The drug will be tested on 96 volunteers in USA and South Africa
South Africa says it has approved the first phase of a human trial to test the safety and side-effects of a prototype Aids - the first trial of an Aids vaccine.
It will specifically target the strain of the disease which is killing millions of people across Africa.
The proposed testing programme, which was approved by South Africa's Medicines Control Council on Wednesday, is expected to involve a total of 96 participants, equally divided between the United States and South Africa.
The head of the trial, Dr Glenda Gray, says the first tests will be carried out on 12 volunteers in the United States, before being undertaken in South Africa.
Breaking the logjam
She says it is the first time that the C-strain of the disease which occurs predominately in southern Africa, will be targeted.
"We are hoping that this vaccine will break the logjam and that others will go through quickly (to the testing phase)", Dr Gray said.
The trials will be conducted in conjunction with the United States where the so-called "alpha-virus replicon vector" technology, the basis for these trials, was developed.
The results of the tests are expected within two years.
It could take years before the vaccine is developed in South Africa
The South African Government has been criticised for not providing Aids patients with anti-retroviral drugs.
In February thousands of demonstrators campaigning for HIV/Aids treatment in South Africa held a protest outside parliament in Cape Town as President Thabo Mbeki was making his annual State of the Nation speech.
The government had said the drugs were too expensive and could be dangerous.
Aids experts have repeatedly cautioned that an effective vaccine against the disease is years away.
The president of the International Aids Vaccine Initiative, Seth Berkley, said on Wednesday that it could be 2009 before an Aids vaccine is developed.
There were many obstacles and few drugs in the pipeline, after the best hope failed in trials earlier this year, he said.