[Jan. 24, 2024: JJ Shavit, The Brighter Side of News]
Vaccines may change how the immune system responds to the build-up of toxic proteins that contribute to Alzheimer's disease. (CREDIT: Creative Commons)
More than 6 million Americans are diagnosed with Alzheimer's disease, and with an aging national population, this number is bound to rise. The search for factors that can impact Alzheimer's disease development has been the focus of many scientific studies. But now, a groundbreaking new investigation led by a team from the McGovern Medical School at UTHealth Houston has brought to light a potentially significant connection between adult vaccinations and reduced risk for Alzheimer's disease.
The Journal of Alzheimer's Disease recently unveiled a pre-press version of this study online. Spearheading the research were co-first authors Kristofer Harris, program manager in the Department of Neurology at UTHealth Houston; Yaobin Ling, graduate research assistant with McWilliams School of Biomedical Informatics; and Avram Bukhbinder, MD, a distinguished alumnus of the medical school.
Lending his expertise as the senior author was Paul E. Schulz, MD, the Rick McCord Professor in Neurology with McGovern Medical School. Readers can anticipate the full research to be available in print on September 12, Volume (95) Issue (2).
These revelations follow just 12 months after another pivotal study by Schulz's team. Their previous research found that people who had received at least one influenza vaccine saw a 40% reduction in Alzheimer's risk compared to those who hadn't.
Digging deeper into this correlation, Schulz said, "We and others hypothesize that the immune system is responsible for causing brain cell dysfunction in Alzheimer's. The findings suggest to us that vaccination is having a more general effect on the immune system that is reducing the risk for developing Alzheimer's."
To determine this, researchers conducted a retrospective cohort study. They studied patients who had no dementia signs in the past two years and were at least 65 at the beginning of an eight-year observation period. By comparing two analogous groups of patients – one vaccinated with Tdap/Td, HZ, or pneumococcal vaccine and the other not – they were able to determine the relative and absolute risk reductions for Alzheimer's.
Emphasizing the significance of the large datasets, Yaobin Ling commented, "It's particularly encouraging to observe consistent results across numerous large-scale health care databases."
Results of a risk regression model on a) Tdap/Td, b) HZ, and c) pneumococcal vaccinations, stratified by three different ages (65, 75, 85) as measured at baseline, on the cumulative incidence function (CIF) of AD. HZ, Herpes zoster; Tdap, Tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis; Td, Tetanus toxoid and reduced diphtheria toxoid. (CREDIT: Journal of Alzheimer's Disease)
Taking advantage of advanced data models and vast databases, Xiaoqian Jiang, PhD, who holds the Christopher Sarofim Family Professorship in Biomedical Informatics and Bioengineering with McWilliams School, said they "gained valuable insights into which vaccines may protect against Alzheimer's."
Remarkably, those vaccinated with the Tdap/Td vaccine were 30% less likely to develop Alzheimer's compared to their non-vaccinated counterparts. HZ and pneumococcal vaccines also showcased promising results, revealing a 25% and 27% reduced Alzheimer's risk, respectively.
Pairwise Correlation of Covariates in the Unmatched Cohort Prior to Use in the Competing-Risk Regression Model for the Secondary Analysis. (CREDIT: Journal of Alzheimer's Disease)
Putting these numbers into perspective, Schulz mentioned that newly introduced anti-amyloid antibodies, used in Alzheimer's treatments, only managed to slow down the disease's progression by 25%, 27%, and 35%.
Bukhbinder proposed a combination of mechanisms that could explain these observations. He stated, "Vaccines may change how the immune system responds to the build-up of toxic proteins that contribute to Alzheimer's disease, such as by enhancing the efficiency of immune cells at clearing the toxic proteins."
Paul E. Schulz, MD, the Rick McCord Professor in Neurology with McGovern Medical School at UTHealth Houston, was senior author of a study that found several vaccinations were linked to a reduced risk of Alzheimer's disease. (CREDIT: UTHealth Houston)
Shedding light on the importance of routine vaccinations, Harris emphasized, "Our findings are a win for both Alzheimer's disease prevention research and for public health in general, as this is one more study demonstrating the value of vaccination."
The research was an amalgamation of efforts from various experts, including Kamal Phelps, MD; Gabriela Cruz; Jenna Thomas; Luyao Chen, MS; Yejin Kim, PhD; and Xiaoqian Jiang, PhD.
As our understanding of Alzheimer's continues to grow, this research offers a fresh perspective. Not only does it underscore the importance of adult vaccinations for general health, but it also provides a promising direction for future Alzheimer's research.
For more science news stories check out our New Innovations section at The Brighter Side of News.
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