In the largest global study on vaccine safety to date, researchers have uncovered potential links between COVID-19 vaccines and rare neurological, blood, and heart-related issues, albeit with small increases in risk. The study, which involved 99 million people across 8 countries, raises concerns about the side effects of these vaccines.
Although COVID-19 vaccines have demonstrated effectiveness in preventing severe illness, deaths, and long-term symptoms of the virus, worries have emerged regarding their potential adverse effects.
Specifically, Pfizer Inc., BioNTech SE, and Moderna Inc. developed mRNA vaccines that have been associated with a higher risk of heart-related inflammation, notably myocarditis, following the first, second, and third doses. The risk appears more pronounced after the second dose of the Moderna vaccine.
Moreover, certain doses of the Moderna vaccine have been linked to an elevated risk of pericarditis and inflammation of the sac surrounding the heart.
READ ALSO — World Bank: 25% of Pakistan’s Population Living Below Poverty Line
Viral-vector vaccines, such as the one from the University of Oxford produced by AstraZeneca Plc, have shown associations with specific adverse events. These include an increased risk of cerebral venous sinus thrombosis, a type of blood clot in the brain, and Guillain-Barre syndrome. In this neurological disorder, the immune system mistakenly attacks the peripheral nervous system.
Notably, the Oxford-developed vaccine has been tied to a significant rise in Guillain-Barre syndrome cases compared to mRNA vaccines.
Additionally, potential safety signals for conditions like transverse myelitis and acute disseminated encephalomyelitis, characterized by spinal cord and brain inflammation, respectively, were observed following both viral-vector and mRNA vaccines.
In a separate study by the Yale School of Medicine, over 240 adults experiencing chronic post-vaccination syndrome reported symptoms such as exercise intolerance, excessive fatigue, numbness, and cognitive difficulties. However, the exact cause of this syndrome remains unknown, and standardized diagnostic tests or treatments are currently unavailable.
Principal investigator Harlan Krumholz from the Yale New Haven Hospital Center for Outcomes Research and Evaluation stressed the importance of understanding these adverse events to alleviate suffering and enhance vaccine safety. While vaccines have undoubtedly saved many lives, addressing the concerns of individuals experiencing adverse effects is crucial.