Recent research suggests that regular vaccination against influenza and other infectious diseases (such as shingles, pneumococcal pneumonia, tetanus, diphtheria, and whooping cough) may reduce the risk of Alzheimer’s disease and related dementias.
Several studies have found that people who are vaccinated against the flu and other infectious diseases appear to be less likely to develop dementia than unvaccinated people, although scientists aren’t sure why.
Some believe that infectious agents play an important role in the development of Alzheimer’s disease, and that vaccines can help prevent or reduce the chance of contracting these infections.
“Vaccines are the great public health success of our generation. They protect you against a wide range of infections, many of which can be life-threatening. Now it appears there is another vaccine for one of the most feared diseases. A huge benefit,” Paul E. Schulz, professor of neurology and director of the Center for Neurocognitive Disorders at McGovern Medical School at UTHealth Houston, told The Washington Post. .
More information about studies on the benefits of the flu vaccine
Schultz, an investigator on several of the studies, commented that the vaccine could block the immune system’s response to amyloid plaques, a naturally occurring protein found in Alzheimer’s disease. The content is unusually high.
He explained that the immune system sees plaques as foreign invaders and attacks them, causing chronic brain inflammation and the death of nearby neurons, leading to dementia.
By suppressing the immune response to amyloid, the vaccine can save brain cells that the body’s immune system would otherwise kill. Vaccines also have the potential to enhance the immune system’s ability to clear plaque.
“Less plaque leads to less inflammation and less brain cell loss. We’re still not sure what the exact mechanism is, but there’s something going on in the brain and immune system that seems to be producing a lot of damage,” Schultz said. Big impact. “
What do you know about immunization?
Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine and co-director of the Center for Vaccine Development at Texas Children’s Hospital, said the studies “suggest that the long-term benefits of vaccine immunity may exceed expectations” from direct effects. “
It’s unclear why the vaccine slows or prevents dementia, Hotez said.
“In some cases, they prevent viruses from causing neurological damage directly, particularly in the case of neurotropic viruses, or indirectly through pathogen-induced brain inflammation. In other cases, they stimulate innate immune mechanisms , thereby preventing the chain of events leading to dementia,” he commented.
data
In the influenza study, researchers drew two groups of 935,887 people from a national patient database, one vaccinated and the other unvaccinated.
To avoid the influence of various factors that could influence the results, the scientists made sure that each group had many of the same characteristics, such as age, gender, frequency of doctor visits, and certain medical conditions, such as high blood pressure. Stress and high cholesterol.
Schultz and his colleagues found that getting an annual flu shot for three years reduced the risk of dementia by 20 percent over the next four to eight years, while six shots doubled the risk. , reaching 40%.
Schultz explained that there were 47,889 cases of dementia in the vaccinated group compared to 79,630 cases in unvaccinated participants, a difference of more than 30,000 cases.
