COVID Vaccines and Cardiac Effects – Reality vs Lies


Science-Based Medicine

Steven Novella on January 5, 2022

COVID mRNA vaccines only result in rare, mild, and transitory myocarditis, but this doesn’t stop misinformation from spreading.

After airing a viral video showing a young athlete unconscious on the field following a cardiac arrest, anti-vaccine crank Del Bigtree asked his viewers, “All of these sports are mandating this vaccine on everybody in order to play, and I can only ask the very simple question, do you ever remember hearing a story of an athlete having a heart attack on the field?” The obvious implication is that this is a new phenomenon, and he is encouraging his audience to make a connection to the COVID vaccines. He also states there is no evidence for a connection, and he can also hide behind the notion that he is “just asking questions”, but the implication is undeniable, and that’s all it takes.

Social media also facilitates compiling and spreading video and audio clips to create what are in essence mini-documentaries, with a specific message apparently supported by the video evidence being presented. These videos, however, may be complete fabrications, all lies and misinformation. That athlete lying on the field, for example, had a cardiac arrest due to a primary cardiac condition having nothing to do with COVID vaccines. We can be highly confident that the vaccine was not involved – because the video is from 2013.

This is now the reality we are living in. Pictures can be used out-of-context to falsely support a narrative. Eventually, they tend to get debunked as “the internet” will generally find the source material and expose the fraud, but by the time this happens the damage is already done. This phenomenon is also not limited to social media – even major news outlets (like Fox News and Newsmax) have been caught red-handed using misleading photos out-of-context. This is combined with opinions presented as facts, or hiding behind posing leading questions without making explicit claims.

This misinformation not only affects people’s behavior, but can affect policy. Anti-vaccine crank Sheri Tenpenny, for example, was invited to give testimony to the Ohio Health Committee in support of a bill essentially banning vaccine mandates. Among the claims she made to the committee was that COVID vaccines “magnetize” people, and offered as evidence misleading videos from the internet.

The science about COVID vaccines and cardiac effects

Meanwhile the reality, slowly documented through careful scientific study, is that the current COVID vaccines are both safe and effective, and the reported cardiac effects are rare, mild, and transient. No one would reasonably argue that vaccines are entirely without side effects. No medical intervention is. They are designed to provoke a specific immune response, which creates the possibility of inflammatory side effects. One such side effect is myocarditis or pericarditis – inflammation of the heart or the lining around the heart, respectively.

According to the US Centers for Disease Control and Prevention, myocarditis/pericarditis rates are ≈12.6 cases per million doses of second-dose mRNA vaccine among individuals 12 to 39 years of age. In reported cases, patients with myocarditis invariably presented with chest pain, usually 2 to 3 days after a second dose of mRNA vaccination, and had elevated cardiac troponin levels. ECG was abnormal with ST elevations in most, and cardiac MRI was suggestive of myocarditis in all tested patients.

In almost every case the symptoms were mild and resolved completely, with or without treatment. This is a rare, mild, and transitory side effect, and therefore not a significant phenomenon, and not a reason to avoid the vaccine. Further, when considering any medical intervention we cannot only consider risk, we have to consider risk vs benefit. We know the vaccines are highly effective at preventing severe COVID, and based on that alone the benefits outweigh this tiny risk. However, the benefits are even more direct. COVID-19 itself is much more likely to cause myocarditis that the mRNA vaccines:

After adjusting for patient and hospital characteristics, patients with COVID-19 during March 2020–January 2021 had, on average, 15.7 times the risk for myocarditis compared with those without COVID-19.

This is not uncommon with inflammatory vaccine side effects, they often mimic (but are less severe and less common) complications of the very infection that they prevent. If a vaccine increases the risk of Guillain-Barré Syndrome (GBS – inflammation of the peripheral nerves) slightly, then it’s a good bet that the illness the vaccine prevents is far more likely to cause GBS itself.

In fact these types of illnesses (including GBS and myocarditis) are often either infectious or post-infectious syndromes. That means they are caused by the inflammation brought about by an active infection, or they are an auto-immune inflammatory response that follows an infection. The post-infectious auto-immune response is often caused by molecular mimicry, which means that an antigen on the infecting organism (virus or bacteria) looks very similar to a self-antigen (on the coating around nerves for GBS or in the heart muscle for myocarditis, for example). The immune system then starts to target the self-antigen, because it looks too much like the viral or bacterial antigen.

This is likely the case with myocarditis following mRNA vaccinations as well. Rare individuals, due to genetic variation, have cardiac self-antigens that are similar to the spike protein targeted by the COVID vaccines. This causes the inflammation provoked by the vaccine to target the heart muscle, causing the myocarditis. But in this case the heart antigen must only be a little similar to the spike protein, because the inflammatory response is mild and transient.

The science regarding the mRNA vaccines and myocarditis is reassuring – this is a rare and mild side effect. Meanwhile, COVID is a potentially deadly disease, and is far more likely to produce myocarditis as a side effect that the vaccines that prevent COVID. But of course it takes a lot less mental energy to watch a video online and react with fear, than to wade through the scientific evidence and make an informed risk vs benefit assessment.