Turning the tide on HIV/AIDS in Africa

09 November 2010

The successful launch of the clinical testing of two new HIV vaccines has created new hope that the HIV/AIDS pandemic can be curbed in Africa.

HIV vaccine testingIn a first for Africa, two HIV vaccines developed by UCT's Institute of Infectious Disease and Molecular Medicine (IIDMM) began clinical testing at Crossroads in Cape Town and in Soweto, Johannesburg last year.

The trial, called SAAVI 102/HVTN 073, is also a milestone for South Africa. The country is one of the few developing nations, and the first in Africa, to have developed an HIV vaccine and put it forward for human clinical trials.

The vaccines are the culmination of eight years of research and development involving scientists across South Africa and globally.

Through joint funding from the South African AIDS Vaccine Initiative (SAAVI) and the US National Institute of Allergy and Infectious Diseases (NIAID), the trial is being conducted with the HIV Vaccine Trials Network and NIAID, part of the US National Institutes of Health.

The vaccine designs are based on HIV subtype C, the dominant strain circulating in Southern Africa.

The US arm of the trial has 12 participants, while the South African arm plans to recruit 36 participants at its two sites.

Professor Anna-Lise Williamson, leader of the vaccine development team and joint staff member of the IIDMM and the National Health Laboratory Services (NHLS) said that reaching this important milestone has been a significant moment for the team.

"An effective vaccine against HIV/ AIDS remains a top global health priority, and it is our hope that the evaluation of these vaccines in clinical trial will provide some important answers that will bring us closer to this goal."

She added that the process has been a team effort in a very real way.

"Translating our discoveries in the laboratory to testing in humans would not have been possible without the support of a large team of people from UCT, together with national and international collaborations," she said.

As part of the SAAVI initiative to develop a vaccine specifically for subtype C, virologist Williamson and her team at the IIDMM surveyed HIV from newly-infected patients and selected genes that best represented local strains. Building on this, she and Carolyn Williamson (from the same institute) refined the two vaccines now on trial by incorporating additional subtype-C genes and modifications to make them more effective.

The trials are using what is known as a prime-boost response: the synthetic DNA vaccine is given to prime the body's immune response, followed by the MVA vaccine which should boost the immune response. MVA is made from the Modified Vaccinia Ankara virus, similar to the smallpox vaccine – so volunteers must not have received the smallpox vaccine before.

The SAAVI 102/HVTN 073 vaccine trials aim to test if the candidate vaccines are safe for people, and how their immune systems respond. Trial participants also have to be HIV-negative and at a low risk of becoming infected. If the results are promising, phase II trials will be conducted, also to test vaccine safety and immune response, and phase III trials would test if the study vaccine is effective in preventing HIV infection or slowing its progression to AIDS.

The South African trials are taking place at the Emavundleni Centre in Cape Town (part of the The Desmond Tutu HIV Centre) and Chris Hani Baragwanath Hospital in Soweto.

Launched in 2005, the IIDMM is focused on infectious diseases, particularly those that threaten sub-Saharan Africa, such as HIV/AIDS and tuberculosis.

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