SA begins first phase II vaccine trial

UCT's Desmond Tutu Institute for HIV Research at the Institute for Infectious Disease and Molecular Medicine (IIDMM) is one of three sites for the phase II trial in South Africa to test the safety and immunogenicity of tgAAC09, a preventative HIV vaccine candidate that is based on HIV subtype C. This subtype of the virus is the most prevalent in southern and eastern Africa.

Dr Linda-Gail Bekker is the principal investigator at the UCT site.

The trial is being run under the auspices of the International AIDS vaccine Initiative (IAVI) and Targeted Genetics Corporation. This is the first phase II vaccine trial to be held in this country. Candidate vaccines that are proven to be safe in phase I trails move on the phase II trials, allowing investigators to test the immune response in humans and acquire more data on safety.

The other two sites of the trial in South Africa are the Perinatal HIV Research Unit, Chris Hani Baragwanath Hospital in Soweto, with Dr Eftyhia Vardas as the principal investigator, and the Medunsa Campus of the University of Limpopo, with Professor Anwar Hoosen as the principal investigator.

IAVI also plans to test the vaccine in Zambia and Uganda, pending regulatory approval in those countries.

"We are pleased that South Africa has taken a leading role in the testing of vaccine candidates, given the medical and humanitarian promise a preventative vaccine holds," Vardas said. Vardas is the national protocol chair of the trial.

South Africa approved its first HIV vaccine trials in 2003, including one sponsored by IAVI. In 1999 the government created the South African AIDS Vaccine Initiative (SAAVI) to coordinate the research, development and testing of HIV vaccines. SAAVI is the national coordinating body for vaccine research in South Africa, working with both national and international partners.

The trail should take around 18 months to complete and will enrol 78 volunteers, men and women, who are in good health. tgAAC09 is designed to elicit two different types of immune responses: an antibody response and a cell-mediated response. The vaccine consists of an artificially made copy of the HIV virus and cannot cause infection or AIDS.

IAVI estimates that there are 30 preventative HIV vaccine candidates in human trials on six continents.