New study reveals a major link between vaccines and Alzheimer’s

More than 6 million Americans are diagnosed with Alzheimer's disease, a number expected to climb as the population ages. Scientists continue searching for factors that influence the disease’s development, hoping to uncover new ways to reduce risk and improve prevention strategies.

A groundbreaking study from the McGovern Medical School at UTHealth Houston has revealed a potentially significant link between adult vaccinations and a reduced risk of developing Alzheimer's disease. The research sheds new light on how certain vaccines may contribute to brain health and longevity.

The findings were recently published online in the Journal of Alzheimer's Disease. The study was led by Kristofer Harris, a program manager in the Department of Neurology at UTHealth Houston; Yaobin Ling, a graduate research assistant with the McWilliams School of Biomedical Informatics; and Avram Bukhbinder, MD, a distinguished alumnus of the medical school.

Paul E. Schulz, MD, the Rick McCord Professor in Neurology at McGovern Medical School, served as the senior author. Schulz has been at the forefront of Alzheimer's research, particularly in exploring the connections between immunization and cognitive health.

This new research follows closely on the heels of another key study by Schulz’s team. Just a year ago, they reported that individuals who had received at least one flu vaccine experienced a 40% lower risk of developing Alzheimer’s compared to those who had never been vaccinated.

The study adds to a growing body of evidence suggesting that vaccinations may play a protective role against neurodegenerative diseases. While the exact mechanisms remain under investigation, researchers speculate that vaccines could help by reducing systemic inflammation or preventing infections that may accelerate cognitive decline.

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."

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.

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."

Tdap stands for Tetanus, Diphtheria, and Pertussis. This vaccine protects against three diseases:

Td stands for Tetanus and Diphtheria. This booster vaccine is used to maintain immunity against these two diseases.

For Adolescents and Adults: Tdap is recommended for preteens around 11-12 years old, but it’s also important for adults who didn’t receive it as adolescents, especially pregnant women during each pregnancy to protect the newborn from pertussis.

Pregnant Women: Getting Tdap during pregnancy helps protect newborns from whooping cough, which can be severe or fatal in young infants.

Booster Shots: Td is given as a booster every 10 years to maintain immunity against tetanus and diphtheria. It's also administered after a severe wound or burn if the last dose was received more than five years ago.

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.

Note: Materials provided above by the The Brighter Side of News. Content may be edited for style and length.

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