UK and Myocarditis: Evidence-based information

Recently there has been some worry from parents, children and adults. There is little to worry about for 12–17-year-olds taking the vaccine, as there was a pre-print study (not yet peer-reviewed) claiming that this specific age group had a higher likelihood of getting myocarditis in boys post-vaccination. The study is completely flawed. The pre-print draws data from VAERS (I’ve talked about in another article), which by itself cannot be used to infer causality with the vaccine for myocarditis. The rest of the article explains in-depth about myocarditis and the UK data surrounding this to allay any fears that maybe present.

➡️ What is myocarditis? According to Healthline — “Myocarditis is a disease marked by the inflammation of the heart muscle known as the myocardium — the muscular layer of the heart wall.” (Source:

➡️ When we look at myocarditis from people that had Covid-19, it was 16x higher than those who were not infected with SARS-CoV-2. (Source:

➡️ Research from AHA Journals found that myocarditis as a very rare side effect is happening because the mRNA vaccine(s) triggers the immune system and temporarily inflames the heart. Hence why myocarditis is more common after the second dose compared to the first dose. Again a very low percentage of cases. (Source:
The positive is that people post-vaccination who had myocarditis, fully recovered. (Source:

➡️ Myocarditis MHRA Yellow Card Scheme Data.
(Data up to 1st September 2021)
Pfizer: 238 reports
AZ: 101 reports

Total doses of Pfizer administered: 40 million doses
Total doses of AZ (Oxford) administered: 48.9 million doses

Mathematical risk across all age groups of getting myocarditis (without incidence or prevalence rate):
Pfizer: 0.000005%
AZ: 0.000002%
Myocarditis risk for the Pfizer vaccine is 1 in every 168,067 doses.
Myocarditis risk for AZ (Oxford) vaccine is 1 in every 484,158 doses.

➡️ Incidence rate of myocarditis within the UK
“In one study from the UK, it was estimated that between 1998 and 2017 there were 36.5 per 100,000 NHS admissions with myocarditis, with the numbers increasing with each year since 2004. (Source:,with%20each%20year%20since%202004.)

➡️ Article from NewScientist also states that myocarditis is more common after Covid-19 infection than vaccination. (Source:

With the above information, the incidence rate of myocarditis with vaccination compared to the normal incidence rate of myocarditis is well below the UK average. Considering the safety factors, that all patients recovered after myocarditis (post-vaccination), the incidence rate is way lower than the average in the UK. This shows the vaccines are safe, the data proof is in the pudding.

💥 Thanks for reading, Lawrence. Please consider a small contribution, in the form of a beer as all articles are created in my small amount of spare time:



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Lawrence Robinson

Passionate about evidence-based scientific information and tackling falsehoods that thrive on social media.