A single injection of a type of virus known as adenoviruses can help give up the habit of drinking, a study says.

Researchers have found that rats bred to crave alcohol were found to drink 50% less for more than a month after being injected with engineered adenoviruses.

Many people in East Asia react badly to alcohol because of mutations in the gene for aldehyde dehydrogenase. But these mutations also reduce the risk of succumbing to alcoholism by two-thirds or more.

Aldehyde dehydrogenase is blocked by the drug disulfiram, which is sometimes used to help alcoholics quit the habit, said New Scientist.

To provide a longer-lasting effect, scientists engineered adenoviruses to carry an "antisense" version of the aldehyde dehydrogenase gene that blocks the production of enzyme involved in alcohol metabolism.

A single injection reduced the enzyme's activity in rats' livers by 80%, said researcher Amalia Sapag of the University of Chile in Santiago.