agency’s model suggested.

That meant, the FDA said, that at times of low transmission the vaccine might trigger slightly more myocarditis-related hospitalizations in boys than Covid-related hospitalizations it prevents. But even then, it said, the benefits may still outweigh the risks, because the myocarditis cases are mainly mild and the Covid cases that require hospitalization are more severe.

The need to balance the vaccine’s benefits versus the risks of myocarditis is likely to be the key issue of today’s discussions. At least one VRBPAC member, Tufts Medical Center pediatrician Cody Meissner, has been indicating for months that he has serious concerns about using the vaccine in people who are at lower risk of developing severe disease if they contract Covid. Kids definitely fall into that category, so Meissner will likely be vocal today.

— Helen Branswell


Most Related Links :
Business News Governmental News Finance News

Source link

Back to top button