Covid vaccines linked to rare heart and brain disorders, says vaccine study

A woman receives a dose of Pfizer vaccine for Covid-19 at a pharmacy. File Picture: Pascal Pochard-Casabianca / AFP

A woman receives a dose of Pfizer vaccine for Covid-19 at a pharmacy. File Picture: Pascal Pochard-Casabianca / AFP

Published Feb 21, 2024


A recent peer-reviewed study has revealed rare occurrences of heart, brain, and blood disorders associated with Covid vaccines from companies such as Pfizer, Moderna, and AstraZeneca.

This comes after concern mounts about the uptick in Covid-19 infections abroad, and the Gauteng Department of Health slamming claims that people who were vaccinated against Covid-19 are believed to be dying.

The study was conducted by researchers from the Global Vaccine Data Network who analysed data from 99 million vaccinated individuals across eight countries. This makes it the largest Covid vaccine study to date.

The Global Vaccine Data Network is the research arm of the World Health Organization.

Key findings from the study

The study found rare cases of myocarditis, which in basic terms is the inflammation of the heart. Cases of myocarditis were identified after the administration of Pfizer-BioNTech’s and Moderna’s mRNA vaccines, with the highest rate observed after the second Moderna dose.

Another heart condition called pericarditis showed an increased risk in those who received a third dose of AstraZeneca’s viral-vector vaccine, as well as specific doses of Moderna’s vaccine. Pericarditis refers to the swelling and irritation of the thin, sac-like tissue surrounding the heart.

The risk of developing the rare autoimmune disorder Guillain-Barre syndrome was higher among those who received AstraZeneca’s vaccine, compared to the expected rate, in addition to an increased risk of blood clots.

Neurological disorders such as acute disseminated encephalomyelitis showed an increased risk following the administration of Moderna’s and AstraZeneca’s vaccines.

Despite these alarming findings, experts stress that the risks associated with Covid-19 infection far outweigh the risks of vaccination.

Experts also highlight that the risk of neurological events following a Covid infection is significantly higher compared to vaccination. Furthermore, studies have shown that the risk of developing myocarditis and Guillain-Barre syndrome is higher post-infection than after vaccination.

As of now, approximately 13.5 billion Covid vaccines have been administered worldwide. Vaccines from Moderna, Pfizer-BioNTech, and AstraZeneca have proven effective in preventing severe illness, hospitalisations, and death.