Title: Covid Vaccine Associated with Slight Increase in Stroke Risk when Combined with High-Dose Flu Shot, FDA Analysis Suggests
Introduction
According to a recent analysis by the Food and Drug Administration (FDA), there appears to be a small increase in the risk of stroke when the Covid vaccine is administered alongside a high-dose flu shot. The analysis found that this link was most prominent in adults over the age of 85 and specifically applied to the Pfizer and Moderna bivalent Covid booster vaccines. Despite the findings, health officials emphasize that the risk remains minimal.
Stroke Risk Incidence
The FDA analysis revealed that there were approximately three strokes or stroke-like events called transient ischemic attacks for every 100,000 doses given when the high-dose flu shot was administered alongside the Pfizer and Moderna Covid booster vaccines. In comparison, the death rate from Covid among individuals over 85 in 2022 was 1,224 per 100,000. US health experts continue to emphasize the importance of vaccination, stating that the benefits outweigh the small risk.
Observational Studies
The studies conducted by health officials were observational, meaning they establish an association rather than a causal link. However, many scientists believe that the body’s inflammatory response to vaccines may trigger physiological changes that can potentially lead to stroke and seizures.
Possible Causes
The exact cause of why a vaccine may increase the risk of stroke remains uncertain, but researchers suggest several possibilities. Some studies indicate that shortly after receiving a Covid vaccine, individuals may experience a temporary increase in blood pressure, which could lead to damage to blood vessels and narrowing of arteries over time. Additionally, there is a potential risk of the vaccine causing a strong immune response that leads to inflammation and affects normal blood flow to the brain.
Risk with High-Dose Flu Shot and Covid Booster
The analysis found that individuals who received both the high-dose flu shot and the Moderna bivalent booster had a 35% increased risk of experiencing a transient or “mini” stroke. Meanwhile, those who received the flu shot and the bivalent Pfizer booster had a 20% increased risk. Further investigation into the link between stroke and flu vaccines alone among seniors found a nine percent increased risk of stroke. This suggests that the flu vaccine alone might be the primary driver of stroke risk.
COVID Infection vs. Vaccination Risk
In absolute terms, the risk of suffering a stroke following a Covid infection is significantly higher than the risk after receiving a booster shot. A study published in Nature Medicine in 2022 reported that individuals who survived the first 30 days of a Covid infection had a 52% increased risk of stroke and a 49% increased risk of a “mini stroke.”
Mitigating Risk
Health officials recommend spacing out vaccines by a few weeks and administering them in different arms to mitigate the potential risk of stroke. Researchers emphasize that the benefits of vaccination far outweigh the risk of severe illness and death.
Seizures in Children
In a separate analysis, the FDA found a tenuous association between seizures and Covid vaccinations in children aged two to five. The study, which assessed health data of more than 4.1 million American children, discovered that the risk of seizures slightly increased compared to rates in the general population. However, researchers cautioned that febrile seizures, commonly associated with fever, may have been recorded in the analysis.
Conclusion
While the FDA analysis highlights a small increase in stroke risk when the Covid vaccine is combined with a high-dose flu shot, health officials emphasize that the risk remains very low. Vaccination continues to be a crucial tool in combating the spread of Covid and protecting individuals from severe illness.