Q&A: Lingering questions about Pfizer's pediatric COVID-19 vaccine

Pfizer and BioNTech’s pediatric COVID-19 vaccine received emergency use authorization from the FDA on Friday for children aged 5 to 11 years, to be given in two 10 µg doses given 21 days apart.

The CDC’s Advisory Committee on Immunization Practices will meet on Tuesday to discuss federal clinical recommendations for the vaccine.

A larger dose of the vaccine is already fully approved for people aged 16 years or older and has been available under an EUA for children aged 12 to 15 years since May. The White House previously announced plans for a nationwide campaign to roll out and promote the pediatric vaccine for kids aged 5 to 11 years.

We asked Henry H. Bernstein, DO, a professor of pediatrics at the Zucker School of Medicine at Hofstra/Northwell, a pediatrician at North Shore University Hospital in Manhasset, New York, and an ex officio member of the AAP’s Infectious Disease committee, some lingering questions about the vaccine.

Healio: What should parents know about the risk for myocarditis from these messenger RNA vaccines?

Bernstein: We know that in the mRNA vaccines, the observed rate of myocarditis following vaccination exceeded the expected rate, and it was more common in males after the second dose. The most important aspect of it is that it was relatively mild. The studies that Pfizer presented to the FDA had more than 3,000 subjects in its study for safety and no cases of myocarditis were identified. Of course, myocarditis is a very rare adverse event that has been seen with the mRNA vaccines. So, we don't know for sure what the incidence of myocarditis will be in 5-to-11-year-olds but based on data from older children and young adults, the idea that it's mild, if it occurs at all, is very likely. People also suggest that what's been seen in older teens and adults may well be related to hormones and it would be a lower incidence of myocarditis in children aged 5 through 11 years.

I’d like to add that the safety monitoring surveillance in the U.S. is truly historic, that there are multiple systems for safety surveillance that are underway — systems that have lots of experience and are incredibly helpful in monitoring the vaccine and any effects associated with the vaccine. Parents should sign their children up when they get the vaccine for something called v-safe, which is a cell phone-based safety monitoring system that monitors side effects daily for a week, then weekly for the first 6 weeks, and then 3 months, 6 months and 12 months after the vaccine.

Healio: Do you believe that children who receive Pfizer's pediatric vaccine will eventually need a booster?

Bernstein: We don't have information about that. It would not be a surprise given that this is a respiratory virus that is capable of mutating. But certainly, there has been the question in older children and adults relating to the need for boosters and whether they are effective or not in preventing infection. Most importantly, does it prevent hospitalization and admission to the ICU or death? At this point, we don't have data that suggest that they'll need boosters, but it would not be a surprise down the line.

Healio: What should providers and pediatricians expect once these vaccines are available?

Bernstein: We would hope that pediatric providers, child health professionals are supporting the need for COVID-19 vaccines in this age group. They should understand that the volume of the vaccine itself will come in a different vial than the vial that's used for those aged 12 years and older. It'll have a different color top, the dose volume is only two-thirds of the dose used for children aged 12 years and older and the amount of antigen in it is only one-third of the dose used for children aged 12 years and older. So that could create a bit of confusion for some people, but they should understand that it's a lower amount of antigen being administered. Side effects have been the same, if not a little bit lower. And providers should feel confident that the vaccine is a little more than 90% effective against infection and then severe disease.

Healio: With that said, do you anticipate confusion about the different size of the dose?

Bernstein: It's always possible. But the fact that the vial has a different color cap and the volume of the dose that's being administered to children is lower than the dose given to those aged 12 years and older, I would hope that would reassure providers and minimize any confusion they may have.

Healio: Do you think pediatric vaccinations will expedite the end of the pandemic?

Bernstein: I do think that it really will make a big difference. Unfortunately, in this age group, we've had close to 2 million cases. There have been more than 8,000 hospitalizations, and there have been more than 5,000 cases of multi system inflammatory syndrome in children (MIS-C), with half of them in this particular age group. The idea that we could minimize the number of cases of MIS-C by getting this age group vaccinated is important to convey, too.

Although the number of deaths in this age group in comparison to adults is notably smaller, it is still in the top 10 causes of death in this pediatric age group, and honestly, any pediatric deaths is too many. People need to understand that this is now a vaccine-preventable disease, like many of the other diseases that affect children. This is a vaccine-preventable disease, and so the only way to prevent the disease is to be is to be vaccinated.