Skin Patch Vaccine for Alzheimer's Shows Promise

People with Alzheimer's disease develop plaques in their brain tissue. Science has developed an injectable vaccine to fight these plaques, but it's proven dangerous to humans. Now a new method of delivering the vaccine is being developed - the skin patch - and it seems much less risky.

How the vaccine works
In the brains of patients with Alzheimer's disease there is an accumulation of a protein called beta amyloid. The vaccine "trains" the body to identify this protein as a foreign substance and destroy it. The theory is that preventing the buildup of beta amyloid protein will in turn help break down plaques and prevent, or at least discourage, development of Alzheimer's symptoms.

A brief history of vaccine development
Scientists had developed a vaccine that appeared to be effective in rats. But when this vaccine, which was administered by injection, was given to human test subjects, some of them developed lethal side effects. The vaccine seemed to produce an autoimmune reaction which led to inflammation of the brain tissue. The testing of this particular vaccine was suspended indefinitely.

However, the study participants who did not react this way to the vaccine have done well. As a result, researchers have been trying to find a way to control the body's response and make it more predictably positive.

The latest research
The most recent testing, done at the University of South Florida, involved a transdermal - skin patch - vaccine. Scientists believe that the skin contains cells that can control the immune reaction so that it's less harmful.

Their initial tests, with mice that had been bred to have Alzheimer's-type symptoms, have shown that the vaccine does reduce the amount of plaque in the brain without any harmful side effects. This physiological response is promising, but now they need to determine whether the vaccine will have an effect on the symptoms - in other words, improve the mice's memories. If that's successful, they may begin cautious testing of the skin patch vaccine in human subjects.

The promise
Besides appearing to be less risky when it comes to autoimmune responses, skin patches have other advantages. One of the biggest, at least with elderly patients, is that they're easy to use. There are no injections to take or even pills to swallow. As a result, a skin patch is more likely to be used, and used properly, which improves its chances of being effective.

There's still a long way to go before a skin patch vaccine will be approved for use and available to people who need it. And certainly, after the problems with the last study, researchers will be even more careful with human testing the next time.

But even if this vaccine doesn't make it to pharmacy shelves, it still shows that there is a way of breaking down plaque in laboratory animals. Hopefully it's just a matter of time before scientists break the "laboratory" barrier and are successful at developing an Alzheimer's treatment that works with humans.