Heart inflammation risk post Covid-19 vax rare : Lancet

Singapore : The overall risk of myopericarditis – a type of heart inflammation – following a Covid-19 vaccination is rare and is comparable to or lower than the risk following non-Covid shots, confirms a study published in The Lancet Respiratory Medicine. Researchers from National University Hospital, Singapore examined international databases, looking at more than 400 million vaccination doses, to compare the risk of myopericarditis following vaccination against Covid-19 and other diseases such as influenza and smallpox. They found no statistically significant difference between the incidence of myopericarditis following Covid-19 vaccination. The rate of myopericarditis following Covid jab was 18 cases per million doses. For all other viral vaccinations combined, the rate of myopericarditis was 56 cases per million doses.

 

“Our research suggests that the overall risk of myopericarditis appears to be no different for this newly approved group of vaccines against Covid- 19, compared to vaccines against other diseases,” said Dr. Kollengode Ramanathan, a cardiac intensivist at the Hospital. “The risk of such rare events should be balanced against the risk of myopericarditis from infection and these findings should bolster public confidence in the safety of Covid-19 vaccinations,” Ramanathan added. Among Covid vaccinations, the risk of myopericarditis was higher for those who received mRNA vaccines (22.6 cases per million doses) compared to non-mRNA vaccines (7.9 cases per million doses); and those below the age of 30, males, and also following the second dose of a Covid shot. Myopericarditis is a condition that causes inflammation of the heart muscle and, in some cases, severe permanent heart damage. It is most often caused by viruses but can also occur after vaccination in rare instances. There have been reports of myopericarditis following mRNA-based Covid-19 vaccination, especially in adolescents and young adults.

 

To explore, the team analysed more than 20 studies from international databases with reported incidences of myopericarditis following any type of vaccination between January 1947 and December 2021. Of these, 11 studies looked specifically at Covid vaccinations, covering over 395 million Covid-19 vaccine doses – nearly 300 million of which were mRNA vaccines. The rest of the studies covered other vaccinations such as smallpox (2.9 million doses), influenza (1.5 million doses), and others (5.5 million doses). “The occurrence of myopericarditis following non-Covid-19 vaccination could suggest that myopericarditis is a side effect of the inflammatory processes induced by any vaccination and is not unique to the SARS-CoV-2 spike proteins in Covid-19 vaccines or infection,” said Dr Jyoti Somani, an infectious diseases specialist at the Hospital. “This also highlights that the risks of such infrequent adverse events should be offset by the benefits of vaccination, which include a lower risk of infection, hospitalisation, severe disease, and death from Covid-19,” she added.