Arm Yourself Against Alzheimer’s
HOPE IN THE BCG VACCINE.
A century-old vaccine for a once-prevalent disease now shows promise as a new application for a growing health threat in the 21st century. When the Bacillus Calmette-Guérin vaccine was developed in France in the 1920s, it was a breakthrough in the fight against tuberculosis (TB).
New research shows this vaccine may be able to help ward off Alzheimer’s disease (AD), the cases of which are expected to skyrocket over the coming decades.
Bacillus Calmette-Guérin (BCG) was named after the Parisian scientists who developed it, Albert Calmette and Camille Guérin. TB, or consumption as it was called in those days, was the leading cause of death in Europe in the 1800s.
BCG proved to be a lifesaver. Its arrival, along with a variety of improvements in treatments and public health, meant TB became far less of a threat in developed countries, so much so that the vaccine is no longer widely administered in Canada or the U.S.
Recent research has given BCG new relevance, with findings that show it could be effective against an array of conditions, including diabetes, multiple sclerosis, and even AD.
“The benefits of this drug just keep coming out in randomized trials around the world for all these disease indications,” Dr. Denise Faustman, an immunologist and associate professor at Harvard Medical Schol, said in an interview with Mind Over Matter®.
“So, all of us who work on this globally are just driven to try to get these benefits to the public,” she added.
Dr. Faustman is part of an international BCG working group that meets about every 18 months to talk about ways to encourage more researchers to explore the vaccine’s potential.
THE AD CONNECTION
The AD angle emerged through studies of people with bladder cancer, for which BCG has become a common treatment. In 2019, researchers at Hadassah-Hebrew University Medical Centre in Jerusalem published the results of a study in PLoS One of 1,371 bladder cancer patients, some of whom received BCG and some of whom did not. The researchers concluded:
“Bladder cancer patients treated with BCG were significantly less likely to develop AD at any age than patients who were not so treated. This finding of a retrospective study suggests that BCG treatment might also reduce the incidence of AD in the general population.”
Those findings were backed up by an even larger American study published in 2023 in Jama Network Open that looked at 6,467 bladder cancer patients over a period of 34 years. It found a “significantly lower rate and risk of ADRD (Alzheimer’s disease and related dementias)” among people treated with BCG.
Two 2024 papers explored the reasons why BCG is having this effect and suggested it deserves closer consideration as a possible vaccine against AD. They concluded that it all has to do with boosting the immune system.
“The basic idea comes from the notion that microbial infection might be involved in the etiology (cause) of Alzheimer’s disease,”
explained Professor Richard Lathe, a molecular biologist at Edinburgh University, who co-authored the papers with Professor Charles Greenblatt of Hebrew University.
He also told Mind Over Matter® that the concept is supported by several lines of evidence. He noted that microbes are detected in the AD brain at much higher levels than normal. The immune system tends to decline as we age, leading to a variety of conditions associated with microbial proliferation.
While the amyloid-β (Aβ) peptide is often found in the brains of people with AD, there is research indicating that Aβ is not causing the disease but is rather a defence mechanism against microbes.
The BCG vaccine protects against tuberculosis by introducing into the body a weak version of the bacteria that causes TB and, in the process, strengthens the immune system.
Professor Lathe credits his co-author with making the link between the vaccine and AD: “The original discovery went back to Chuck Greenblatt, who argued that if Alzheimer’s is caused by infections, and if BCG is effective by stimulating the immune system, then we ought to see a decline in rates of AD.”
They surveyed five different studies and found that, on average, bladder cancer patients who were treated with BCG had approximately 45% fewer cases of Alzheimer’s than those of a similar age who did not receive the vaccine. The conclusion was that “it could represent a sea-change in how we manage patients with mild cognitive impairment through to dementia.”
Professor Lathe said that much larger clinical trials are needed to confirm the findings, but some scientists are already convinced.
“What’s intriguing is that many professionals in the field openly admit to having been BCG-vaccinated. I’ve been BCG vaccinated. So, a lot of professionals actually believe this,” he said.
“It’s probably worth it (to get the vaccine), even if you’ve got Alzheimer’s disease, because you can tip the balance.”
A SPECTRUM OF IMPACT
There are multiple research projects that have been already done or are underway to determine BCG’s effectiveness against a broad range of diseases and conditions.
A study published in BMJ of newborns in the tiny African nation of Guinea-Bissau found a 38% decrease in all forms of neonatal mortality among babies who were vaccinated with BCG. That project inspired scientists at the University of British Columbia (UBC) to investigate further, and their research indicated a dramatic and rapid impact.
Within three days of administration, the vaccine could reduce mortality from sepsis among newborns. The study found that BCG stimulated the production of neutrophils, which are a type of white blood cell that helps the immune system fight infections.
“The evidence seems to be telling us that BCG is extremely good at training the innate immune system,” said Dr. Nelly Amenyogbe, who was part of the UBC research team. The vaccine is already administered to newborns in many developing nations, but often only reaches half of the babies, due to supply issues. She told Mind Over Matter® that the findings should encourage public health officials to improve their vaccination rates.
Now a post-doctoral fellow at Dalhousie University, Dr. Amenyogbe is exploring BCG further and believes the vaccine merits a much wider study.
“We need to understand what it is about BCG that makes it so special in this regard, but also use that knowledge to understand how a well-trained immune system might be the common denominator to prevent many different things that we’re suffering with today.”
The evidence is mounting on several fronts. Scientists at McGill University concluded that it had an impact against the most common strain of influenza. And Dr. Faustman at Harvard is working on a project involving children with Type 1 diabetes.
“It’s a fun topic, because this is what academics should be doing – repurposing drugs that are known to be safe, that have huge health benefits and maybe durable, lasting effects.”
Dr. Faustman said that the challenge now is to get the funding to support the kinds of large-scale trials that can confirm the findings and then prod regulators to allow widespread vaccination programs.
“Alzheimer’s is obviously a disease that affects large populations,” she noted. “It’s disabling and costly. And our limitation right now is we need money to support trials with a safe, generic drug, and that’s what will move these projects forward.”
Source: Mind Over Matter V19