Patient 1 was a 28-year-old Caucasian woman who presented with a 4-day history of chest pain to the same day emergency care unit at the Western General Hospital, Edinburgh, Scotland. The patient had received a second dose of the mRNA-1273 (Moderna) vaccine for COVID-19 five days previously. After vaccination, she felt unwell with fever and dry cough. Shortly after, she developed chest pain. The patient had no background medical history and her clinical examination was unremarkable. Patient 2 was a 29-year-old Caucasian man who presented with chest pain to the Sahlgrenska University Hospital, Gothenburg, Sweden. The patient had received a second dose of the mRNA-1273 (Moderna) vaccine 3 weeks prior to admission. He described a similar episode of chest discomfort a few days after vaccination. The patient had a history of asthma but was not receiving regular medication. His clinical examination was normal. Patient 3 was a 19-year-old Caucasian man who had COVID-19 confirmed using a reverse transcription-PCR test. He experienced mild breathlessness and headache and was generally unwell. Six weeks following confirmed COVID-19 infection, he developed chest pain, which prompted admission to the Sahlgrenska University Hospital, Gothenburg, Sweden. The patient had a history of asthma. The clinical examination was normal.