South African AIDS Vaccine Initiative Launches Phase I Trial

The South African AIDS Vaccine Initiative (SAAVI) commemorated the launch of the South African arm of a Phase I AIDS vaccine trial at the Emavundleni Prevention Centre in Cape Town on July 20. The purpose of the trial is to evaluate the safety and immunogenicity of two vaccine candidates, developed by researchers in South Africa, which are administered sequentially in a prime-boost regimen.

The trial, known as SAAVI102/HVTN 073, is being conducted in collaboration with the HIV Vaccine Trials Network (HVTN) and the National Institute of Allergy and Infectious Diseases (NIAID), part of the US National Institutes of Health (NIH).

Researchers plan to enroll 36 volunteers at two clinical research centers in South Africa—the Emavundleni Centre in Cape Town and Chris Hani Baragwanath Hospital in Soweto. Twelve volunteers have already been successfully enrolled and vaccinated in the US arm of the study, which is being conducted at the Fenway Community Health Center in Boston.

The prime-boost regimen being tested is comprised of a DNA vaccine candidate followed by a modified vaccinia Ankara (MVA) vector-based candidate, both of which are modified by researchers to carry fragments of clade C HIV, the subtype that is predominant in South Africa, to induce an immune response against HIV. Both candidates were tested in the laboratory and in animal models prior to this study and neither can cause HIV infection.

The launch of the South African arm of the study was significant because the prime-boost regimen was developed by researchers in the country. “We’re seen as the place to test vaccines, now we’ve developed one,” said Anna-Lise Williamson of the University of Cape Town, who led the development of the vaccine candidates. “It usually happens the other way around.”

The DNA vaccine candidate was constructed in South Africa using a plasmid provided by the Vaccine Research Center at NIAID. The MVA candidate was developed by researchers at the University of Cape Town with funding from SAAVI and the NIH. Both candidates were manufactured in the US. SAAVI is the lead program of the South African Medical Research Council (MRC) and was established by the South African government and the energy supply company Eskom in 1999 to coordinate the development of an HIV vaccine for southern Africa.

Anthony Mbewu, president of the MRC, called the launch of this trial a “scientific milestone,” which he said “ensures that South Africa will be better able to design and develop vaccines against infectious agents in the future.”

Anthony Fauci, director of NIAID, said that scientists in South Africa received more NIAID funding last year than any other country outside the US. “You have the intellectual capital and people who are passionate about health, especially in the arena of HIV/AIDS,” he said. Fauci also discussed the “extensive challenges” facing AIDS vaccine researchers.

Despite these challenges, many speakers noted the importance of continuing AIDS vaccine research. “The cost of [HIV] treatment is very high,” said Naledi Pandor, the South African Minister of Science and Technology. “I therefore cannot overstate the importance of the development of a vaccine for the South African population.”