The University of Texas Health Sciences Center, UTHealth Houston, recently published the results of a study that found the flu vaccine reduced the risk of Alzheimer’s. The results are promising but little is known about the mechanisms behind this effect and thus how to exploit it.

Results of the study.
The study was conducted in the United States and found a 40% reduction in the odds of getting Alzheimer’s disease and getting the flu shot. Specifically, when the researchers analyzed the data, they discovered that 8.5% of those who were not vaccinated during the study period developed the disease, compared to 5.1% among those who received the vaccine.

The research team also observed an increased correlation between the doses of vaccines received and protection against the disease. As study co-author Avram Bukhbinder explains in a press release published by UTHealth, “The rate of getting Alzheimer’s was the lowest among those who received the vaccine each year.

More details on the research study.
Details of the study are now available in the journal Journal of Alzheimer’s Disease. More than two million profiles were analyzed in the study, which selected 935,887 vaccinated and a large number of unvaccinated participants. They were Americans over the age of 65. The study was followed for four years.

The technique used is known as Tendency Score Matching, a technique in which “pairs” of participants with similar characteristics are created. While this methodology is not considered as definitive as randomized controlled trials, it allows researchers to gain valuable insight into the effects of treatments.

Two years to find the possible link.
The possible relationship between the flu vaccine and resistance to Alzheimer’s is not entirely new. Two years ago, the UTH research team published the first results on this topic. On this occasion, they reviewed the medical records of more than 300,000 patients to investigate this relationship.

Albert Amran, then a student at UTHealth and co-author of both studies, explained that their theory was that flu virus proteins could “train” the body’s immune response, thereby protecting against Alzheimer’s. He also noted the need to further analyze the issue and conduct clinical trials to explore the flu vaccine as “a public health strategy for combating vaccines.” [el Alzheimer]”.

More preventive vaccines?
But these discoveries did not come alone. Also in 2020, two studies found similar links. One found that vaccination against pneumonia could reduce the incidence of Alzheimer’s by up to 40%, while another found that older people with dementia were much more likely to die after contracting an infection than those without dementia.

This led the team to further investigate the mechanisms that link vaccination against certain diseases with immunity against Alzheimer’s. “We think the flu vaccine has no particular effect,” explains Paul Schulz, another member of the research team. Schulz also acknowledged that they still have a lot to learn about how the immune system responds in these cases.

Another question that has yet to be clarified is whether the vaccine only helps to prevent Alzheimer’s or whether it also has a positive effect in the later stages of the disease.

Alzheimer’s disease.
Alzheimer’s is a disease that is estimated to affect approximately one million sick people in Spain, as well as 20% of people reaching the age of 80. It is associated with the death of neurons causing shrinkage and atrophy of the brain. It is an age-related disease that affects patients slowly and gradually.

Alzheimer’s has no cure and is a difficult disease to study because it affects the human brain. Therapies against the disease often focus on relieving their symptoms and controlling their development. A few experimental treatments are in testing, but it should always be taken into account that a good portion of them will go astray.

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