Researchers might have found cause of Covid vaccine myocarditis after study reveals jab lowered death rate

Researchers think they've found the cause of myocarditis associated with the Covid vaccine after a new study found that the jab lowered the death rate.

Myocarditis is inflammation of the heart muscle, which can often follow viral infection. It can develop suddenly, and can recur, or even be chronic.

While most people can recover from myocarditis, for others, if the inflammation is severe, it can lead to the heart having to work harder, making it weaker.

According to the British Heart Foundation, there is a link between myocarditis and pericarditis (inflammation of the heart’s lining) and the Covid vaccine, although reports are rare.

In a new study, scientists have revealed what they believe could have driven cases of myocarditis, discovering a pair of immune signals they think are responsible.

Researchers think they've found the cause of myocarditis associated with the covid vaccine (Getty Stock Photo)

Also known as cytokines, these molecules were present at higher levels in the blood of individuals who developed myocarditis after vaccination.

Scientists found that the signals - CXCL10 and interferon-gamma - could be created in labs when mice were vaccinated with the vaccines.

The team discovered that blocking the signals with antibodies reduced these symptoms in mice and in structures that mimic the human heart.

The study, published in the Science Translational Medicine journal, also discovered that genistein, found in legumes, could help reduce inflammation.

“I want to emphasize this is very, very rare. This study is purely to understand why. In those rare cases, what’s going on? People talk about it, and here we provide a mechanism,” Joe Wu, director of Stanford Cardiovascular Institute and study author, told Stat News.

Meanwhile, Kathryn Edwards, professor emerita at Vanderbilt University, also explained that mouse studies can often come with limitations.

Wu explained that the research team in this particular study had to use higher vaccine doses to ensure that myocarditis developed. The event was so rare that it would have taken 20,000 mice to come across the findings.

Covid first began in 2020 (Getty Stock Photo)

The British Heart Foundation also said that the Covid virus was more likely to cause myocarditis than the vaccine itself.

Around 7,102,614 people worldwide are understood to have died from Covid, with 227,000 people in the UK having the disease listed as their cause of death, the BBC reports.

The vaccine rollout was widely successful, with an estimated 67 per cent of the world's population having received a COVID-19 vaccine by December 2023, according to the WHO.

However, it wasn't without its problems. Online misinformation led to growing mistrust in the vaccine, while cases of rare side effects associated with the drug also raised concerns.

Despite this, the vaccine was found to be highly effective in reducing theCOVID-19 mortality rate.

Published in the journal JAMA Network Open, researchers compared vaccinated and unvaccinated adults in France between the ages of 18 and 59. They found a 25 per cent lower risk of all-cause mortality among participants who'd been vaccinated.

A total of 22.7 million vaccinated individuals and 5.9 million unvaccinated people - around 40 per cent of France's total population - took part in the study.

The study also revealed that vaccinated adults had a 74 per cent lower risk of dying in hospital from Covid complications.