“With exploding hearts, we see thee rise…”
This wasn’t on my list of things to write about…
An acquaintance asked me a few questions about vaccines. She then mentioned having heard about “hearts exploding” after vaccination.
Now, from time to time, I had heard about some cases of heart inflammation after vaccination with MRNA (Pfizer, Moderna) vaccines, particularly among young males. That sounds serious enough (even without the “exploding” part) but I really didn’t know anything about it.
So I did some looking around. Here’s what I’ve found.
We are talking about myocarditis, pericarditis, or myopericarditis. Those are long medical words meaning inflammation of different areas of the heart. The US CDC says:
Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the outer lining of the heart
It may not surprise you to learn that Myopericarditis is inflammation of both.
Oh, we should also note that these inflammations have not been proven to have been CAUSED by the vaccinations. These inflammations can also be caused by… wait for it… COVID-19. So you could have someone who got COVID-19 and also got an MRNA vaccination and then got heart inflammation. You wouldn’t really know what caused it (maybe neither did).
Anyway, is inflammation serious?
What is
Inflammation: the body's natural response to protect itself
Acute inflammation is short term, like when you bang your knee or cut your finger. Your immune system creates visible redness and swelling as part of the healing process.
It’s also acute inflammation if you have an infection like the flu or pneumonia.
So, inflammation is a natural body function. It can be mild. It can be serious.
Heart inflammation post-MRNA vaccination
From the USA:
Use of mRNA COVID-19 Vaccine After Reports of Myocarditis Among Vaccine Recipients: Update from the Advisory Committee on Immunization Practices — United
In the US, as of June, approximately 52,000,000 vaccine doses had been given to persons aged 12–29.
323 were confirmed to have had myocarditis, pericarditis, or myopericarditis
None died.
Per 1,000,000 second doses given to males aged 12–29, 11,000 COVID-19 cases could be prevented, compared with 39–47 expected myocarditis cases.
This analysis did not include the potential benefit of preventing post-COVID-19 conditions, such as prolonged symptoms and MIS-C.
Canada (up to July 9, 2021)
Myocarditis and Pericarditis following COVID-19 mRNA Vaccination: Practical Considerations for Care
163 cases of myocarditis/pericarditis after vaccination
These clinical findings are similar to multiple series reported worldwide.
12.6 cases per 1,000,000 second doses in the 12-39 year-old age group
Severe cases exceedingly rare
Mild symptoms in the overwhelming majority of cases, do not usually require specific interventions
So, let’s look at the Canadian numbers.
Up to July 9:
- 16,045,371 people in Canada had been fully vaccinated
- there had been 163 cases of heart inflammation.
That’s .001% of people vaccinated who got non-lethal mild heart inflammation (that resolved itself).
Let’s compare that to people in Canada who got COVID
Up to July 9
- Canada’s population was 38,067,913
- 1,427,582 people had confirmed cases of COVID-19
That’s 3.75% of the population who got infected.
So, you were 3,750 times more likely to get COVID than to get non-lethal mild heart inflammation after vaccination.
How about deaths?
Up to July 9
- 26,420 people in Canada had died from COVID-19
That’s .069% of the population.
So, you were 690 times more likely to DIE from COVID than to get non-lethal mild heart inflammation.
COVID-19 Vaccine safety updates
Advisory Committee on Immunization Practices (ACIP)
Further Reading
Myocarditis With COVID-19 mRNA
Almost all cases resolved with or without treatment.
The Link Between Myocarditis and COVID-19 mRNA
Cases of heart inflammation post-vaccination are usually mild and get better quickly,
Myocarditis can be caused by a variety of common viruses
Though rare, myocarditis can be caused by an immune response to a vaccine such as the smallpox vaccine, which was the most successful vaccine in world history.
Too early to tell what may be causing the recently reported myocarditis cases
An incredibly rare event,
Unknown whether COVID-19, is more likely to cause myocarditis than other viruses
Myocarditis With COVID-19 mRNA
myocarditis/pericarditis rates are ≈12.6 cases per 1,000,000 doses of second-dose mRNA vaccine among individuals 12 to 39 years of age
New information for parents on myocarditis and COVID-19
COVID-19 can affect the heart, too — not only as part of MIS-C, a multisystem inflammatory complication of COVID-19 seen in children, but also just from the infection itself. COVID-19 can cause heart damage, including myocarditis.
The risk is small — and the benefits are huge.