New vaccine can beat Aids virus defences

A RADICAL approach to developing an Aids vaccine has led to the creation of a successful antidote against the many different strains of the virus.

Scientists believe the results mark a significant breakthrough in the struggle to create a vaccine that works against all the sub-types of HIV known to be circulating.

More than 10 years of research into developing an Aids vaccine have been hampered by the virus's ability to change its outer coating and so evade the antibodies generated by inoculation.

One of the principal difficulties in developing an effective Aids vaccine is identifying a feature of HIV common to all strains of the virus. Scientists believe the latest research may now have done this.

A team of researchers from the University of Montana and New York University Medical Center managed to "freeze" an Aids virus in the act of contorting itself as it invaded a cell, exposing a part of its outer glycoprotein "envelope" of HIV not normally seen.

Having identified this hidden region, the scientists used it to generate a prototype vaccine they injected into mice to generate antibodies that would specifically attack it.

In a series of further experiments, published in the journal Science, they isolated these mouse antibodies and found that they successfully neutralised, or inhibited, 24 out of 25 strains of HIV isolated from patients.

Professor Jack Nunberg, of the University of Montana, said: "Our vaccine is the first which has elicited antibodies which can neutralise any virus from human patients. To see that the response is very broad offers real hope that a broadly effective HIV vaccine might be developed."

Dan Littman, professor of pathology at New York University, said the results are a "very encouraging development" in terms of developing a single vaccine to work against all strains of HIV.

"This is really the first example of being able to somehow trick the immune system into making broadly neutralising antibodies that are presumably active against the HIV envelope glycoprotein," Professor Littman said.