Scientists will know in May if they can test it on 7000 people, said investigator Professor Glenda Gray, president of the SA Medical Research Council.
The vaccine – the only one shown to be reasonably effective against HIV after 30 years of research – is being tested on 100 people in this country. It is designed to activate the immune system to fight the virus.
The results of the test will be known in May. If the vaccine proves to be effective, regulators will give the go-ahead for a large phase-three trial involving about 7000 subjects. If that trial is successful the drug can be licensed and sold.
Researchers are not expecting the vaccine to offer 100% protection from HIV. A similar trial of the vaccine in Thailand resulted in varying degrees of protection.
South African scientists have modified the vaccine to make it more potent and trial participants will get an extra injection in the hope that its effects will last longer, said Professor Gray.
“I wish we had done this vaccine trial in South Africa nine years ago, when it went to Thailand.”
This is just one of a range of HIV trials in South Africa.
Next month researchers will give 1700 women in sub-Saharan Africa a drip containing antibodies against HIV. Scientists want to know if giving antibodies regularly confers protection against HIV.
Only a small percentage of patients create this antibody, which protects against multiple strains of HIV. The trial participants will be given a drip once every two months for nearly two years. South African women have been recruited.