What is the risk of getting myocarditis or pericarditis after the vaccine?
The risk of getting myocarditis or pericarditis after the vaccine is very low.
According to the MHRA Yellow Card report summary, published on 1 December 2022, even in the highest-risk age group (18-29), there were just 29 reports of suspected myocarditis or pericarditis for every million second doses of the monovalent Pfizer vaccine given in the UK up until 23 November 2022. The risk is even lower following a monovalent Pfizer booster, with just 17 reports per million people in this age group. In other age groups the risk is even lower.
For the monovalent Moderna vaccine, there were 70 cases of suspected myocarditis or pericarditis for every million second doses given in the UK, in this age group. As with the monovalent Pfizer vaccine, the risk is much lower after a booster, with just 20 reports per million monovalent Moderna boosters given (up until 23 November 2022). In other age groups the risk is even lower.
So far, the bivalent vaccine is following a similar pattern. The Yellow Card report summaryfrom 13 January 2023 reported that for the bivalent Pfizer vaccine, there were just 14 cases of myocarditis and pericarditis per million doses in the 30-39 age group (up until 28 December 2022). Currently, there isn’t enough data to estimate the risk to younger age groups or for the bivalent Moderna vaccine.
The World Health Organisation has reviewed data from 744,235 doses of the Novavax vaccine given in Australia, Canada, the European Union, New Zealand, and South Korea up until 30 April 2022. Amongst these recipients, there were four reports of myocarditis, 29 reports of pericarditis, and two reports of myopericarditis. More recent data from Australia (until 21 August 2022) showed seven cases of myocarditis and 26 cases of probable pericarditis after 209,000 doses of the Novavax Covid vaccine.
Serious illness with myocarditis after the vaccine has so far been exceptionally rare, although more research is being carried out into the long-term effects of post-vaccine myocarditis on heart health.