Many concerned South Africans, including radio DJs, have volunteered to be injected with the country’€™s first HIV/AIDS prototype vaccine, according to HIV/AIDS expert Professor Salim Abdool Karim.

“We haven’€™t selected the 48 subjects yet who will be part of the Phase 1 trial, as we don’€™t know when exactly we will start and don’€™t want to create expectations,” said Prof Karim, who is deputy vice-chancellor of research at Natal University.

“But people have been phoning, writing and emailing, saying they would like to take part. We are keeping a list of potential volunteers. We will need several hundred volunteers for vaccine trials and I would encourage potential volunteers to contact us by the end of the year.”

The 48 people to be tested in Durban need to be HIV negative, in good health and at low risk of HIV infection, said Prof Karim.

The phase 1 trial will simply test the safety of the vaccine for use in humans, as the sample size is too small to test whether it will be effective in preventing HIV. Phase 2 would involve about 150 people and its main aim will be to see whether the vaccine stimulates an immune response to HIV (immuno-genicity) in humans. A phase 3 trial would involve more than 10 000 people to test whether the vaccine prevents HIV infection.

The initial trial will test 12 subjects at a time. The first 12 will be tested with a very low dose of the vaccine and monitored for any serious adverse effects. The dose will be increased incrementally each time if it is proved to be safe.

“If there is serious toxicity that requires hospitalisation, we will stop the study and review the data,” said Prof Karim.

Prof Karim said that it was impossible for subjects to get HIV from the vaccine, as it only included a few specific genes of HIV. A special test that picks up HIV, called a Western blot test, would be able to show whether subjects had contracted the HI virus elsewhere.

“The vaccine would only reflect in one band of the Western blot test, so if any other bands show up the subject has picked up the virus elsewhere,” said Prof Karim.

He added that while the prototype vaccine had been ready from late last year, the trials could not begin until all the scientific protocols had been completed and a high quality vaccine had been manufactured. This was being done through the US vaccine company, Alphavax, which is a partner in the trial.

Once these “standard production questions” had been dealt with, the vaccine initiative would be able to submit its application for a trial to the Medicines Control Council.

“We hope to make the application by the end of the year,” said Prof Karim. “But this is not a simple procedure and we have learnt that you cannot predict biological systems.”