Can Alzheimer’s disease really be reduced by vaccines? Alzhiemer’s disease is an accumulation of brain proteins known as amyloid beta peptides that clump together forming plaques. These plaques collect between neurons and disrupt cell function, according to the National Institute of Aging. Vascular problems may also lead to a breakdown of the blood-brain barrier which protects the brain from harmful agents while allowing access for glucose and other nutrients. When this barrier is damaged, not only does it prevent glucose from entering the brain but it also prevents the clearing away of toxic beta amyloid and other harmful proteins which results in chronic inflammation and Alzheimers’s disease progression. Alzheimer’s disease accounts for 50-70% of dementia patients worldwide.
Well, there may be a simple thing that can be done to reduce the risk of this Alzheimer’s disease…vaccinations. I realize this is a hot topic especially in the past 3 years. But new research has provided yet one more reason to stay on top of our vaccinations in that it may decrease the risk of age-related cognitive decline.
Researchers performed a retrospective cohort study (an observational study) that included patients who did not have dementia during a 2 year period and were at least 65 years old. The groups, of 935,887 each, were obtained from a national patient database and had an 8 year follow up. They compared 2 similar groups of people, one vaccinated and the other non-vaccinated. They calculated the relative risk (risk of an outcome between exposed and unexposed groups) and absolute risk reduction (actual probability of an outcome regardless of any other factors) for developing Alzheimers disease. There was valuable insights into which vaccines may protect against Alzheimer’s.
People who received at least one influenza vaccine were 40% less likely than their unvaccinated peers to develop Alzheimer’s disease.
Patients who received Tdap/Td vaccine were 30% less likely than their unvaccinated peers to develop Alzheimer’s (7.2% of vaccinated patients vs 10.2% of unvaccinated patients developed the disease). Also Herpes Zoster vaccine, otherwise known as the Shingles vaccine saw a 25% reduction in Alzheimer’s disease. For the pneumococcal vaccine, there was a 27% reduced risk. People who received at least one influenza vaccine were 40% less likely than their unvaccinated peers to develop Alzheimer’s disease. That is a pretty big deal!
So, what’s the reasoning behind this protection? it’s possible that vaccination may reduce an immune system function that attacks amyloid plaque as an invader causing chronic inflammation and destroying healthy nearby cells. Vaccines may also enhance the ability of the immune system to remove amyloid plaque. Of course these vaccines protect against infections like shingles, which can contribute to neuro-inflammation.
There may be a novel vaccine coming soon that can prevent or reduce the impact of Alzheimer’s disease. Preliminary research was presented at the American Heart Association Basic Cardiovascular Sciences Scientific Sessions 2023 this summer. Research was on mice and the vaccine targeted a protein involved in Alzheimer’s disease and helped eliminate toxic cells. After the vaccine, not only did mice have fewer amyloid plaques and less inflammation on brain tissue but it showed improvement in behavior and awareness. Of course more studies need to be done potentially on humans.
Getting vaccinated is still a personal choice and this time of year gets us thinking about protecting ourselves and those around us. There are risks in getting vaccines and risks in not getting vaccines. Now there is also the potential fringe benefit of vaccination, which is reducing the risk of Alzheimer’s.
References: Cimons. Can vaccinations save your brain? Your health, AARP Bulletin October 2023.
Barkley, C. Several vaccines associated with reduced risk of Alzheimer’s disease in adults 65 and older. UTHealth Houston/News August 16, 2023.
American Heart AssociationBasic Cardiovascular Sciences Meeting Report- Abstract P3004. Novel vaccine may hold key to prevent or reduce the impact of Alzheimer’s disease.