ROME Pioneering work by Italian scientists on a possible AIDS vaccine is reaching a crucial stage with the treatment ready for human testing, the head of the project said.

"Phase one (of human testing) is already in an advanced organizational phase. We hope to start after the summer," Dr. Barbara Ensoli, head of virology at Italy's National Health Institute, told Reuters in an interview.

Ensoli, who worked with Robert Gallo, one of the fathers of AIDS research, said initial testing would be done in Italy's two largest cities, Rome and Milan. Both have high rates of AIDS.

Researchers on the five-year-old project have taken a different approach to tackling HIV, the virus which causes AIDS. They have sought to block the virus from growing in the body rather than bolstering the immune system against it, as more traditional vaccines try to do.

Ensoli, 41, is trying to halt the HIV virus' development through a key building block of the virus, the TAT protein.

This protein, she discovered, is vital for the virus to take root and spread and is released by cells soon after infection.

"By targeting the TAT protein we will be able to control virus replication, to render the infection abortive, to block disease onset in HIV negative subjects," she said.

"For HIV positive subjects, the vaccine will act on the same rationale, blocking virus replication and hopefully avoiding the use of medicines," she said. In preliminary tests on monkeys, she has had a 71 percent success rate.

A Different Approach

More traditional methods have so far focused on trying to manipulate the so-called "envelope protein" on the surface of the HIV virus, in effect trying to teach antibodies how to identify the virus and then fight it.

The traditional vaccine method has worked with many viruses, but it has not been successful against HIV's ability to mutate and revive itself.

HIV has subtypes that can vary between geographical areas, from person to person or even within the same person over time, making any strain-specific approach, such as the "envelope protein", unsuccessful.

Ensoli, who spent 12 years in the United States working as a researcher under Gallo, says her vaccine could prove to work against all strands of the HIV virus.

"We have studied and compared data on infected individuals from Italy, Uganda and South Africa which are infected with different virus strains and all of them recognized (the TAT vaccine) in the same way.

The first stage of human testing, which will assess whether the vaccine is toxic for humans, will last six months, followed by six months to study the data, Ensoli said.

The second phase will probe the reaction of the body's immune system to the treatment and a final stage will test the success rate in both HIV infected cases -- as a therapeutic vaccine -- and in healthy patients as a preventive vaccine.

Ensoli hopes to conduct the last two test stages in South Africa and Uganda. But even if successful, she does not expect any vaccine to be publicly available for five to seven years.

A United Nations report released last November showed that more than 21 million people have died from AIDS since it was identified two decades ago. More than 36 million people are infected with the virus.

Sub-Saharan Africa remains ground zero of the epidemic, with at least 25 million people HIV positive. Experts expect Asia to be the next hotbed of the virus, followed by countries in the former Soviet Union, such as Ukraine.

(Reuter)