Explained: What is vaccine-related myocarditis and should you be worried about it?

According to the Centres for Disease Control and Prevention, myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the lining outside the heart.

In both cases, the body’s immune system causes inflammation in response to an infection or some other trigger.

In their most severe and rare forms, myocarditis and pericarditis can result in chronic heart failure or even death.

Experts state that in the vast majority of cases, myocarditis goes away without permanent complications. However, if severe, the condition may permanently damage heart muscles or lead to sudden cardiac death.

But is there a link between myocarditis and Covid vaccines?

There is a range of things that could trigger myocarditis, but most often it’s said to be viruses such as the common cold or Covid.

There have been a few reports of people suffering from the condition after taking the Covid vaccine, although some experts are of the opinion that the risk to heart health is dramatically increased by contracting the virus and not by having the jab.

To study this, a Denmark study reportedly investigated the rate of myocarditis within 28 days of vaccination against Covid-19.

Data from around five million people were included in the study, which included people aged over 12 years from October 2020 to October 2021.

However, only the Pfizer and Moderna Covid vaccines proceeded to the final analysis, as AstraZeneca and Johnson & Johnson were reportedly removed from Denmark’s national vaccination program.

Researchers found that those participants vaccinated with Moderna had a slightly higher rate of myocarditis in comparison to unvaccinated controls, however, Pfizer only had a higher rate for female participants but not the male participants when compared to the control groups, the Mirror reports.

Moderna also reportedly had a higher rate in the 12-39 age group, although it was found that Pfizer did not reach statistical significance compared to controls.

Yet, the occurrence of myocarditis was still found to be low in patients who were vaccinated.

“Although the Moderna vaccine demonstrated a significantly increased rate of myocarditis, the absolute rate was low (4.2 and 1.4 per 100,000 individuals in 28 days post-Moderna and Pfizer vaccines, respectively) and that the benefits of vaccination should be considered when interpreting these findings,” the researchers add.

The British Heart Foundation states, “Treatment for myocarditis usually depends on the cause.

“It can involve close monitoring and medication, including anti-inflammatory medicines and antibiotics.”

Most of the reported cases of myocarditis that were linked to mRNA, which is the Moderna vaccination have reportedly required hospital assessment and monitoring due to the extremely rare complication of sudden death.

The Medicines & Healthcare products Regulation Agency (MHRA) in the UK utilizes the voluntary Yellow Card system for reporting suspected adverse effects to vaccines.

It states: “Whilst we cannot infer causality from results of the Yellow Card scheme, it has suggested an association between COVID vaccination and myocarditis and pericarditis.”

The British Heart Foundation explains, “In some cases, myocarditis can affect your heart's electrical system, stopping it from pumping properly.”

Myocarditis can also be triggered by some conditions including bacterial infections, autoimmune conditions, or due to some fungi or parasites.

Signs of the condition may include:

• A stabbing pain and/or tightness in the chest which may spread across the body

• Flu-like symptoms such as a high temperature, tiredness, and fatigue

• Shortness of breath with light exercising or walking

• Difficulty breathing when resting

• Palpitations or an abnormal heart rhythm.

A study in the US discovered that up to 6% of viral myocarditis cases in adolescents had required a heart transplant, or resulted in death, the Mirror informs.