A number of recent studies have suggested that healthcare professionals should be aware of hypersensitivity myocarditis, which can occur as an uncommon adverse reaction to COVID-19 vaccinations. Researchers stress that this awareness does not mean that vaccination confidence should be diminished during this current pandemic.
They suggest that although there are more cases of myocarditis after vaccinations than at baseline, there is still a greater chance of developing heart disease and death from COVID-19 infection. The researchers note that up to 60% of those who become seriously ill from COVID-19 have suffered injury to their hearts. Nearly 1% of athletes who have had mild COVID-19 infections show myocarditis in an MRI.
JAMA Cardiologystudied 23 soldiers who developed myocarditis symptoms after receiving the second dose. Three patients had previously been infected by COVID-19 and symptoms began after receiving the second dose.
All 23 military patients experienced severe chest pain and elevated levels of cardiac troponin. The rapid recovery of each patient, together with the timing of the symptoms, support the diagnosis hypersensitivity myocarditis.
"Hypersensitivity myocarditis after vaccination is uncommon, with the exception being smallpox vaccine." Leslie Cooper, chief of the Department of Cardiology at Mayo Clinic Cooper was the senior author of the study. It was done with US military medical centers.
A second observational study included details of eight men aged between 21 and 56 who were admitted to hospital with chest pain. They were diagnosed with myocarditis using laboratory and cardiac magnetic resonance imaging. Within two to four days after receiving their second COVID-19 vaccination, the patients experienced symptoms that included a fever and other signs. One patient, who had been treated with COVID-19 before, developed symptoms shortly after receiving the second dose. The effects of myocarditis were reversed in all eight patients. They also experienced no chest pain. Cooper and researchers from Mayo Clinic, the USA, and other medical institutions in Italy co-authored the findings. They are published in Circulation.
People of all ages should get the COVID-19 vaccine, as the risks and benefits are very low. Cooper says that almost all cases of vaccine-associated myocarditis are resolved quickly by the increasing body of research.