While many parents may be eager to protect their kids from COVID-19, they may be concerned about reports that some young people have experienced heart inflammation after getting the COVID vaccine.

And families whose children already have an underlying congenital heart condition may especially be trying to weigh such side effect risks against the risks of a COVID infection.

These are understandable concerns, said Jesse Hansen, M.D., pediatric cardiologist at University of Michigan Health C.S. Mott Children's Hospital who also sees patients in the pediatric post-COVID syndrome clinic.

But there's reassuring news: This heart inflammation known as myocarditis and pericarditis after COVID vaccination is very rare. Most cases have also been mild and short-lived, with patients recovering after a few days.

In fact, heart inflammation occurs at much higher rates from a COVID infection itself, studies find.

Answers to 11 common questions about COVID vaccines and kids' hearts

1. What are myocarditis and pericarditis?

Hansen: Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the lining outside the heart. In both cases, the body's immune system causes inflammation in response to an infection or another trigger. While there are many possible causes for this type of inflammation, viral infections like influenza and COVID-19 are the most common cause.

Symptoms generally include persistent chest pain and shortness of breath. Other symptoms like racing heart, dizziness, or excessive fatigue may be present but are more frequently related to more common causes.

2. Can COVID vaccines affect the heart?  

Hansen: For most kids, the vaccine will have no effect on their heart. But health officials are monitoring very rare occurrences of myocarditis and pericarditis after vaccination.

The risk is low, seen in less than 1 in 20,000 vaccinated children ages 12-17 (and even less frequently in other groups) with symptoms usually appearing within one to four days after the second dose.

It's important to note that while also rare, a COVID-19 infection is more likely to trigger heart inflammation than a vaccine.

3. How serious are myocarditis and pericarditis?

Hansen: Most adolescents and teens with vaccine associated myocarditis have mild symptoms like chest pain and shortness of breath that get better after a few days. They're often treated with anti-inflammatory medicine like ibuprofen and may be hospitalized for observation, generally less than three days.

Myocarditis can be serious and even life-threatening. Children who have it should always be followed by a cardiologist to make sure the heart remains healthy as the inflammation goes away.

The Congenital Heart Center at Mott has been part of a large network of pediatric hospitals that have been monitoring the situation very closely. While we're continuing to learn about this reaction, we're seeing heart function return to normal and don't expect long-term consequences to be common. 

4. Are young people and teens at a higher risk of this complication?

Hansen: This rare event can happen in any age or gender, but most cases have been in boys and young men ages 12 to 29. Even in the highest risk group of boys ages 12-17, myocarditis is only seen in 1 out of every 15,000 vaccinated individuals.    

The Pfizer vaccine is authorized for use in patients as young as 12 years old while Moderna is currently only available to patients 18 and older.

5. What do we know about the link between myocarditis and the vaccine?  

Hansen: Many of the medical problems caused by COVID have been related to the immune system's response to infection. Vaccines are designed to turn on the immune system and train it to recognize the virus or bacteria scientists are trying to prevent in a safer way than the immune system responds to natural infection. Myocarditis related to the mRNA COVID vaccines is a result of the immune system response causing inflammation in and around the heart.

6. Are kids with congenital heart disease at higher risk of this side effect or worse outcomes if they experience it?

Hansen: Children and adults with congenital heart disease are not at higher risks of getting myocarditis because of their heart history. If they do get myocarditis (from any cause), they will need to be followed closely by their cardiologist.

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7. Are children with complex heart disease at higher risk of severe sickness from COVID? 

Hansen: Large studies of children and adults with congenital heart disease have found that congenital heart disease itself is not a strong risk factor for severe COVID infection. However, some patients with congenital heart diseases have other conditions like problems with their lungs, blood vessels, kidneys, and immune system that can increase the risk of severe illness. Vaccination is particularly important for this group of patients.

8. Are there any kids with heart conditions who shouldn't get the COVID vaccine?

Hansen: Heart conditions are not generally a reason to avoid vaccination. In fact, we strongly recommend vaccination to all our eligible patients so they can be protected from the higher risks that come with a COVID infection.

There are small groups of patients who have recently had heart surgery or are on special medications that affect the immune system—these patients should speak with their cardiologists to decide what's right for them.

While children have generally done very well with COVID infection so far, the only way to prevent the rise of new COVID variants is through vaccination. With the delta variant, pediatric hospitalizations have been on the rise and severe COVID infection is more common in children compared to prior variants. Other risks to children from COVID infection include a serious disease called multi-system inflammatory syndrome (MIS-C) and lingering symptoms of fatigue, brain fog, and shortness of breath ("long haul COVID") that can significantly impact quality of life even in patients with mild COVID infections. While the risk of vaccine-associated side effects is real, the risk to children from COVID infection far outweighs the risks of the vaccine.

9. How do you know if your child has myocarditis?

Hansen: If your child experiences chest pain, shortness of breath or feelings of having a fast-beating heart after a COVID infection or within four to five days after the COVID vaccine, they should be seen by a doctor. Several tests can be used to test for myocarditis including ultrasounds of the heart (echocardiogram), electrical measurements of the heart (electrocardiogram), and an MRI of the heart. Not all patients suspected of having myocarditis will need all these tests.

10. How long after myocarditis should kids wait to return to playing sports? 

Hansen: Youth athletes should be evaluated by a cardiologist and receive cardiac clearance before returning to sports or other physical extracurricular activities. This usually happens about three to six months after the diagnosis of myocarditis. Once cleared, children should go through a return to play protocol where they gradually increase their activity and track any potential symptoms.   

If they experience any chest pain, shortness of breath, fatigue or palpitations, they should contact their doctor.

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11. If a child has a complex congenital heart condition and is too young to get vaccinated, should families consider keeping them home from school or other activities where they may be around unvaccinated people during the delta surge?

Hansen: This decision is very hard and should be made in coordination with doctors who know the children, families, and communities well. While protecting children from infection is important, keeping kids out of school also affects their social, emotional, and academic development, which are very important in long term health outcomes. This is why the Centers for Disease Control and Prevention and the American Academy of Pediatrics have recommended in-person learning with vaccination for those who are eligible and universal masking mandates in schools. Parents should consult with their child's provider as they make these decisions.