Study of 99 million COVID-vaccinated people finds links to brain, heart problems

In what stands as one of the most comprehensive vaccine safety studies across the globe, scientists have singled out unusual conditions that have surfaced after receiving COVID-19 vaccinations.

The study of 99 million vaccinated people in eight countries found a slight increase in heart inflammation cases following shots from Pfizer and Moderna, both mRNA vaccines.

Simultaneously, the AstraZeneca vaccine, which uses a different technology known as a viral vector, has been associated with a rare brain blood clot disorder.

The AstraZeneca vaccine has also been linked to a higher risk of Guillain-Barre syndrome, a neurological disorder that can sometimes lead to muscle weakness and, in rare instances, paralysis.

These findings are particularly significant against the backdrop of the 13.5 billion doses of COVID-19 vaccines administered globally to date — an undertaking that has played a critical role in preserving lives during the pandemic.

The Global Vaccine Data Network’s exhaustive research, detailed in the scholarly journal Vaccine, provides expansive insight into the matter. The network’s publication, equipped with easy-to-navigate dashboards, transparently presents both its research methodology and the conclusions drawn for public examination.

The analysts involved in this study examined health data of 99 million individuals, primarily focused on 13 specific conditions considered to be of special interest for vaccine safety.

Evidence of myocarditis, which is inflammation of the heart muscle, was particularly recurrent among individuals after their first, second, or booster dose of an mRNA vaccine.

Modest spikes in incidence were noted especially following the administration of the second dose of the Moderna shot, which was also tied to a raised occurrence of pericarditis — a swelling of the tissue surrounding the heart — after initial and booster vaccinations.

A significant increase in the cases of Guillain-Barre syndrome was observed within 42 days of receiving the initial dose of AstraZeneca’s vaccine, also known as Vaxzevria.

The study documented an increase to 190 cases from the forecasted 66 based on natural incidence rates.

An uptick in cases of cerebral venous sinus thrombosis, an exceptionally rare type of cerebral clot, led to the restriction, or even discontinuation of the use of AstraZeneca’s vaccine in a number of countries, including Denmark.

Furthermore, a connection between this vaccine and myocarditis after the third dose was noted in specific demographics, albeit not as a widespread issue.

For more information, visit The Washington Times COVID-19 resource page.