A: Rare cases of myocarditis have been reported after mRNA vaccines, particularly in young men. Reported cases have been mild and treatable.
👉🏽TL;DR: Cases of myocarditis have been reported following COVID-19 mRNA vaccines, particularly in younger men. All of these people recovered quickly after treatment. A definitive link between COVID-19 mRNA vaccines and myocarditis is not yet clear. However, the benefits of vaccination in preventing COVID-19 far outweigh the risk, and the cases of myocarditis that were reported were mild and easily treatable.
➡️What is myocarditis?
Myocarditis is inflammation of the heart muscle. Inflamed heart muscle (like any other muscle) cannot work properly and cannot pump blood effectively to reach all parts of the body. People with mild cases of myocarditis may not have any symptoms, or might have chest pain or shortness of breath. People with severe myocarditis can have extreme fatigue, swelling of the feet, ankles or leg, chest pain and difficulty breathing.
Viral infections (including COVID-19), are a common cause of myocarditis. Some autoimmune diseases, certain medicines and exposure to radiation can also cause myocarditis. Mild myocarditis can be treated with anti-inflammatory medicines, rest and fluids, while more severe cases require hospitalization and specific treatment of the underlying cause.
➡️COVID-19 vaccination and myocarditis – what we know :
1. Researchers in Israel reported cases of young men (16-24 years) who developed chest pain and breathing difficulty after the second dose of the Pfizer vaccine. The estimated rate of these symptoms was 1 out of 3000-6000 young men vaccinated. They were diagnosed with mild myocarditis (inflammation of the heart). They were treated promptly with anti-inflammatory medicines and recovered.
2. In the US, the Federal Drug Administration (FDA) just released a new analysis of VAERS (Vaccine Adverse Events Reporting System) and VSD (Vaccine Safety Data Link) data. 226 reports of myocarditis in those under age 30 met the CDC case definition, which is above expected rates for ages 16-24 but not for other age groups. Estimates from this early data are an incidence rate of 8.6 cases per million doses administered in those 16-39, with the risk higher for second doses compared to first doses and higher in males.
➡️Why might myocarditis occur after COVID-19 vaccination?
Myocarditis after COVID-19 vaccination (specifically with the mRNA COVID-19 vaccines) is a very rare phenomenon. Researchers are continuing to study whether there is a definite link between these COVID-19 vaccines and myocarditis. Thus far, myocarditis has occurred mainly in teenage boys and young men under the age of 30 years. One of the possible explanations is that because these vaccines induce very high levels of antibodies and are strong stimulators of the immune system, they might lead to an exaggerated immune response that could cause inflammation of the heart. However, further research needs to be done to understand if this is indeed the case. Perhaps increasing the time between the first and second dose might decrease this immune overreaction, although this has not been proven as yet. Several countries are increasing the interval between the first and second dose to 12 or up to 16 weeks. Whether myocarditis cases decrease with this vaccination strategy remains to be seen. The current recommendation in the US is a 3-week gap between the first and second vaccine dose for Pfizer and 4 weeks for Moderna.
😟I’m worried! Should my teen receive the COVID-19 vaccine?
While both the Israeli and FDA reports found rates in young men that were higher than what would normally be expected, the analysis is still on-going and the link is not 100% definitive.
The good news is that even if the link proves causal, the risk of getting myocarditis after COVID-19 vaccination is VERY SMALL, and the course is mild and is treatable. Most people recovered after treatment with anti-inflammatory medicines and/or steroids.
COVID-19 itself is a serious risk for myocarditis and many other complications. Given that COVID-19 cases are increasing among young people, getting vaccinated is EXTREMELY important. In spite of the small number of cases of myocarditis that have been reported, the American Academy of Pediatrics and the CDC strongly recommend that teens get vaccinated.
❗What symptoms should I watch for?
Watch for chest pain or difficulty breathing – if these symptoms occur, do consult your doctor. The CDC also encourages reporting of these (or any symptoms) to their Vaccine Adverse Event Reporting System (VAERS): https://www.cdc.gov/…/2019-ncov/vaccines/safety/vaers.html
This allows the CDC to track, investigate and understand any unusual symptoms after vaccination and work with doctors and scientists to provide advice on managing these symptoms.
Common symptoms after vaccination include arm pain where you received the vaccine, fever, chills, feeling tired, muscle aches and swelling of the lymph nodes in your armpit. All of these are normal reactions to the vaccine and indicate that your immune system is getting revved up.
💥BOTTOM LINE: To date, millions of people including thousands of teens have received the COVID-19 mRNA vaccines. The vaccines are SAFE, however, a few young men and teenage boys have developed mild and easily treatable myocarditis which may be related to the vaccine.
The benefits of vaccination in preventing COVID-19 FAR OUTWEIGHS the risk of this side effect.
Stay safe!
Love,
Those Nerdy Girls
Further reading.
Reports of myocarditis following COVID-19 vaccination in Israel (Science Magazine)
FDA report on myocarditis in the US
American Academy of Pediatrics recommendations for COVID-19 vaccination
CDC guidance on vaccination and reports of myocarditis
Statement from the American Heart Association
