The team, led by Drs. Paul E. Schulz and Avram S. Bukhbinder, compared the incidence of Alzheimer’s disease between patients with and without prior influenza vaccination in a large sample of adults aged 65 and over. The analysis reveals that influenza vaccination is associated with a reduced incidence of Alzheimer’s disease. Dr. Bukhbind comments on these findings: “We find that influenza vaccination in the elderly reduces the risk of developing Alzheimer’s for several years. The strength of this protective effect increases with the number of years the person has been vaccinated, in other words, the incidence rate of Alzheimer’s disease is lowest in people who are vaccinated. vaccinate every year.
Each flu vaccination reduces the risk of Alzheimer’s a little more
The study analyzed data from 935,887 flu-vaccinated patients and 935,887 unvaccinated patients. Regular consultations took place during the 4 years of follow-up:
- 5.1% of patients vaccinated against influenza developed Alzheimer’s disease;
- 8.5% of unvaccinated patients developed Alzheimer’s disease.
These results suggest the protective ability of influenza vaccination also against Alzheimer’s, however, the underlying mechanisms require further investigation. The authors recall previous studies that have already concluded on this specific effect of the flu vaccine and add: “The immune system is complex and certain infections, such as pneumonia, can activate it in such a way as to aggravate Alzheimer’s disease. Activating the immune system can indeed induce it to protect against Alzheimer’s disease. Obviously, we have yet to learn how the immune system worsens or improves Alzheimer’s-related outcomes.”
Is there a similar association between COVID-19 vaccination and Alzheimer’s disease risk? Is flu vaccination also associated with symptom severity in patients with dementia or Alzheimer’s? Answering these 2 questions is already the objective of future research.