London, Jan 10 (Agencies): Chilean researchers are developing a vaccine that will give the alcoholics a terrible hangover to help them quit liquor.

The vaccine at present is undergoing animal trials. It would increase nausea, accelerate heartbeats, induce sweating and a general feeling of unease. Researchers have already successfully tested the vaccine on rats that were dependent on alcohol and got them to halve their consumption.

They will conduct further animal tests this year before launching human trials in 2012, said Juan Asenio of Chile's Faculty of Sciences and Mathematics. Asenio, who leads the research, said they hoped the jab would reduce alcohol consumption in humans by 90 to 95 percent.

He said the jab works by neutralising a group of enzymes that help the body to break down alcohol. This group, known as aldehyde dehydrogenase, helps the body to build up a tolerance to heavy night outs. About 20 percent of the Asian population lacks this enzyme and thus experience "such a strong reaction that it discourages consumption", said Asenio.

He added that the jab would specifically target liver cells and avoid having a knock-on effect on other cells. It comes just a day after US researchers revealed they had developed a vaccine that could help cocaine addicts to give up their costly habit.