First Identified Case of Fatal Fulminant Necrotizing Eosinophilic Myocarditis Following the Initial Dose of the Pfizer-BioNTech mRNA COVID-19 Vaccine (BNT162b2, Comirnaty): an Extremely Rare Idiosyncratic Hypersensitivity Reaction

J Clin Immunol. 2022 Apr;42(3):441-447. doi: 10.1007/s10875-021-01187-0. Epub 2022 Jan 3.


Rationale: Transient myopericarditis has been recognised as an uncommon and usually mild adverse event predominantly linked to mRNA-based COVID-19 vaccines. These have mostly occurred in young males after the second dose of mRNA COVID-19 vaccines.

Objectives: Fulminant necrotising eosinophilic myocarditis triggered by a variety of drugs or vaccines is an extremely rare hypersensitivity reaction carrying a substantial mortality risk. Early recognition of this medical emergency may facilitate urgent hospital admission for investigation and treatment. Timely intervention can lead to complete cardiac recovery, but the non-specific clinical features and rarity make early diagnosis challenging.

Findings: The clinical and pathological observations from a case of fatal fulminant necrotising myocarditis in a 57-year-old woman, following the first dose of the Pfizer-BioNTech vaccine, are described. Other causes have been discounted with reasonable certainty.

Conclusion: These extremely rare vaccine-related adverse events are much less common than the risk of myocarditis and other lethal complications from COVID-19 infection. The benefits of vaccination far exceed the risks of COVID-19 infection.

Keywords: COVID-19; adverse events; autopsy; death; eosinophil; hypersensitivity; myocarditis; vaccine.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • BNT162 Vaccine
  • COVID-19 Vaccines / adverse effects
  • COVID-19* / diagnosis
  • Female
  • Humans
  • Hypersensitivity* / complications
  • Leukocyte Disorders*
  • Male
  • Middle Aged
  • Myocarditis* / diagnosis
  • Myocarditis* / etiology
  • RNA, Messenger
  • Vaccines*


  • COVID-19 Vaccines
  • RNA, Messenger
  • Vaccines
  • BNT162 Vaccine