London: Scientists, including an Indian -origin researcher, claim that a vaccine against heart attack is being developed, which could be available in the market within five years.

Coronary heart disease occurs when fatty plaques build up in the blood vessels feeding the heart and over time become narrowed. Parts of the plaque may break off causing a clot to form which can block the artery causing a heart attack.

Now, a team, led by Prof Prediman Shah from Cedars-Sinai Heart Institute in US and Prof Nilsson from Lund University in Sweden, says experiments have shown it is possible to alter the way the immune system reacts to plaques in the arteries to reduce inflammation and the severity of the build-up.

In fact, the scientists say that injections of antibodies could help prevent the build up of fat in the arteries which cause narrowings and break off leading to heart attacks, 'The Daily Telegraph' reported.

The team has already formulated a vaccine that reduced plaque build up by 60 to 70 per cent in mice. The resulting CVX-210 vaccine, currently in development as an injection by CardioVax, is waiting regulatory clearance to start clinical trials, say the scientists.

A second vaccine using the same materials has been formulated as a nasal spray, Prof Nilsson said.

Moreover, another approach, of directly injecting antibodies against bad low density lipoprotein which carries cholesterol in the blood and forms the basis of the plaque, is already in trials.

Prof Nilsson said: "The rationale is that since oxidized LDL plays a major role in the development of atherosclerotic plaques and harmful inflammatory processes, directly targeting oxidised LDL should prevent plaque formation and reduce inflammation."

Early studies showed that the antibody, BI-204, developed jointly by BioInvent and Genentech, reduced plaques by half and was well tolerated when tested in 80 healthy people.

A trial of BI-204 in 144 people with heart disease is underway in America and Canada where body scans will measure plaques in the arteries over time, say the scientists.

Prof Nilsson said it was unlikely that the products would be given as traditional vaccines in early childhood and instead were more like drugs in that they would need to be given repeatedly.

He said: "Both these treatments are far more like drugs -- to be effective they'd need to be given long term. The antibody therapy in particularly is likely to be expensive so you could probably only afford to give it to high risk populations rather than everyone."

Prof Peter Weissberg, Medical Director at the British Heart Foundation added: "A vaccination approach to treatment of atherosclerosis is based on an attempt to interfere with the cellular mechanisms that cause life threatening build up of fatty deposits.

"There will be great interest in the outcome of the on-going studies to see firstly if this approach is safe and secondly, whether it can influence the progression of vascular disease in the long term."