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COVID vaccine side effects in kids with Dr. Jeff Perinca
Dr. Jeff Pernica, infectious disease physician at McMaster Children’s Hospital answers some common questions about the COVID-19 vaccine side effects in kids.
November 9, 2021

COVID vaccine side effects for children and youth

This story reflects the information available at the time of publishing. Please visit the City of Hamilton’s website for the latest information.

Many parents have questions about the side effects of the COVID-19 vaccine in children and youth. Dr. Jeff Pernica, infectious disease physician at McMaster Children’s Hospital answers some of those questions.


What are the COVID-19 vaccine side effects in youth?

What we know now in Ontario, is that adolescents in general have fewer side effects to the mRNA vaccines than any other age group so far. This is very reassuring. A lot of these side effects are mild and non-specific, such as headache, feeling tired and generally feeling unwell. These almost universally go away very quickly.

What is more common in teenagers, as compared to older people is heart inflammation, called myocarditis or pericarditis. This is rare, occurring somewhere between one in 5,000 to one in 10,000 teenagers who get the mRNA vaccine. For more information on this rare side effect, watch this video.

The vast majority of side effects in teenagers does not result in a need to see a physician or other healthcare worker, and does not result in hospitalization.

Are the vaccine side effects worse than a COVID infection for youth?

It’s very likely that a COVID vaccine will produce more benefit than harm in the vast majority of children and teenagers.

Severe disease from COVID is rare in pediatric age groups, but it does happen. As well, there are other post-infectious problems with COVID, such as multi-system inflammatory syndrome, which can be very severe and often require hospitalization. Also, the side effect profile of the COVID vaccines is quite good, with serious side effects only happening very rarely.

If there are side effects to the vaccine is it safe?

The safety process for the development and the evaluation of vaccines is more stringent, more protocolized than for just about any medication. Vaccines are about the safest intervention that current medical science has. With hundreds of millions of people across the world already immunized with the COVID vaccine, we have a very good idea that it’s safe. Again, getting a vaccine is probably the safer choice for the vast majority of our children.

If kids are less likely to get COVID and experience severe illness or hospitalization than adults, why should they get vaccinated?

Again, even though severe COVID-19 disease is rare in children and teenagers, it can happen. Many children and families are keen to get vaccinated because they feel it’s the safer choice, which is a great reason. Others aren’t necessarily worried about the child themselves getting sick, but rather fragile friends and family members, such as elderly or immunocompromised people living within the household or at school. This is also a very good reason for children and parents who are considering getting vaccinated. Finally, there are many kids who just want to go about their daily lives without missing school or other activities. For this reason they’re choosing to get the COVID-19 vaccine.

All of these reasons are a safe and responsible choice.

What advice do you have for parents who are still hesitant about the COVID vaccine for their kids?

Parents who are skeptical are just trying to do the best they can for their families and children. Seek out information from trusted reliable sources, like a family physician or a reputable website such as, which is put out by the Ontario COVID-19 vaccine table. Reliable information can also be found from local public health units. Finally, there is an information hotline in Ontario – the Provincial Vaccine Information Line 1-888-999-6488 – that parents or children can call with questions about the vaccine.

It’s always a great idea to get more information from reputable sources.