A comprehensive study involving nearly 100 million people vaccinated against COVID-19 has confirmed the association of the vaccines with certain side effects, such as myocarditis and Guillain-Barré syndrome, echoing earlier findings.
The analysis highlighted that the risk of these conditions is higher following coronavirus infection than from vaccination, emphasizing the importance of evaluating the benefits of immunization against its risks.
Conducted by the Global COVID Vaccine Safety project, the research encompassed data from 99,068,901 individuals in eight countries, focusing on adverse reactions after receiving Pfizer (NYSE:PFE), Moderna (NASDAQ:MRNA), and AstraZeneca (NASDAQ:AZN) vaccines.
The study sought to identify 13 specific adverse events within 42 days post-vaccination, including Guillain-Barré syndrome, Bell’s palsy, convulsions, myocarditis, and pericarditis.
Recipients of the AstraZeneca vaccine showed a marked increase in Guillain-Barré syndrome cases within 42 days of vaccination, the study found.
Moreover, an unexpected rise in acute disseminated encephalomyelitis (ADEM) cases, a condition causing inflammation in the brain and spinal cord, was observed after the first dose of Moderna’s vaccine.
However, the findings regarding ADEM showed “no consistent pattern in terms of vaccine or timing following vaccination, and larger epidemiological studies have not confirmed any potential association.”
The study also found a significant uptick in myocarditis cases, particularly following the Pfizer and Moderna mRNA vaccines, consistently across the first, second, and third doses.
Further, instances of pericarditis were significantly higher than anticipated after the first and fourth doses of Moderna’s vaccine.