Vaccinations have become part of life for most people, revolutionising our resistance to diseases and, in some cases, virtually eradicating diseases.
Now, certain vaccinations have been linked to a reduced risk of developing Alzheimer’s disease.
The hunt for medications – or even lifestyle changes – to stop or slow the development of Alzheimer’s has been occupying countless research labs for decades. And the need is becoming more urgent because ageing populations are living longer, mostly healthier, lives.
A study conducted by the University of Texas Health Science Center at Houston was recently published online in the Journal of Alzheimer’s Disease. It built on a previous study by the team, which found that people who received at least one influenza vaccine were 40 per cent less likely than their unvaccinated peers to develop Alzheimer’s disease.
Professor Paul Schulz, director of the Neurocognitive Disorders Center at McGovern Medical School, said the team had started wondering whether that finding was specific to the flu vaccine.
Several adult vaccines tested
It found that several additional adult vaccines were also associated with a reduction in the risk of Alzheimer’s.
“We and others hypothesise that the immune system is responsible for causing brain cell dysfunction in Alzheimer’s,” he said. “The findings suggest to us that vaccination is having a more general effect on the immune system and that is reducing the risk for developing Alzheimer’s.”
Getting vaccinated against shingles, pneumonia and other illnesses – in addition to influenza – were also found to reduce the risk of Alzheimer’s.
The team found that those who received shingles and pneumonia vaccines — along with tetanus and diphtheria — had as much as a 30 per cent reduced risk of developing Alzheimer’s.
Those who received the vaccine for tetanus, diphtheria and pertussis were 30 per cent less likely to get Alzheimer’s.
Patients who received the pneumococcal vaccine, which protects against the bacteria that can lead to pneumonia, meningitis and sepsis, demonstrated a 27 per cent lower chance of an Alzheimer’s diagnosis.
The shingles vaccine was linked to a 25 per cent reduced risk.
The eight-year study involved people who were at least 65 at the start and who had not been diagnosed with dementia in the previous two years. It compared groups of vaccinated and unvaccinated people for each of the vaccines, looking at the occurrence of Alzheimer’s diagnoses.
Dr Brett Osborn, a neurosurgeon in Florida who also runs an anti-ageing facility, reviewed the findings.
He said: “This must be studied carefully, but there is a growing body of evidence that regular vaccines are associated with decreased Alzheimer’s risk.
“This effect is likely the result of a heightened immune response to amyloid plaques or their upstream precursors.
“In essence, immune system surveillance – toward amyloid – has improved, potentially as a result of the vaccine, thereby improving amyloid clearance from the brain.
“This improved scavenging would directly limit amyloid build-up and potentially slow the onset of the disease.”
Why our immune systems weaken
Dr Osborn says that as we age, our immune systems weaken, making us more susceptible to cancers and infections.
“In this case, these vaccines, despite their non-specificity for amyloid plaques, are altering the state of our immune system, giving it a much-welcomed boost.”
Dr Marc Siegel, a professor of medicine at NYU Langone Medical Center, said the study showed an association but did not prove that the vaccines reduced risk.
“I believe this is due to ‘priming the pump’, meaning that a healthy immune system that is already alert for viruses due to the vaccines we take can also target neuro-inflammation and abnormal proteins that lead to Alzheimer’s,” he said.
Co-first author Kristofer Harris said the research highlighted how important it is for patients to have ready access to routine adult vaccinations.
“Over the last couple of years, the field of Alzheimer’s disease has vastly expanded, especially with the recent approval of anti-amyloid antibody medications by the FDA [US Food and Drug Administration]. 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 Alzheimer’s disease prevention research and for public health in general, as this is one more study demonstrating the value of vaccination.”
Do you routinely have the vaccinations referred to in this study? Are you hopeful there will be further developments in the bid to reduce the risk of Alzheimer’s? Share your thoughts in the comments section below.
Also read: Breakthrough cancer blood test developed in Australia