A new study at UTHealth Houston in the US has found that several routine vaccinations are linked to a significant reduced risk of Alzheimer’s disease (AD).
Prior vaccination against tetanus and diphtheria, with or without pertussis (Tdap/Td); herpes zoster (HZ), better known as shingles; and pneumococcus are all associated with a reduced risk for developing AD.
Paul Schulz, the Rick McCord Professor in Neurology with McGovern Medical School at UTHealth Houston, was senior author of the study. In 2022, Schulz’s team also found that people who received at least one influenza vaccine were 40% less likely than their unvaccinated peers to develop AD.
Schulz commented: “We and others hypothesise that the immune system is responsible for causing brain cell dysfunction in AD. The findings suggest to us that vaccination is having a more general effect on the immune system that is reducing the risk for developing AD.”
Patients who received the Tdap/Td vaccine were 30% less likely than their unvaccinated peers to develop AD. HZ vaccination was associated with a 25% reduced risk of developing AD. For the pneumococcal vaccine, there was an associated 27% reduced risk of developing the disease.
For comparison, Schulz said, three new anti-amyloid antibodies used to treat AD have shown they slow disease progression by 25%, 27%, and 35%.
Enhancing the efficiency of immune cells
“We hypothesise that the reduced risk of AD associated with vaccines is likely due to a combination of mechanisms,” another researcher Avram Bukhbinder said. “Vaccines may change how the immune system responds to the build-up of toxic proteins that contribute to AD, such as by enhancing the efficiency of immune cells at clearing the toxic proteins or by ‘honing’ the immune response to these proteins so that ‘collateral damage’ to nearby healthy brain cells is decreased. Of course, these vaccines protect against infections like shingles, which can contribute to neuroinflammation.”
Bukhbinder said the research provides unique insights on the possible impact of certain vaccine technologies in the protection against AD.
“This research highlights how important it is for patients to have ready access to routine adult vaccinations,” said Kristofer Harris, Program Manager in the Department of Neurology with McGovern Medical School at UTHealth Houston. “Over the last couple of years, the field of AD has vastly expanded, especially with the recent approval of anti-amyloid antibody medications by the FDA. However, those medications require costly infrastructure in order to be administered safely.
“Conversely, adult vaccinations are widely available and are already routinely administered as part of a vaccination schedule. Our findings are a win for both AD prevention research and for public health in general, as this is one more study demonstrating the value of vaccination.”
Edited by Diana Spencer, Senior Digital Content Editor, Drug Discovery World