Could our risk of getting Alzheimer's disease be lowered by something as simple as getting flu and pneumonia vaccines? Two large observational studies suggest just that.
The studies, which were presented at this year's Alzheimer's Association International Conference (AAIC), found that: getting a flu vaccine (with more than one flu shot over the years even better), getting the flu vaccines at a younger age, and additionally getting the pneumonia vaccine between the ages of 65 and 75 years were all associated with a lowered risk of Alzheimer's disease. It's as if they somehow were brain protective.
Excerpts from Medscape: Flu, Pneumonia Vaccination Tied to Lower Dementia Risk
In a cohort study of more than 9000 older adults, receiving a single influenza vaccination was associated with a 17% lower prevalence of AD compared with not receiving the vaccine. In addition, for those who were vaccinated more than once over the years, there was an additional 13% reduction in AD incidence.
In another study, which included more than 5000 older participants, being vaccinated against pneumonia between the ages of 65 and 75 reduced the risk of developing AD by 30%.
"While these are very preliminary data, these studies do suggest that with vaccination against both respiratory illnesses, there is the potential to lower risk for developing cognitive decline and dementia," said Edelmayer, who was not involved in the research.
The findings of both studies were presented at the Alzheimer's Association International Conference (AAIC) 2020, which was held online this year because of the COVID-19 pandemic.
The influenza vaccine study was presented by Albert Amran, a fourth-year medical student at McGovern Medical School at the University of Texas Health Science Center at Houston. The researchers used electronic health record data to create a propensity-matched cohort of 9066 vaccinated and unvaccinated adults aged 60 and older.
Influenza vaccination, increased frequency of administration, and younger age at time of vaccination were all associated with reduced incidence of AD, Amran reported.
Being vaccinated for influenza was significantly linked to a lower prevalence of AD in comparison with not being vaccinated. Receiving more than one vaccination over the years was associated with an additional reduction in AD incidence. The protection appeared to be strongest for those who received their first vaccination at a younger age, for example, at age 60 vs 70.
The other study was presented by Svetlana Ukraintseva, PhD, Duke University, Durham, North Carolina. The researchers investigated associations between pneumococcal vaccine, with and without an accompanying influenza vaccine, and the risk for AD among 5146 participants in the Cardiovascular Health Study.
In a logistic model with all covariates, vaccination against pneumonia between ages 65 and 75 was significantly associated with reduced risk of developing AD. Total number of vaccinations against pneumonia and influenza between ages 65 and 75 was also associated with a lower risk for AD. However, the effect was not evident for the influenza vaccination alone.
"The fact that very different pathogens ― viral, bacterial, fungal ― have been linked to AD indicates a possibility that compromised host immunity may play a role in AD through increasing overall brain's vulnerability to various microbes," Ukraintseva told Medscape Medical News.