The Italian-made prototype of the AIDS vaccine is being administered to volunteers in Rome and Milan, a scientist working on the research team said.

This first-stage of testing is intended to establish whether the vaccine, developed by a team headed by virologist Barbara Ensoli, is harmless, a member of the team, Valeria Fiorelli, told AFP.

She did not say how many subjects were participating in the test nor what their state of health was.

Fiorelli said "recruitment (of test subjects) began in November 2003 and is still ongoing".

The Italian daily Corriere della Sera reported in its Tuesday edition that the research team was having trouble finding enough test subjects, and that the scientists wanted at least 32 volunteers who were not infected with the virus and 53 people who were HIV-positive.

HIV is the virus that leads to full-blown AIDS. An estimated 40 million people are infected with HIV/AIDS worldwide, with about 26.6 million of them in sub-Saharan Africa, according to the latest UN estimates.

The Corriere della Sera also said the first phase of human testing was due to run until the end of the year.

AIDS researchers in several countries are working trying to develop a vaccine, but with no success so far.

The Italian vaccine, unlike other versions, focuses on the use of a protein which regulates the reproduction of the HIV-1 virus within the human. Other vaccines have targeted the outer layer of the virus itself.

"Experimental studies on animals have shown that the administration of this Tat protein has no toxic effect and induces a complete immune response capable of blocking the replication of the virus and, as a result, the development of the disease," the ISS said in a statement.

TERRA.WIRE