Health Happenings

An Alzheimer’s Vaccine?

Today, Alzheimer’s afflicts about 12 million people, 4 million of them Americans. By 2025, more than 22 million people worldwide will have Alzheimer’s disease, unless researchers are able to discover a vaccine.

A group led by Dale Schenk at Elan Pharmaceuticals believes they may have already discovered a vaccine. Schenk and his colleagues are convinced that Alzheimer’s is caused by buildup of a protein called beta amyloid in the brain. Recent tests have shown that a vaccine containing a synthetic version of beta amyloid can produce an immune response that in turn reduces buildup of the protein in the brains of mice genetically engineered to contract a form of Alzheimer’s. While they are enthusiastic about the results, the researchers say success in mice does not guarantee success in humans.

But Schenk has reported encouraging preliminary results in the first safety trial of the potential vaccine. Twenty-five U.S. patients with mild to moderate Alzheimer’s were given a single dose, which appears to be safe and well tolerated. The next trial will involve 75 to 80 patients, who will receive at –least three doses over a period of 6 to 9 months. Future tests should show whether or not the vaccine is able to produce an immune response strong enough to reduce buildup of beta amyloid.

With a vaccine in hand, scientists will be able to develop a technique for accurately predicting who will get the disease. Studies have already identified many of the risk factors. Certain genes make some families vulnerable. Head injuries may increase risk, as may high blood pressure. People with higher levels of education tend to have lower risk. But the greatest risk for Alzheimer’s is age. Cases of the disease double with every five years of age between 65 and 85.