Every fall, the reminders to get a flu shot can become so pervasive they can be easily ignored: “Yeah, yeah,” you say. “I need to get my flu shot, but I’ll do it tomorrow.” But what if scientists could prove that getting your flu shot could significantly reduce the likelihood of developing Alzheimer’s disease? Would that help break through the white noise?
Three studies presented at the 2020 Alzheimer’s Association International Conference (AAIC) today found that vaccinations indeed seem to significantly reduce the risk of Alzheimer’s.
The research on connections between vaccinations and Alzheimer’s was presented on the first day of the Alzheimer’s Association’s International Conference. Scheduled to be held in Amsterdam, the conference is instead being presented virtually and available to anyone for free. (Forewarning: the conference is very heavy on scientific lingo and fairly inaccessible for a non-medical audience.)
In one study presented today, researchers found that a one-time treatment with a flu vaccine was associated with a 17 percent reduction in Alzheimer’s disease. More frequent vaccinations cut Alzheimer’s incidence by a further 13 percent. Another study found that vaccination against pneumonia for people between ages 65 and 75 reduced Alzheimer’s risk by up to 40 percent for some people.
And for those with dementia, getting those flu shots could make a life-or-death difference. Another study found that people with dementia are six-times more likely to die from flu-like diseases.
“With the COVID-19 pandemic, vaccines are at the forefront of public health discussions,” Maria C. Carrillo, chief science officer for the Alzheimer’s Association, said in a news release. “It is important to explore their benefit in not only protecting against viral or bacterial infection but also improving long-term health outcomes.”
While the new research is preliminary, Carrillo said it calls for “further studies in large, diverse clinical trials to inform whether vaccinations as a public health strategy decrease our risk for developing dementia as we age.”
Seasonal Flu Vaccine May Reduce Incidence of Alzheimer’s Dementia
While earlier research has suggested that vaccinations might help protect against cognitive decline, the Alzheimer’s Association said there have been no large, comprehensive studies specifically focused on the influenza (flu) vaccine and Alzheimer’s disease risk.
A team led by Albert Amran, a medical student at McGovern Medical School at the University of Texas Health Science Center at Houston, sought to fill that gap by investigating a 9,000-record dataset from all over the United States.
In his research, Amran found that one flu vaccination was associated with a lower prevalence of Alzheimer’s, and that patients receiving the flu vaccine more frequently was associated with an even lower prevalence of Alzheimer’s.
Put simply, consistently getting an annual flu shot seemed to lead to a reduced risk of Alzheimer’s disease for patients between the ages of 75-84.
The researchers also found that getting a first vaccination at a younger age — 60 instead of 70, for example — seemed to protect best against Alzheimer’s.
“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,” Amran said.
Pneumonia Vaccine May Reduce Alzheimer’s Risk Later in Life
Another study found that repurposing existing vaccines may be a promising approach to Alzheimer’s disease prevention.
Svetlana Ukraintseva, an associate research professor at Duke University, found ties between pneumococcal vaccination — with and without an accompanying seasonal flu shot — and the risk of Alzheimer’s disease among more than 5,000 participants from a cardiovascular health study.
The researchers found that pneumococcal vaccination between ages 65-75 reduced risk of developing Alzheimer’s by 25 to 30 percent. The largest reduction in the risk of Alzheimer’s (up to 40 percent) was found among people vaccinated against pneumonia who were non-carriers of a gene known to be tied to a risk for developing Alzheimer’s.
A pneumococcal vaccine, Ukraintseva said, “may be a promising candidate for personalized Alzheimer’s prevention, particularly in non-carriers of certain risk genes.”
Infection Substantially Increases Mortality in People with Dementia
People living with dementia commonly experience other health conditions including viral, bacterial, and other infections. A study by Janet Janbek of the Danish Dementia Research Centre, Rigshospitalet, and the University of Copenhagen in Denmark, found that people with dementia who were hospitalized because of an infection were 6.5 times more likely to die.
While the death rate was highest within the first 30 days following the hospital visit, the researchers found that mortality rates remained elevated for 10 years after the initial infection-related hospitalization.
“Our study supports the need to to find out why infections are linked to higher mortality in people with dementia, specifically which risk factors and biological mechanisms are involved,” Janbek said. “This will help advance our understanding of the role of infections in dementia.”