Sustained research programmes will eventually lead scientists to develop a vaccine for the prevention and treatment of HIV, Health Minister Aaron Motsoaledi said.
He was addressing reporters in Johannesburg after the announcement of the discovery of a method to develop antibodies able to kill multiple strains of HIV.
"I think we are a step closer to the day when we will have a viable vaccine. This announcement is welcomed with pride by the department of health as it tells us more about the HIV virus," he said.
"These studies illustrate the importance of research and the need for patience and dedication.
"In 2009, we were worried that research and development were taking a knock, but now we are proud that every year something is announced by our scientists."
Motsoaledi said it was urgent for South Africa to find a cure for HIV.
With a huge burden of infection, the government was closely following all HIV-related research.
"We have got more interest in these developments than anybody else throughout the world. As I speak now, 2.4 million people, which is 30 percent of all people being treated [for HIV] in the whole world, are here in South Africa," he said.
"In the next 24-months, that figure must move to 4.6 million. Anything that moves towards a vaccine interests us more than anybody else. For that reason, we put everything in our arsenal."
National Institute of Communicable Diseases virology head Prof Lynn Morris said the antibodies capable of combating HIV would now be sent for pre-clinical tests.
She said a small number of HIV-infected people naturally developed these antibodies, but were not helped by them because they were unable to kill the wide range of HIV.
"We need to understand how to make better antibodies to HIV. We can learn that from people who are already infected, because a small proportion of them make these broadly neutralising antibodies," she told reporters in Johannesburg.
"There has been a lot of focus on the individuals that make this special type of antibodies. That information, we hope, is going to help us make a better vaccine to HIV."
Large quantities for further testing
A KwaZulu-Natal woman, identified in the research as CAP256, had responded to HIV infection by making the antibodies.
The research team identified the antibodies in her blood, cloned them in a laboratory, then used them to find the pathway followed by CAP256's immune system to make them.
The identification and cloning of the antibodies had enabled researchers to make large quantities for further testing, similar to the way a medicine used to prevent or treat HIV would be tested.
"What we have to do now is to design a vaccine that is able to engage with the rare B-cells. If we are able to do that, we should be able to make a vaccine that will take months for people to develop the immunity against HIV," said Morris.
Sometimes referred to as the body's army, antibodies are specialised cells produced by B-cells as a primary immune defence. They are used by the body for either treatment or prevention.
Trials in monkeys
Morris said CAP256's antibodies would be used in a sequence of pre-clinical trials in monkeys, a process which could take years to prove their efficacy.
If successful, the research would guide HIV vaccine development. The antibodies might also be used as treatment for HIV.
The research was primarily funded by the US vaccine research centre, and the science and technology department.
The scientists worked in the "Caprisa" consortium of Aids researchers, which includes the University of KwaZulu-Natal, the University of the Witwatersrand, the National Institute of Communicable Diseases, the University of Cape Town, and Columbia University in the US.
Science and Technology Minister Derek Hanekom said the project could make significant strides in the global quest for an HIV vaccine.
"The knowledge that has been generated and the discoveries made are, at the very least, of huge significance and could make an enormous difference in the search for an effective vaccine," he said.