German scientists have discovered a substance known as a peptide that thwarts the AIDS virus and causes far fewer side-effects than existing anti-HIV drugs, they said on Wednesday. The breakthrough was reported in the science journal Science Translational Medicine after it had been tested on 18
AIDS patients.

But the scientists at Hanover university hospital or MHH in northern Germany said they have yet to find a way to put the substance, VIR-576, in a pill. All the test patients received it as an intravenous drip.

Variants of the new therapy could also be devised to fight measles, hepatitis C and Ebola disease, they said.

VIR-576 is a protein that smothers human immunodeficiency virus, stopping it docking with cells in the human body.

"It is a completely new therapy approach which we hope will reduce side effects," said Reinhold E Schmidt of MHH. Other existing medicines offered since the mid-1990s work by proofing cells of the body against the virus.

"Our peptide works on the virus, not on the cells, so some of the side-effects won't happen at all," he said.

Current anti-AIDS medications ensure an almost normal life span for HIV-infected people but raise the risk of strokes and liver damage. VIR-576 caused some diarrhoea, but no other major side effects, the tests suggested.

Schmidt cautioned that it could take years before VIR-576 was available from pharmacies as a medicine.