Myocarditis, Pericarditis and mRNA Vaccines - An Association or a Cause?

A recent data release from a presentation at the Centers for Disease Control and Prevention provides COVID-19 vaccine consumers with some rather concerning data, particularly if they are under the age of 30.

  

Let's start with some background.  Here is a graph from the CDC showing the weekly number of COVID-19 deaths for the age group 15 years to 24 years in brown and 25 years to 34 years in turquoise:

 

Here is a table showing how many Americans of varying age groups have died from COVID-19, pneumonia or influenza:

 

Note that only 2,704 Americans under the age of 30 had deaths that "involved COVID-19" or less than 0.46 percent of "COVID-19-involved" deaths for all age groups.

In the latest COVID-19 Pandemic Planning Scenario from the CDC dated March 19, 2021, we find the following table:

 

Note that the best estimate infection fatality ratio (IFR) for children between the ages of 0 and 17 years is 0.002 percent (20/1,000,000) and for people between the ages of 18 and 49 years, the best estimate infection fatality ratio is 0.05 percent (500/1,000,000).

 

Now, let's switch subjects and look at some additional physiological background to help us put this posting into context.  Here are two definitions from the Mayo Clinic:

 

Myocarditis: 

 

Overview - Myocarditis is an inflammation of the heart muscle (myocardium). Myocarditis can affect your heart muscle and your heart's electrical system, reducing your heart's ability to pump and causing rapid or abnormal heart rhythms (arrhythmias).

 

A viral infection usually causes myocarditis, but it can result from a reaction to a drug or be part of a more general inflammatory condition. Signs and symptoms include chest pain, fatigue, shortness of breath, and arrhythmias.

 

Severe myocarditis weakens your heart so that the rest of your body doesn't get enough blood. Clots can form in your heart, leading to a stroke or heart attack.

 

Complications - Severe myocarditis can permanently damage heart muscles and cause the following:

 

1.) Heart failure. Untreated, myocarditis can damage your heart's muscle so that it can't pump blood effectively. In severe cases, myocarditis-related heart failure may require a ventricular assist device or a heart transplant.

2.) Heart attack or stroke. If your heart's muscle is injured and can't pump blood, the blood that pools in your heart can form clots. If a clot blocks one of your heart's arteries, you can have a heart attack. If a blood clot in your heart travels to an artery leading to your brain before becoming lodged, you can have a stroke.

3.) Rapid or abnormal heart rhythms (arrhythmias). Damage to your heart muscle can cause arrhythmias.

Sudden cardiac death. Certain serious arrhythmias can cause your heart to stop beating (sudden cardiac arrest). It's fatal if not treated immediately.

Here is a graphic showing myocarditis:

Pericarditis:

  

Overview - Pericarditis is swelling and irritation of the thin, saclike tissue surrounding your heart (pericardium). Pericarditis often causes sharp chest pain and sometimes other symptoms. The chest pain occurs when the irritated layers of the pericardium rub against each other.

 

Pericarditis is usually mild and goes away without treatment. Treatment for more-severe cases may include medications and, rarely, surgery. Early diagnosis and treatment may help reduce the risk of long-term complications from pericarditis.

 

Complications - Early diagnosis and treatment of pericarditis usually reduces the risk of the long-term complications. Complications of pericarditis include:

 

1.) Pericardial effusion. Pericarditis is usually associated with fluid around the heart, which can lead to more serious complications.

2.) Chronic constrictive pericarditis. Some people with long-term (chronic) pericarditis develop permanent thickening and scarring of the pericardium, which prevents the heart from filling and emptying properly. This unusual complication often leads to severe swelling of the legs and abdomen and shortness of breath.

3.) Cardiac tamponade. This life-threatening condition can develop when too much fluid collects in the pericardium. Excess fluid puts pressure on the heart and doesn't allow it to fill properly. Less blood leaves the heart, causing a dramatic drop in blood pressure. Cardiac tamponade requires emergency treatment.

Here is a diagram showing pericarditis:

 

Now, let's look at the recent data release from the CDC from a COVID-19 vaccine safety update presentation on June 23, 2021by the Vaccine Safety Team.  In this presentation, the author is looking at these two issues:

Here is a graph showing the preliminary reports of myocarditis/pericarditis for the mRNA vaccines by age and number of doses of vaccine:

 

Here are the symptoms experienced by the individuals under the age of 30:

 

Here is a graphic showing the number of cases of myocarditis/pericarditis following dose 2 of the mRNA vaccines for both males and females for all age groups.  Note that the "expected" column is based on  a U.S. population-based background incidence rate of myocarditis/pericarditis that was used in the safety assessment of the COVID-19 vaccines:

 

As you can see, among males under the age of 40 who have received the second mRNA vaccination, there is a significantly higher number of cases of myocarditis/pericarditis than expected, particularly among those between the ages of 12 and 24 (inclusive).  The background rate would have predicted between 1 and 12 case of myocarditis/pericarditis for this age group, however, real world reports to the CDC's Vaccine Adverse Event Reporting System (VAERS) observed 347 cases or 28.9 times more cases than predicted.

 

Let's close this posting with a quote from this recent article found in the British Medical Journal dated June 23, 2021:

"On 23 June the US Centers for Disease Control and Prevention’s safety committee said there was a “likely association” between the Pfizer-BioNTech and Moderna covid-19 vaccines and myocarditis and pericarditis in some young adults. The CDC’s Advisory Committee on Immunization Practices said there was a higher than expected number of reports of heart inflammation in people aged 16-24 who had received the mRNA vaccines but that the benefits of vaccination still clearly outweighed the risks.

The Vaccine Adverse Event Reporting System (VAERS) had received 1226 preliminary reports of myocarditis and pericarditis after about 300 million doses of the Pfizer and Moderna vaccines up to 11 June. The US Food and Drug Administration said it would add a warning about the risk to information sheets for the mRNA covid vaccines. A joint statement signed by the US Department of Health and Human Services, the CDC, and medical organizations such as the American College of Physicians and American Medical Association emphasized that the side effect was “extremely rare” and that most cases were mild.

In the US the confirmed cases have mostly been seen in male adolescents and young adults and occur more often after the second dose than the first. CDC data showed that after 3 625 574 second doses administered to men aged 18-24 there were 233 reports of myocarditis or pericarditis, when two to 25 would have been expected. After 5 237 262 doses administered to women in this age group 27 cases were seen, against an expected two to 18. Vinay Prasad, a haematologist-oncologist and associate professor in the department of epidemiology and biostatistics at the University of California San Francisco, told The BMJ “There is a clear and large safety signal in young men and a clear but small signal in young women as well.”

 

While the USDA will add a warning to the mRNA COVID-19 vaccine information sheets, it is highly unlikely that these sheets will be seen by any of the young Americans being vaccinated.

While this may seem like a small number of cases given the millions of COVID-19 vaccine doses that have been administered to young Americans, the occurrence of myocarditis has the potential to result in a life-changing, negative health situation for an age group that had a negligible risk of dying from COVID-19 in the first place.  For the youngest among the mRNA vaccine recipients, the occurrence of vaccine-related myocarditis could have a very palpable impact on their parents as well.  While it is still unclear whether this serious adverse event is caused by the mRNA vaccines or merely associated with them, the purpose of vaccines is to benefit the person who gets it and not result in "net harm".