COVID-19 Vaccine Side Effects Linked to Serious Heart Problems and Autoimmune Disorder

Revelations come as HHS Secretary Robert F. Kennedy, Jr. has announced his agency will no longer recommend the vaccines for children or pregnant women.

Federal health officials are recommending updated warning labels on some COVID-19 vaccines, including those from Pfizer and Moderna, indicating that side effects could lead to an increased risk of serious heart conditions.

The safety label changes were announced in letters sent by the U.S. Food and Drug Administration (FDA) in April to Pfizer (PDF) and Moderna (PDF), indicating that both companies should update their vaccines’ warnings labels over the risk of myocarditis and pericarditis side effects.

Myocarditis and pericarditis are each a kind of inflammation involving the heart. Myocarditis is an inflammation of the heart muscle itself, also known as the myocardium, while pericarditis is an inflammation of the pericadum, which is a thin membrane surrounding the heart.

Although the two kinds of inflammation are not always severe, they can lead to serious heart damage, which can increase an individual’s risk of heart failure, arrhythmia, stroke or heart attack.

In the case of the Pfizer vaccine and the Moderna vaccine, the FDA is requiring an updated label change, following further research into myocarditis and pericarditis side effects linked to the two products.

Prior research had led to warning labels indicating that cases of myocarditis and pericarditis among vaccine recipients were highest for males aged 18 through 24. However, the FDA will now require that the warning labels point out that the two conditions most commonly occur between one and seven days after the vaccines’ administration in those aged 6 months through 64 years old, with approximately eight cases per 1 million doses.

COVID-19 Vaccines and Autoimmune Disorder

In addition to updated warning labels being added to the Pfizer and Moderna vaccines, further research has also linked COVID-19 vaccine side effects to the increased risk of a rare autoimmune disorder, known as Guillain-Barré syndrome (GBS).

In a study published in the July 11 issue of the science journal Vaccine, an international team of researchers investigated the risk of Guillain-Barré syndrome after COVID-19 vaccination and SARS-CoV-2 infection.

Guillain-Barré syndrome is a rare neurological condition, which can affect the arms, legs, facial muscles and even the muscles used for breathing. Although the precise cause is often unclear, GBS usually follows an infection, surgery or vaccination. Most individuals recover, but the process can take weeks to years and may require intensive medical support. 

A team of researchers, led by Jeffrey C. Kwong of the University of Toronto in Canada, found an increased risk of Guillain-Barré syndrome within 42 days of COVID-19 vaccination with the AstraZeneca vaccine, which is a kind of adenoviral vaccine.

However, the Pfizer vaccine, which is a type of mRNA vaccine, resulted in a reduced risk of GBS for those who received the shot compared to those who suffered from a SARS-CoV-2 infection.

These findings led the researchers to conclude that mRNA COVID-19 vaccines may not carry the same risk of GBS as adenoviral vaccines.

No COVID Vaccines Recommended for Children, Pregnant Women

Amid these increased concerns regarding COVID vaccines, U.S. Department of Health and Human Services (HHS) secretary, Robert F. Kennedy, Jr., announced that his agency will no longer be recommending the vaccines for children and pregnant women.

The announcement was made via a video posted to the social media platform X (formerly Twitter), in which Kennedy stated that the vaccines would be removed from the U.S. Centers for Disease Control and Prevention’s (CDC) immunization schedule for those two groups.

Kennedy has a history of skepticism with regard to vaccines, which some medical professionals believe could lead to dangerous results for at-risk individuals.