evidence: There have been rare cases of serious adverse events reported with the COVID-19 vaccines. Previous studies have shown an increase in the risk of myocarditis and myopericarditis associated with mRNA vaccines including BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)8,11, and an increased risk of thrombotic and other rare cardiovascular events after the ChAdOx1 nCoV-19 vaccine (Oxford-AstraZeneca)12,13. There is also evidence of a range of other rare neurological complications14. However, the absolute risk of severe complications is low and needs to be assessed against the increased risks associated with SARS-CoV-2 infection if unvaccinated15,16. The balance of risk and benefit is particularly important to determine in younger people, due to the lower risk of COVID-19 hospitalisation and death in this age group17. [...] Whilst COVID-19 vaccination has been linked to an increased risk of myocarditis and other cardiac events in young people, we found no evidence of substantially increased mortality risk, either due to cardiac events or overall, from mRNA vaccines, which suggest that cases of myocarditis or myopericarditis due to mRNA COVID-19 vaccines are unlikely to be fatal. We do, however, find evidence of an increased risk of cardiac death after a first dose of a non mRNA vaccine among females. It should also be noted that non mRNA vaccines are no longer used in the UK vaccination programme28. This provides reassurance that mRNA vaccines pose minimal risk of increased mortality in the first twelve weeks post-vaccination in young individuals. However, it is important to continue to monitor mortality after vaccination as more deaths are being registered, and extend the surveillance to other age groups and deaths from other causes.