FRIDAY, March 5, 2004 (HealthDayNews) -- Tests on monkeys show promise for an experimental Alzheimer's disease vaccine, says a study in the March issue of Alzheimer Disease and Associated Disorders.
The vaccine was created by researchers at the Farber Institute for Neurosciences at Thomas Jefferson University in Philadelphia.
They injected the monkeys with beta-amyloid. It's a sticky protein substance that accumulates in the brains of people with Alzheimer's. Beta-amyloid is believed to play a major role in the destruction of nerve cells and in the cognitive and behavioral problems associated with the disease.
The vaccinated monkeys developed high levels of antibodies to beta-amyloid. Circulating amyloid levels in the monkeys increased five-fold to ten-fold. Nearly all of that circulating amyloid was bound to antibodies and cleared out of the monkeys' bodies.
"The amyloid in the brain seemed to be bound up to antibodies in the blood and cleared away," study leader Dr. Sam Gandy, a professor of neurology, biochemistry and molecular pharmacology, says in a prepared statement.
"Vaccinating with amyloid brings an immune response that stimulates removal of amyloid from the body," says Gandy, who is also vice chairman of the National Medical and Scientific Advisory Council of the Alzheimer's Association.
William Thies, vice president for medical and scientific affairs for Alzheimer's Association, says in a statement, "The animal model described in this study expands the way we might evaluate new vaccine products.
"Vaccination against amyloid is a reasonable strategy for preventing and possibly treating Alzheimer's, and this study brings us one step closer. Having more model systems that are closer to humans increases the likelihood that we can avoid the kind of side effects that we saw in the first human trial," Thies says.
An earlier study of Alzheimer's vaccine in humans had to be halted because of serious side effects.
More information
The U.S. National Institute on Aging has more about Alzheimer's disease.
