Examining Pediatric Myocarditis Risk with COVID-19 Vaccination with Matthew E. Oster, MD, MPH

In late January, a team of investigators from the Centers for Disease Control and Prevention (CDC) reported findings from the Vaccine Adverse Event Reporting System (VAERS) indicating a significantly low risk of myocarditis following vaccination with either available messenger RNA (mRNA) vaccine for COVID-19 in persons aged 24 years and younger.

Cases of the inflammatory heart event occurred 1626 times after an mRNA vaccine dose in US patients from December 2020 to August 2021.

Though the prevalence of myocarditis was deemed significantly low (.0000046% of the 353,100,845 total doses of the mRNA vaccines administered at that time), Matthew E. Oster, MD, MPH, of the CDC and the Emory University School of Medicine spoke with HCPLive of the importance of monitoring these events as well as how they fare against what is seen among patients who are not vaccinated against the virus.

“Anytime when vaccines are rolled out, we have an obligation to understand not only benefits but also risks to put everything into a good benefit-risk assessment,” Oster said. “As we started seeing reports and hearing about cases of myocarditis, we really wanted to get a grasp on: how severe is this? How common is it, who's being affected, and what is their clinical picture looking like? So it's kind of going a little bit beyond what we typically do.”

Current data shows that this event has primarily affected young male patients from 12-29 years old. Fortunately, Oster noted that there has been much less of a need for critical care among patients affected, and no deaths were recorded in the cases the CDC has been able to fully investigate.

By most accounts, these cases of myocarditis are milder with a quick resolution of symptoms and minimal treatment required. In each reported case, Oster noted that the CDC are keeping in contact with those affected, as well as their providers and available cardiologists.

“I know it's scary when we're talking about kids and having myocarditis from having a vaccine, but it's still not nearly as common as having heart involvement and COVID-19,” Oster said. “When you have COVID-19, a number of things can happen related to the heart.”

Acute and severe heart infections among patients infected with COVID-19 have been reported. Oster referenced one particular case in which a young, unvaccinated patient was sent to the cardiac intensive care unit due to infection (what Oster referred to as an “avoidable outcome”).

Additionally, heart inflammation has been significantly linked to COVID-19 infections, as has multisystem inflammatory syndrome in children. Though the latter affects about 1 in every 3000 children who are infected by the virus, about 80% of those cases will result in some sort of cardiac involvement.

Though myocarditis has been reported in some of the national meetings, Oster reiterated that the rates of myocarditis in younger children appears to be much lower than what was seen in older children/young adults, adding that the benefits of vaccine outweigh the risks of COVID-19 infection.

“There's a lot that can affect the heart as a result of COVID-19, and because of that we think the benefits of getting vaccinated and avoiding those bad outcomes still outweighs the risk of myocarditis,” Oster said. “It’s real, it is there, and something we need to monitor and watch. But it is still much lower than the risk of getting cardiac effects from COVID-19.”