South African researchers say they have seen promising results in initial trials of potential AIDS vaccines.
Researcher Dr. Gavin Churchyard told reporters Friday in Johannesburg that preliminary data from field trials showed that one vaccine - HVTN 204 - has had some effect against strains of HIV - the virus that causes AIDS.
Another researcher, Dr. Eftyhia Vardas has been testing a separate vaccine that she says has shown to be effective in keeping down viral loads in AIDS patients. The viral load is the measurement of HIV in the blood.
Churchyard says the results are good news and an important milestone but there is still a long way to go in terms of testing the vaccines.
The researchers are part of the South African AIDS vaccine initiative, a project designed to co-ordinate the research, development and testing of AIDS vaccines.
Recent figures from the United Nation's AIDS agency show that nearly one in five South African adults aged 15 to 49 are infected with HIV.
Some information for this report provided by Reuters.