Covid-19: Should we be worried about reports of myocarditis and pericarditis after mRNA vaccines?
You may have heard news about a small number of adolescents and young adults who experienced mild cases of heart inflammation (myocarditis or pericarditis) after getting the Covid-19 vaccine.
Symptoms of myocarditis or pericarditis can vary but often include shortness of breath, a forceful heartbeat that may be irregular, and chest pain. Heart inflammation is a complication seen with a range of viral infections, including Covid-19 itself. Average incidence of myocarditis ranges from 1 to 10 in 100 000 people a year.
As of June 11 this year, the U.S. Centres for Disease Control and Prevention has recorded 323 confirmed cases of myocarditis and pericarditis, among people aged 12 to 29, mostly documented within a week after each patient had received one of the mRNA Covid-19 vaccines made by Pfizer-BioNTech and Moderna.
So far, post-vaccination myocarditis has been most commonly reported among people in their late teens and early 20s, according to the Centre’s report. The condition is more likely to occur after the second dose, and it happens more often in boys and young men than in girls and women.
Overall, rates of post-vaccination myocarditis and pericarditis are higher than rates normally seen from other causes, But cases are still infrequent, and the vast majority of patients have responded quickly to treatment.
In the UK from the 16th of June 2021 the Medicines and Healthcare Products Regulatory Agency (MHRA) had received 53 reports of myocarditis and 33 reports of pericarditis (including one death) after use of the Pfizer-BioNTech vaccine.
The fact that these numbers are particularly increased in younger (male) adults, and high numbers of the population have now received a covid vaccination, it makes it more difficult to determine whether the relationship to vaccination was the cause or coincidence i.e. some events may have happened anyway, regardless of vaccination. This is particularly the case when millions of people are vaccinated.
According to the experts, more rigorous studies using alternative data sources and more robust study designs are underway, and they will continue to review the situation as more data becomes available.
So what does this mean to young people awaiting the vaccine?
According to Kamlesh Khunti, Professor of Primary Care Diabetes and Vascular Medicine at the University of Leicester and a member of the government’s Scientific and Advisory Group,
“Vaccination always serves two purposes, firstly to benefit the person who gets it and secondly to benefit others. We are willing to do things for the second purpose but not if they are a going to harm the individuals.”
Overall, the number of reports of myocarditis and pericarditis reported with the vaccines in the UK remains similar or below the amounts found in different age groups within the general population and does not currently indicate an increased risk following vaccination against Covid-19.
We will continue to closely monitor these events reported in the UK and internationally.