Heart Inflammation after COVID-19 Vaccine


The vaccine developed to treat COVID-19 has been a topic of hot debate since its inception. With questions swirling regarding the speed at which it was developed, its long-term efficacy, potential side effects that may not yet have come to light, and mandates instituted by businesses and governments across the globe, everyone is craving one thing—actual data to dispel or legitimize concern.

One cause for concern has come from the emergence of an unforeseen side effect. Myocarditis, inflammation of the heart muscle, has been linked to the COVID-19 vaccine, adding fuel to the fire of debate. Without long-term research, however, the commonality and severity of this side effect remain unknown.

Different Types of COVID-19 Vaccines



The Data

A recent study  shed light on this topic by evaluating exactly those issues. How common is myocarditis in COVID-19 vaccine recipients, and how severe are the cases that do occur?

Included in the data set used for this study were patients who had received a minimum of one dose of the Pfizer-BioNTech mRNA vaccine. At the time of this research, this included 2.5 million vaccinated individuals aged 16 or older.

Anyone who fit this demographic and developed myocarditis up to 42 after their first dose was counted as being affected by this side effect. At the time, this was found to be 2.13 people per 100,000. However, this incidence rate varied based on a number of factors. For example, males aged 16 to 29 years old experienced the highest rate of myocarditis, with 10.69 cases per 100,000 vaccinated persons.

The majority of cases (98%) of myocarditis were overwhelmingly mild. 76% of cases fell into this classification, while 22% were considered intermediate.

What it Means

This study is a start, but it is too soon to determine how the data will change as time progresses. Because the research only included patients up to 42 days removed from their first dose of vaccine, it is possible that myocarditis developed in more patients after the 42-day window closed. The research performed does provide actual numbers to inform the concerns regarding vaccination and myocarditis. Majority of the myocarditis cases were mild and no risk of death.

According to CDC, most individuals can safely receive the vaccine and enjoy the benefits of protection and peace of mind.

You can consult with one of our experienced cardiologists through a virtual visit or in person at one of our clinic locations. To schedule an appointment, call Peak Heart & Vascular in Surprise, Avondale, Flagstaff, or Phoenix, Arizona, or connect online to submit an appointment request for an in-office or virtual visit.


  1. https://nejm.org/doi/full/10.1056/NEJMoa2110737
  2. https://cdc.gov/coronavirus/2019-ncov/vaccines/recommendations/children-teens.html

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