A Canadian study shows that myocarditis and pericarditis after COVID-19 mRNA vaccinations are extremely rare.
This research also suggests that spacing out second doses to 30 days and offering Pfizer vaccines over Moderna might lower the risk of developing these conditions in men ages 12-29.
Experts stress that developing COVID-19 poses a greater risk of myocarditis and pericarditis than being vaccinated.
Experts at the University of Alberta in Canada have analyzed evidence on the risk of myocarditis and pericarditis after COVID-19 vaccination and found the risk is low, including among young men. These conditions, typically caused by viral infections, involve inflammation of heart tissues.
The findings do confirm that the issues occur more frequently among young males shortly after a second dose of the mRNA vaccine.
Most cases have been mild, and the risk appears to be higher after receiving Moderna’s mRNA vaccine than Pfizer’s counterpart.
The researchers propose that using Pfizer over Moderna and spreading out dosing intervals might reduce risks for younger individuals.
Myocarditis refers to the inflammation of the heart muscle, and pericarditis occurs when there is inflammation of the sac surrounding the heart. Both conditions are typically caused by a viral infection.
The conditions are rare but serious. Fortunately, most people fully recover.
An uptick in cases after COVID-19 mRNA vaccinations has generated concern among medical and public health leaders.
Reports first appeared in April 2021, leading to monitoring side effects after vaccination with Pfizer and Moderna’s mRNA vaccines.
Pediatric and heart specialists at the University of Alberta analyzed over 8,000 cases after combing through 46 studies.
They started investigating records of people in every age group and zoned in on individuals 0-39 years of age. According to the researchers, incident rates in adults ages 40 years and older were “very low to none.”
How frequent are they?
The researchers noted that the overall rates of myocarditis are 1-2 cases per 100,000 person-years in the United States. Person-years is a measurement used in prospective studies where researchers consider the number of participants involved and how much time each person spends in the study. If a study followed 100 people for 20 years, the research would contain 2,000 person-years of data.
