AIDS researchers would like to expand their study to span the globe, including a rare group of HIV-infected people, whose immune systems prevent the virus from thriving in their bodies.

So far, studies of these 'elite controllers' aiming to find an AIDS vaccine have been confined to north America, however, scientists would now also like to rope in people from Asia, Africa and Latin America.

These elite controllers are not only health; they show no signs or symptoms of HIV-related disease and do not require any treatment, sometimes for 10 years after becoming infected. Scientists would like to discover the secret behind their robust immune systems and use the information to design a vaccine for others who are not so lucky.

Most of these 2,000 controllers or 'long term non-progressers' are from the United States and Canada, but now scientists would also like to bring in others from China, South Africa, Peru, Thailand, Brazil and other parts of the world, to study their blood samples and other data closely.

An estimated 33-million people worldwide suffer from HIV, for which no cure has been found, so far. While, drugs have the capability of controlling the virus, people who can do it naturally, are unusual.

China seems to have many of these 'elite controllers' and has about 400-villagers who are still surviving after they were infected in the 1990s, including having very low viral loads.

There are two classes of controllers, the more common of them have 2,000-copies of the virus or fewer in their bodies, and the even rarer elite controllers have fewer than 50-copies. On average, an HIV-infected person has 30,000 copies.

Regular equipment cannot detect the virus in these elite controllers, who appear to have superior dendritic cells, one of the many types of immune cells that seem to be the access point for the AIDS virus.

These dendritic cells have higher activity of certain receptors i. e. molecular doorways in cells, offering a potential opportunity for the manipulation of these two receptors to advance vaccine studies.

The CD8 T-cells i. e. another type of immune cell these controllers have also seems to have unusually powerful responses to the HIV virus.