Health

Why an Alzheimer’s Vaccine Likely Won’t Be Approved Anytime Soon

Ignore those headlines that promise a vaccine for Alzheimer’s disease in the near future.

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New research studied a vaccine that was effective in mice, not people. Getty Images

Close to 6 million Americans currently suffer from Alzheimer’s disease — an irreversible brain condition that causes memory loss and cognitive impairments.

As the amount of older Americans increases over the next few decades, the number of Alzheimer’s cases is expected to skyrocket.

The Alzheimer’s Association estimates that by 2050 nearly 14 million Americans will be living with Alzheimer’s.

As of now, there is no cure for the condition or treatment option to reverse the cognitive impairments caused by Alzheimer’s disease.

This may be why early research into a potential vaccine got so much media attention earlier this week. Researchers from the University of New Mexico are working on developing a vaccine that could potentially prevent Alzheimer’s disease.

The vaccine, which was recently tested on mice, helped eliminate the protein tangles in the brain that may cause Alzheimer’s disease, according to a new study published in the journalNPJ Vaccinesearly June.

While these findings do offer hope, it’s far too soon to know if and how the vaccine will work on humans.

After all, mice are a little different from people.

According to health experts, it will be years, maybe even decades, before we have a vaccine ready for humans.

And that’s if the vaccine actually works.

In the past, numerous drug candidates to treat Alzheimer’s disease looked promising in early research only to be found ineffective in widespread testing.

“Although this research is promising, it is too early to get excited. Any human benefit from this vaccine is many years away at best,” Dr. Alex Mroszczyk-McDonald, a family physician with Kaiser Permanente Fontana Medical Center, told Healthline.

There are multiple steps and challenges to getting a vaccine approved and it often takes decades to ensure it’s safe and effective, he added.

Currently, there is no drug to cure or slow down Alzheimer’s disease, although there are a few that treat its symptoms.

The vaccine candidate was designed to target a specific type of protein — known as pathological tau — that’s found in large amounts in the brains of people who have Alzheimer’s disease.

Although tau is present in everyone’s brains, the protein builds up in the brains of people with Alzheimer’s and is believed to cause cognitive decline.

“Tau protein is present in normal and healthy brain cells, but in Alzheimer’s disease the protein accumulates abnormally in ‘tangles’ that interfere with brain signaling and communication,” explains Dr. Verna R. Porter, a neurologist and the director of the Alzheimer’s disease program at Providence Saint John’s Health Center.

The research team found that when the vaccine was administered to the mice, their bodies developed antibodies that removed the abnormal tau protein from the part of the brain associated with learning and memory.

The mice were then put to the test in several maze-like puzzle. The rodents that received the vaccine performed significantly better than those that did not get the vaccine.

The improvements lasted for months, the researchers reported.

Although the vaccine worked very well in the mice, again it’s important to remember that success in a mouse trial doesn’t mean it will help humans.

“In Alzheimer’s drug development, what we see in an animal is interesting, but we know that it cannot necessarily be reproduced in humans,” Dr. Marwan Sabbagh, the director of Cleveland Clinic Lou Ruvo Center for Brain Health, said.

According to Porter, the exact underlying pathology of Alzheimer’s disease remains controversial.

Some scientists believe a buildup of the tau protein is to blame, while others think another mechanism — such as inflammation — is at play.

“Despite the considerable progress being made, a complete understanding of the pathology of this disease has yet to be elucidated,” Porter said.

Health experts agree that much more research is needed to better understand the disease in order to develop a safe, effective treatment.

If the tau protein is, in fact, the cause of Alzheimer’s disease, scientists will also need to figure out how to get this vaccine to people before significant cognitive deterioration occurs that could very well be irreversible.

Scientists are currently working on identifying early diagnostic biomarkers of the disease as well, Porter explained.

“It is believed that Alzheimer’s disease is a far more multifaceted disease than was first supposed. This makes the development of an effective vaccine in humans more complex,” Porter said.

This isn’t the first vaccine for Alzheimer’s that’s been developed.

In fact, many scientists have tried to create vaccines that specifically target tau tangles in recent years, according to Dr. Peter Davies, the director of the Litwin-Zucker Center for Alzheimer’s Disease and Memory Disorders at the Feinstein Institutes and member of the Alzheimer’s Foundation of America’s Medical, Scientific and Memory Screening Advisory Board.

Two of the vaccines are in the early stages of clinical trials in humans.

Others had to be called off because they caused dangerous side effects, such as brain swelling, in patients.

“Many people feel that in this field, active vaccines might just be too risky, and that giving people antibodies instead of trying to persuade them to make antibodies is a lot safer,” Davies said.

It’ll be years before we have a vaccine for humans

The research team from the University of New Mexico plans to secure funding in order to create a vaccine that can be tested and hopefully used therapeutically in humans.

The process can cost millions of dollars and take decades, according to the University of New Mexico.

Still, any new drug development is exciting, says Sabbagh, and the results from the study indicate that the vaccine is absolutely worth exploring.

Researchers from the University of New Mexico are working on developing a vaccine to prevent Alzheimer’s disease. While the vaccine successfully improved symptoms in mice, it’s far too soon to tell if and how the treatment will help humans.


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