Explaining the Safety of the COVID-19 Vaccine for Children: The Experts Weigh In

Masked child posing in front of UVM Children's Hospital poster featuring a moose.

The Centers for Disease Control and Prevention (CDC) officially endorsed the Pfizer COVID-19 vaccine for children age five to 11. Pediatric experts Lewis First, MD, Chief of Pediatrics at UVM Children’s Hospital, and Rebecca Bell, MD, president of the Vermont state chapter of the American Academy of Pediatrics and a pediatric critical care specialist, weigh in on the safety of the vaccines for children. 

What do pediatricians think about the COVID-19 vaccine for children? 

Pediatricians love it when children feel good. When children feel good, pediatricians feel great!  We now have a vaccine that has been given to millions of teenagers and adults and to more than one million children age five to 11. And we know that the vaccine reduces hospitalizations and death. We know that the benefits of this wonderful scientific advancement far outweigh the risk.

How can we not be feeling terrific that our five to 11-year-olds are now eligible for this vaccine? Most importantly for our children, it will bring normalcy back to their lives and in turn their family lives as well. – Dr. Lewis First

Yes, we are so excited! As the delta variant has come into our communities, our vaccinated adolescents have been protected against serious disease. We are so excited that this vaccine is now available to younger children.

Parents have been eagerly anticipating the chance to protect their children through vaccination. We've all been able to see how careful and thoughtful the vaccine development and testing process has been in real-time and understand the rigor around vaccine authorization. – Dr. Rebecca Bell

Can young children have serious complications from COVID-19 infection?

Yes, they can. Although children have a lower rate of serious illness than adults, they still can get very ill from COVID-19. When infants get COVID-19 and are hospitalized, we see high fevers, evidence of inflammation and the infant doesn’t feel or feed well. They sometimes need IV hydration and other types of support. 

For unvaccinated adolescents, we're seeing really serious COVID-19 pneumonia. This can manifest as lung injury and the need for lots of oxygen to sometimes help with breathing. The recovery time can be quite prolonged, even in previously healthy adolescents. 

For unvaccinated school-aged children, we see a rare but serious complication of COVID-19 infection, something called MIS-C or multisystem inflammatory syndrome in children. Children get so sick they need to come into the hospital, typically the ICU. They might need oxygen and organ support for their heart, kidneys or other organs. There have been more than 5,500 kids across the U.S. who have met criteria for this condition.

COVID-19 infection can affect the heart – a condition called myocarditis – in which the heart can be inflamed. Unfortunately, this can affect a child or adolescent’s  ability to exercise. This really worries us. Lastly, children with acute COVID-19 infection can have blood clots and oftentimes need blood thinners. – Dr. Rebecca Bell

How do you treat children that are hospitalized with COVID-19?

We try to lessen the damage that the child's own immune system does to its body when it responds to COVID-19. We use steroids and other therapies that help control the immune system, similar to the treatment used in the adult population. – Dr. Rebecca Bell

Are children at risk of ‘long COVID’ after COVID infection?

A couple of studies suggest that 10 to 15 percent of children who experience COVID-19 will potentially experience ‘long COVID.’ It means you may or may not have some of the common, acute symptoms of this infection, but then four or five weeks later you start to feel more fatigued, have headaches, may have a cough or difficulty breathing, and you may feel like your brain is foggy. This is felt to be an ongoing inflammatory reaction to the virus that doesn’t want to go away. It may not put you in the hospital, but it will affect a child or teenager’s ability to play a sport and participate in school. 

‘Long COVID’ can last for weeks to months, and it is a complication that we can prevent through vaccination. Avoiding ‘long COVID’ another great reason to give this vaccine to our five to 11-year-olds. – Dr. Lewis First

How does the vaccine work?

All vaccines work similarly: Vaccines present information to your immune system in a controlled way, so that it can learn about a specific pathogen, virus or bacteria. By doing this, your body can build up an immune response so that your immune system has a memory about how to fight it if you're ever exposed to that virus or bacteria in the future. 

The Pfizer vaccine approved for children is an mRNA vaccine, a technology has been in place for decades. It works by giving your body a recipe so that your cells can make a harmless spike protein that looks like the virus. Without the vaccine, your body isn’t prepared to react quickly when it is exposed to the virus in the future and will be trying to build up a response while fighting the virus. The virus replicates quickly in your body and your immune system will be scrambling to catch up. – Dr. Rebecca Bell

Does the vaccine change our bodies?

No. There is no long-lasting piece of the vaccine that stays in your body. The vaccine doesn’t change  anything about the way your body works. It does not modify or alter a pathway. Instead, it presents information to your immune system and allows your body to react normally if it was exposed to a real pathogen. – Dr. Rebecca Bell

I’ve heard the COVID-19 vaccine and COVID-19 infection can cause heart issues. Which is worse?

You’ve likely heard of a condition called myocarditis, which is inflammation of the heart muscle. Common viruses like influenza, adenovirus, coxsackievirus, parainfluenza, and now COVID-19 infection, can cause myocarditis in children. Infection-induced myocarditis can be severe. 

On the other hand, myocarditis associated with the mRNA vaccine tends to be more mild. Vaccine-associated myocarditis is very rare and generally affects older adolescent males after the second dose. In that population, the incidence of myocarditis after the second dose is about 1 in 10,000 or 0.01%. 

The Pfizer-BioNTech COVID-19 vaccine trial for five to 11-year-olds included 4600 children, 3000 of whom received the vaccine. Of those 3000, none had myocarditis.

When the FDA and the CDC considered the risks for children in the younger age group, they reviewed the myocarditis incidence rate for the older children (the 0.01 percent) and plugged it in into a formula to really assess the risk and benefit for the younger age group. Even using this higher estimate for vaccine-associated myocarditis, the risk/benefit analysis concluded that the benefits of the vaccine outweigh the risk. – Dr. Rebecca Bell

What do you say to parents who prefer to wait and see?

Earlier in the pandemic some were hopeful that the SARS-CoV-2 virus would go away eventually. Unfortunately, that's not the case. The virus is here to stay. Our children will be exposed to this virus over and over again. We want their immune systems to be as prepared as possible. 

As of early November, 80 percent of Vermonters age 12 to 17 have received this Pfizer COVID-19 vaccine. That’s 31,000 Vermont adolescents, and they join around 13 million other U.S. adolescents who've received the Pfizer vaccine. More than 100 million people in the U.S. have received at least two doses of the Pfizer vaccine. We’ve been vaccinating people for more than a year which leaves us with a lot of data from adults and adolescents.

The COVID-19 vaccines are the most closely watched vaccines in the history of vaccines. – Dr. Rebecca Bell

Does my child need the vaccine if they’ve already had COVID-19?

It’s true you make antibodies to the virus when you are infected, but they are not necessarily guaranteed to be strong enough to prepare your body for a future infection. The antibodies from the vaccine are considered much more powerful and far better at protecting you from COVID-19 than what you get from experiencing an actual infection. The CDC, the FDA and pediatricians strongly recommend the vaccine even if your child has had COVID-19. – Dr. Lewis First

Should I worry about long-term side effects or future issues after vaccination?

We don't see late-onset side effects from vaccines. Even very rare side effects are apparent within two months of receiving a vaccine. We never see anything show up five or 10 years later. Unfortunately there's always lots of misinformation about really scary stuff that people hear on the internet around things like fertility and development issues, but there is no biologic mechanism by which that would happen. – Dr. Rebecca Bell

How long will vaccines protect a child?

Just like with the adult vaccine and other children’s vaccines, we need to monitor the level of antibodies that people have after they have been vaccinated and if these start to diminish over months or years. It is possible a booster may be needed for children, just like adults. That being said, a child’s immune system is felt to be primed to produce strong antibodies even more so than an adult—so perhaps a booster may not be needed once a child gets this vaccine. We will need to wait and let the science tell us if a booster is needed. – Drs. Rebecca Bell and Lewis First

How effective is the first dose of the vaccine for children? 

The studies to date suggest children achieve 90.7 percent effectiveness of the vaccine from two doses (the second dose three weeks after the first). The one dose, though it offers protection, does not achieve 90 percent which is why children need two doses. – Drs. Rebecca Bell and Lewis First 

Are there new formulations of the vaccine after the trials for children age five to 11? Like the addition of Tromethamine?

The formulation of the Pfizer vaccine for children contains a lower dose of the mRNA needed to make the antibodies to the spike protein of the SARS-Cov-2 virus. Tromethamine, a chemical buffer to keep the mRNA from degrading too quickly, has been added to enable the vaccine to last longer in office refrigerators than the adult formulation. The amount of tromethamine is extremely small and is not considered to pose any adverse health effects to adults or children if used in a vaccine, just as it has not been found to do when this chemical is used as a preservative or stabilizer in cosmetics and fragrances. The pediatric formulation with the addition of tromethamine has been found safe by the FDA and poses no harm to children who receive the new lower-dose formulation of this vaccine. – Drs. Rebecca Bell and Lewis First

 Stay Informed

Sign up to receive the latest stories, information and guidance from our experts on a wide variety of health topics.