The only HIV vaccine in the world that worked slightly in Thailand also seems to work on South Africans.
Despite being fatter than Thai people and exposed to a different strain of HIV, 100 South Africans responded in a similar way to a vaccine that protected about a third of Thai people against HIV.
“We were really excited to see the vaccine got exactly the same (immune) responses in South Africans as in Thailand,” said Medical Research Council President Dr Glenda Gray at the inaugural HIV Research for Prevention conference that opened yesterday.
The Thai vaccine, known as RV144, protected 31 percent of people who received it in a massive clinical trial in Thailand involving 16 400 people.
Once the Thai results were known in 2009, the global HIV research community decided that is was a priority to test the vaccine in a country with high HIV rate, Gray told Health-e News.
For the past two years, the immune responses of the 100 South Africans vaccinated in Soweto, Klerksdorp and Cape Town have been under the microscope.
“We had to be pragmatic, said Gray. “The vaccine had to work for fat people, women and people who drink alcohol because we South Africans drink a lot.”
“If we meet (criteria), we can go straight into a Phase 3 trial of 7000 people by the end of 2016”
Over half the women in the South African study were overweight or obese.
Satisfied that the South Africans reacted as hoped, researchers are now preparing for a bigger trial with a modified vaccine that contains the strain of HIV most common in southern Africa.
If successful, trial could grow quickly
This trial, involving 200 people, starts in January but could leapfrog into a massive R1-billion trial within a year if the people respond according to the Thai trial.
“We have already set our ‘go or no go’ criteria based on the Thai trial and if we meet these, we can go straight into a Phase 3 trial of 7000 people by the end of 2016,” said Gray.
The Thai trial combined two vaccines. The first aimed to prime people’s immune systems to recognise the types of HIV most common in Thailand (sub-types E and B) and the other, injected later, aimed to boost their immune systems to fight infection.
The “primer” vaccine now has to be modified to contain HIV sub-type C, which is most common in South Africa.
Discussions have already been held with the Medicines Control Council to license the vaccine by 2019 if the Phase 3 trial goes well, and also to vaccinate children along with the current HPV vaccine to prevent cervical cancer, said Gray, who added that even if the vaccine only gave 50 percent protection, government would probably still license it.
“Medical male circumicision offers up to 60 percent protection against HIV, and we are rolling it out,” said Gray.
Meanwhile, Science and Technology Minister Naledi Pandor opened the conference by appealing to African governments to invest in health research to “assume responsibility for finding solutions to our problems”.
Pandor welcomed the inaugural conference, which aims to unite all biomedical efforts to prevent HIV, from vaccines to microbicides and condoms.
“The challenge is to translate our new health knowledge into products that are effective, affordable and accessible,” added Pandor.
An edited version of this story was first published in the 29 October edition of the Pretoria News.