Scientists are moving closer to developing a vaccine for treating Alzheimer's disease.health and fitness Updated: Mar 08, 2004 17:52 IST
Scientists are moving closer to developing a vaccine for treating Alzheimer's disease. A study published in this month's issue of the journal Alzheimer's Disease and Associated Disorders, describes a promising new primate model for testing the vaccine which may enable scientists to study it in an animal model of Alzheimer's that is very similar to humans. The goal is to discover the cause of serious side effects that halted an earlier study of the vaccine in people, according to the Alzheimer's Association.
According to William Thies, Ph.D., Alzheimer's Association vice president for medical and scientific affairs , "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."
"Tremendous progress has been made by the National Institute on Aging, the Alzheimer's Disease Centers, universities, pharmaceutical companies and the Alzheimer's Association in understanding Alzheimer's disease. The Association's goal of delaying the disabling symptoms and eventually preventing Alzheimer's appears to be a feasible objective that the research community can achieve in the next decade," Thies added.
According to Sam Gandy, the lead author of the study titled "Alzheimer A_ Vaccination of Rhesus Monkeys (Macaca Mulatta)," "This may prove to be a helpful model system for us to discover why some humans develop brain inflammation when they are vaccinated with beta amyloid," He believes the study was initiated to determine whether the brain changes associated with vaccination of humans could be modeled in aged nonhuman primates.
"These monkeys respond to the vaccination by producing lots of antibodies to Alzheimer amyloid and by showing elevated plasma amyloid that is presumably on the way being cleared from the body. We also examined the brains after six months of vaccination. There was no evidence of inflammation," Gandy added.
In this proof-of-concept study, Gandy and colleagues vaccinated two rhesus monkeys with beta amyloid, a protein fragment considered a prime suspect in disrupting and destroying nerve cells in the Alzheimer brain. The vaccinated monkeys developed significant levels of antibodies to beta amyloid as well as high levels of beta amyloid circulating in their blood, much of it attached to antibodies.
Two other monkeys were vaccinated with a "control" amyloid: in this case, the islet amyloid that builds up in diabetes.But they did not develop antibodies against beta-amyloid and had much lower circulating beta-amyloid levels. None of the four monkeys showed any evidence of brain inflammation. The study was funded by The National Institute of Neurological Diseases and Stroke.