Alzheimer's Vaccine Inching Toward Reality
Despite Setback, Vaccine for Alzheimer's Disease May One Day Be a Treatment Option
WebMD News Archive
May 9, 2005 -- A to
fight against the plaque-building protein implicated in may still be a viable option in the future for treating --
or perhaps even preventing -- the devastating disease, according to new
An earlier study of the experimental Alzheimer's vaccine was halted due to
safety concerns in 2002 after 6% of the participants developed brain
But two new studies that followed the participants suggest that the approach
may slow the memory loss associated with Alzheimer's disease by reducing the
buildup of beta-amyloid plaques in the brain.
"The idea of inducing the immune system to view beta-amyloid as a
foreign protein, and to attack it, holds great promise," says researcher
Sid Gilman, MD, a neurologist at the University of Michigan Health System, in a
news release. "We now need to see whether we can create an immune response
safely and in a way that slows the progression of Alzheimer's disease and
Round 2 for Alzheimer's Vaccine
Although the safety phase of the study of the vaccine was halted in 2002,
researchers continued to follow the participants, and their findings appear in
two studies published in this month's issue of Neurology.
About 300 men and women with mild to moderate Alzheimer's disease received
one to three injections of the vaccine before the study was stopped, and 72
received a placebo.
Brain scans using magnetic resonance imaging (MRI) to measure changes in
brain volume were performed at the start of the study and again after 12 months
or after early termination.
Researchers found that of those who received the vaccine, about 20%
developed antibodies to beta-amyloid protein; that indicates the immune system
of the participants had launched an attack against the plaque-causing protein
in the injected vaccine. All but two of these 59 "immune responders"
had received two doses of the vaccine.
These immune responders also experienced a decrease in brain volume,
according to MRI scans. Researchers say this decrease may reflect a reduction
in plaque buildup, but more study is needed to confirm this effect.