COVID-19 update: Myocarditis and COVID-19 vaccine
Many of you are asking about a possible association between heart inflammation (myocarditis) and COVID-19 vaccine, so this update primarily addresses this concern.
Here is the short story: The Advisory Committee on Immunization Practices (ACIP) met last week to review the data on this rare adverse reaction occurring shortly after receiving mRNA COVID-19 vaccination in young adults, particularly young men ages 16-24. They reviewed the 323 cases of myocarditis (temporary heart muscle inflammation) in about 8 million young adults vaccinated identified by the Vaccine Safety Database and determined that there is an association, but 95 % of the cases were mild and resolved quickly. There were no deaths. After comparing the risk of vaccine to the risk of COVID-19 disease, including over 4000 cases of COVID-19 disease MISC (Multisystem Inflammatory Syndrome in Children that causes severe heart inflammation), COVID-19 disease-related myocarditis, 17,000 hospitalizations in children due to COVID-19 disease, and over 300 deaths Source: AAP, ACIP advised that children ages 12 and up should continue to be vaccinated but providers should be vigilant in monitoring for this adverse event. Fourteen major medical organizations, including the American Academy of Pediatrics quickly followed with a letter of support to vaccinate teens and young adults with the COVID-19 vaccine.
Okay, here is the detailed version:
What is myocarditis?
Myocarditis is inflammation of the heart muscle. Myocarditis has many known causes including infection (viruses, parasites/protozoa, bacteria, fungi), certain medications, toxins, and immunologic syndromes. The COVID-19 virus has caused myocarditis as a complication of infection since the pandemic began. It appears the COVID-19 vaccine, in rare cases, can also lead to myocarditis but the mechanism of how that occurs is unclear.
What are the symptoms of myocarditis? Is it serious?
The good news is that most cases are very mild. In most cases, people develop symptoms 2-4 days after vaccination (usually the 2nd dose) and experience moderately severe chest pain or palpitations or shortness of breath. It seems to occur more in males, primarily ages 16-24 years old. Confirmed cases have changes on an EKG, an elevation of a blood test called a troponin, and an abnormality on a heart MRI indicating inflammation of the heart muscle. The vast majority of patients (95%) have mild cases, with symptoms improving within 48 hours and treatment with ibuprofen. There have been no deaths reported.
What are the statistics on risk of vaccine-related myocarditis?
The rate of myocarditis after vaccination is 13 in 1 million.
>In young women, the rate is 4 in 1 million.
>In young men, the rate is 32 per 1 million.
The greatest risk appears to be in young men between 16-24 years of age, more likely after the 2nd dose. There have been 323 cases reported to the CDC. 309 of those patients were hospitalized primarily for observation purposes and 295 were discharged home. Nine patients remain hospitalized at the time of reporting on June 11, 2021. There have been no deaths.
My child has a congenital heart defect, is it still safe to give the vaccine?
Yes. There is no association between underlying heart conditions or any other health issues and developing this complication.
If my child is diagnosed with myocarditis, will there be any exercise restrictions?
If someone is diagnosed with myocarditis (for any reason) with EKG changes, the current recommendation is that they cannot return to sports for 3-6 months. They can resume other activities of daily living.
If COVID-19 infection is rare in children, why should I give my child this vaccine?
You should get your child vaccinated because you are protecting them from a potentially very serious infection. While it is true that COVID-19 infection has been less devastating to children than adults, children DO get COVID-19 infection and some get very ill and die from this infection. There have been over 4 million cases of COVID-19 infection in American children and 25% of all new cases in the United States are in children. There have been over 17,000 pediatric hospitalization and over 300 deaths due to COVID-19 since the pandemic began.
Do you still recommend giving the vaccine to teenagers?
Yes. The death rate from COVID-19 in children is 2-3 times higher than for seasonal flu virus. And, the risk of developing myocarditis or MISC from COVID-19 infection is higher than the risk of developing this rare adverse reaction to the vaccine.
Should we worry about the Delta variant and others?
The best way to protect against this variant is to get vaccinated. We anticipate the Delta variant will be the predominant strain circulating in the US soon and the currently available vaccines offer great protection against it. Since COVID-19 is a winter virus, there will be an uptick in the fall and winter with the number of cases. The huge decline in cases right now is thanks to vaccination but also the seasonality of the virus.