Research into a vaccine for Alzheimer's disease, which was stopped early on safety grounds, is to be resurrected.
It was designed to reverse the disease's progression by clearing the beta amyloid protein that causes the disease.
But the trial was halted in 2002 when 6% of patients in the second phase of the study developed brain inflammation.
Southampton University researchers are to reassess 80 patients who took part in the initial phase of the study.
They will look at whether features of the disease such as memory loss have been halted or reversed.
The vaccine, known as AN-1792, contains a synthetic form of beta amyloid protein.
It acts by stimulating an immune response to the protein.
Preliminary results from the trial showed the vaccine did clear the amyloid protein from the brain.
Vaccine 'realistic prospect'
James Nicoll, professor of neuropathology at Southampton University Hospitals NHS Trust, who is leading the research, said: "This study offers us a unique insight into whether immunisation against Alzheimer's is an effective solution to this devastating disease.
"We know that vaccination can reverse the processes of Alzheimer's to some degree - our challenge is to understand these processes better and translate them into real benefits for patients."
Rebecca Wood, Chief Executive of the Alzheimer's Research Trust, said: "The prospect of a vaccine to protect against Alzheimer's is a realistic one because it is a disease, and not a normal part of ageing.
"Immunisation is an exciting area and we are delighted to be funding this groundbreaking study."
Clive Ballard, director of research at the Alzheimer's Society, said: "There are 25 million people worldwide with Alzheimer's disease and 100 000 people are diagnosed in the UK each year.
"This clearly highlights the urgent need to develop new ways of defeating dementia.
"The vaccine is one of the most exciting treatments for Alzheimer's and we are very please to see ongoing funding in the UK as part of a international effort to develop a vaccine for Alzheimer's disease."