“Vaccines are the great public health success story of our generation,” he said. Paul E. Schulz, professor of neurology and director of the Center for Neurocognitive Disorders at McGovern Medical School at UT Health Houston, has led several studies. “They protect you from any potentially life-threatening infections. And now there appears to be another tremendous benefit, this one against the most feared diseases.”
a number of the study People vaccinated against influenza and some other infectious diseases appear to be less likely to develop dementia than unvaccinated people, and scientists aren’t sure why. The researchers found that this is not the case.Some people believe that infectious agent It is believed that vaccinations may play a role in the development of Alzheimer’s disease and help prevent or reduce the likelihood of contracting these infections.
Alternatively, Schulz speculates that the vaccine could suppress the immune system’s response to amyloid plaques, a naturally occurring protein found in unusually high levels in Alzheimer’s disease. The immune system treats plaques as foreign invaders and attacks them, causing chronic brain inflammation and death of nearby neurons, contributing to dementia, he said.
In quelling the immune response to amyloid, the vaccine could save brain cells that the body’s immune system might otherwise kill, he said. It’s also possible that the vaccine strengthens the immune system’s ability to clear plaque. “When you have less plaque, you have less inflammation and less brain cell loss,” Schultz said, adding, “We still don’t know exactly what the mechanism is, but something happens in the brain and immune system. It’s happening and it seems to be causing a big problem.” difference. “
peter hotezDean 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 study shows that “the long-term benefits of vaccine immunization exceed the intended immediate benefits.” This suggests that there is a possibility that it may be exceeded.” ”
Hotez said it’s unclear why vaccination slows or prevents the progression of dementia. “In some cases, it may specifically prevent the virus from causing neurological involvement. neurotropic virus, or indirectly through brain inflammation that can be caused by pathogens,” he said. “In other cases, they may stimulate the innate immune system and protect against the cascade of events that lead to dementia.”
Mr. Schultz recently study The study found a statistically significant difference in the incidence of Alzheimer’s disease after tracking the two groups (one vaccinated with influenza vaccine and the other unvaccinated) for up to eight years. found.
In the influenza study, researchers sampled participants from a national patient database and created two groups of 935,887 people each: one group was vaccinated and the other group was unvaccinated. Not vaccinated. To avoid the potential influence of different factors that could influence the results, the scientists made sure that each group had the same We tried to share many of the characteristics. Increased blood pressure and cholesterol.
Schultz and his colleagues found that getting the flu vaccine every year for three consecutive years reduced the risk of dementia by 20% over the next four to eight years, and six doses doubled the risk by 40%. .
Schulz said there were 47,889 people with dementia in the vaccinated group, compared to 79,630 in the unvaccinated participants, a difference of more than 30,000 people.
Similar results with other vaccines
somewhere else studyHis team found similar results with vaccines for other infectious diseases, including combinations for shingles, pneumococcal pneumonia, tetanus, diphtheria, and pertussis. Tdapor tetanus and diphtheria without pertussis components.
For example, for shingles vaccines (Zostavax, the earliest shingles vaccine, and Shingrix, the most recent shingles vaccine), researchers compared 198,847 vaccinated patients with the same number of unvaccinated patients. Schultz said the results were compared to patients in the United States. During 8 years of follow-up, 16,106 of the vaccinated patients developed Alzheimer’s disease, compared with 21,417 of the unvaccinated patients, or in the vaccinated group. There were 5,311 fewer patients with dementia.
Researchers compared two groups of 116,400 patients each, one vaccinated and one unvaccinated, using the Tdap and Td vaccines. Over eight years, 8,370 people developed dementia among vaccinated people, compared to 11,857 among non-vaccinated people and 3,487 fewer among vaccinated people.
For the pneumococcal vaccine, two groups of 260,037 people each were compared; one group was vaccinated, the other group was unvaccinated, but eight years later they were vaccinated. There were 20,583 people with dementia in the group, compared to 28,558 in the unvaccinated group, with 7,975 fewer people in the vaccinated group, Schulz said.
In two studies conducted in the United Kingdom (as yet unpublished and under peer review), Stanford University researchers found similar results.of beginningIt said the evidence suggests that among older people in Wales, vaccination with Zostavax prevented an estimated one in five new cases of dementia over seven years. Pascal Gertsetzeran assistant professor of medicine in the Department of Primary Care and Population Health at Stanford University, led the study.
of Number 2 An analysis of mortality data from England and Wales found a 5 percentage point difference in the odds of dying from dementia over nine years of follow-up, or one in 20 deaths avoided.
In both studies, scientists established two groups for comparison purposes based on countries’ date of birth eligibility requirements. People who turned 80 just before the program started were not eligible for the vaccine and remained ineligible, but people who turned 80 just after the program started were vaccinated for free for the next year.
“While the only difference between the two comparison groups may have been a small difference in age, there was a large difference in the odds of receiving the shingles vaccine,” Gertsetzer said. “As such, our study is fundamentally different in approach from studies that simply compare people who were vaccinated with those who were not vaccinated. The findings from this unique natural randomization We think this strongly suggests a causal relationship.”
Experts said more research was needed to determine how vaccines affect the brain.
There are undetectable factors that differentiate vaccinated people from unvaccinated people, such as past head trauma, genetics, and environmental exposures, despite researchers’ efforts to control for them. He said it was possible. William Schaffnerprofessor of preventive medicine and infectious diseases at Vanderbilt University.
Either way, experts agree that people need to get vaccinated. “All of this requires further research, but vaccination and proper diet, exercise, and intellectual and emotional stimulation are important factors for healthy aging,” Hotez said.
Schaffner said no one should suffer from a preventable disease and “vaccination is an important way to stay healthy and live a healthy life.”
