(Updated 7 December 2021)

Background to myocarditis and pericarditis after COVID-19 vaccination and guidelines:

– this is a rare condition following vaccination (see the Medicines and Healthcare products Regulatory Agency’s (MHRA) weekly summary for the latest data)
– most patients who develop symptoms do so within a week of vaccination
– most patients who develop symptoms have usually been vaccinated with a mRNA vaccine (Pfizer or Moderna)
– myocarditis and pericarditis following vaccination is usually mild or stable and most patients typically recover fully without medical treatment
– myocarditis – a very small number of those with this condition have been admitted to hospital. In 2 studies from the US [footnote 1] [footnote 2], significant left ventricular (LV) fibrosis has been described in a high percentage of those children admitted to hospital, with a small percentage of these having non-sustained ventricular tachycardia (VT)
. no long-term follow-up data is available yet on hospitalised patients