Houston, TX—Here is a persuasive argument pharmacists can use to expand influenza vaccination rates: The shot will help protect you against Alzheimer’s disease.

That information is based on research studies presented at the recent Alzheimer’s Association International Conference. A team from The University of Texas Health Science Center at Houston determined that at least one flu vaccination was associated with a 17% reduction in Alzheimer’s incidence, while more frequent flu vaccination was associated with an additional 13% reduction in Alzheimer’s incidence.

Interestingly, vaccination against pneumonia was even more effective when provided to patients aged 65 to 75 years. It reduced Alzheimer’s risk by up to 40% depending on individual genes, according to researchers from the Duke University Social Science Research Institute in Durham, NC.

While previous research has suggested vaccinations may have a protective factor against cognitive decline, until now, there have not been large, comprehensive studies focused on the influenza vaccine and Alzheimer’s disease risk. Looking at medical records of more than 9,000 patients, the Texas team found having one flu vaccination was associated with a lower prevalence of Alzheimer’s disease (odds ratio 0.83, P <.0001), and among vaccinated patients receiving the flu vaccine more frequently was associated with an even lower prevalence of Alzheimer’s (odds ratio 0.87, P = .0342). Noting that those who received annual flu shots lowered their risk of Alzheimer’s the most, researchers calculated that regular vaccines meant an almost 6% reduced risk of Alzheimer’s disease for 16 years in patients between the ages of 75 and 84 years.

In addition, the protective association between the flu vaccine and the risk of Alzheimer’s appeared to be strongest for those who received their first vaccine at a younger age.

“Our study suggests that regular use of a very accessible and relatively cheap intervention—the flu shot—may significantly reduce risk of Alzheimer’s dementia,” said lead researcher Albert Amran, a medical student. “More research is needed to explore the biological mechanism for this effect—why and how it works in the body—which is important as we explore effective preventive therapies for Alzheimer’s.”

Svetlana Ukraintseva, PhD, led the Duke study, investigating associations between pneumococcal vaccination, with and without an accompanying seasonal flu shot. Included in the study were 5,146 participants aged 65 years and older from the Cardiovascular Health Study.

Taking a known genetic risk factor for Alzheimer’s—the rs2075650 G allele in the TOMM40 gene—into account, the study team found that pneumococcal vaccination between the ages of 65 and 75 years reduced the risk of developing Alzheimer’s by 25% to 30% after adjusting for sex, race, birth cohort, education, smoking, and number of G alleles.

The largest reduction in the risk of Alzheimer’s disease—up to 40%—was observed among noncarriers of the risk gene.

In their study, researchers determined that total number of vaccinations against pneumonia and the flu between ages 65 and 75 years was associated with a lower risk of Alzheimer’s, but that the effect wasn’t seen with the flu shot alone.

“Vaccinations against pneumonia before age 75 may reduce Alzheimer’s risk later in life, depending on individual genotype,” Dr. Ukraintseva said. “These data suggest that pneumococcal vaccine may be a promising candidate for personalized Alzheimer’s prevention, particularly in noncarriers of certain risk genes.”

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.

 « Click here to return to Weekly News Update.