HIV vaccine breaks new ground

By Khanyi Magubane

A major breakthrough in the research, development and testing of HIV vaccines in South Africa is on the cards, following an application by the South African Aids Vaccine Initiative to start human clinical trials on their new vaccines. The application has been sent to the Medicines Control Council (MCC) for approval.

Researchers from the University of Cape Town (UCT) have developed two test HIV vaccines, which, if approved, will be the first entirely South African-developed products to reach the human trials stage since the Aids vaccine research process begun.

Before a vaccine is given the thumbs up, it is taken through a number of clinical trials. At that stage, it’s called a test vaccine. If the test vaccine fails any of the clinical trials, it is discarded.

Dr Glenda Gray, Director of the Perinatal HIV Research Unit at Johannesburg’s Chris Hani Baragwanath Hospital, will be chairing phase one of the clinical trial. She says this phase of the trial will include 12 Americans and 36 South African volunteers. Gray says she is positive about the safety of the vaccine. “The vaccine has been tested in America on animals and similar vaccines to the one we will be testing have been tested on humans before, so we have a good idea what the safety profile will be.”

Phase one of the trials will test the tolerability of the two vaccines, Saavi MVA-C and Saavi DNA-C2, on humans – specifically, the response of the immune system. “We want to see if there is a strong immune system response to specific doses of the vaccine,” says Gray. All the participants have been carefully chosen to fall within the low risk sexual behaviour category and their risk of passing on the virus is very minimal.

Gray further explains that if the first phase of the clinical trials is successful, Saavi will then conduct phase two, which will now involve hundreds of participants and will involve a more intricate look at the immune system’s response to the vaccine.

Should the trials continue on a success path, the process will then advance to phase 2b, which will be the “protection” phase. Participants who fall into the high-risk category will be used in the trial to once again test for the immune system’s response to the vaccine, as well the vaccine’s ability to protect the immune system from the disease. The vaccines were specifically designed to target the strain of HIV-1 subtype C, which is the most prevalent in Southern Africa.

Researchers from UCT’s National Health Laboratory Service developed the two vaccines with the help of funding received from Saavi since 2000. The project also received some funding from the National Institutes of Health in the United States. In South Africa, the departments of Science and Technology and of Health, as well as electricity utility Eskom, have also backed the project.

Following 12 failures in the past few years, including five last year, Gray says Saavi is positive about these clinical trials. “We are very hopeful. We are using a completely different strategy this time. The vaccine is very clever and we are using a new biological platform.”

The process between Saavi and the MCC will include a thorough examination of the safety of the vaccine to use on humans, which will be conducted according to the MCC’s own testing procedures. This process is expected to take an estimated three months before a final decision is reached.

HIV/AIDs and South Africa

At the end of 2006, one in nine or 5.5 million South Africans were living with HIV, with a prevalence of 18.8% in the adult population. HIV prevalence is not yet declining although it has stabilised among young people 15-24 years, reports UNAids.

The figure reported by UNAids is 8.8% higher than the results of a national South African HIV survey conducted in 2005, commissioned by the Nelson Mandela Foundation. According to the survey, entitled “South African National HIV prevalence, HIV incidence, behavior and communications survey 2005”, researchers estimated that 10.8% or 4.8 million of all South Africans aged two years and older were living with HIV in 2005. Among those between 15 and 49 years old, the estimated HIV prevalence was 16.2% in 2005.

In an increased bid to better understand ways in which to manage the Aids pandemic in the country, more than 4 000 scientists, activists and medical experts gathered in Durban for the third South African AIDS conference in June last year. The conference was conducted under the theme, “Building consensus on prevention, treatment and care”. At the end of the week-long event, an extensive conference declaration was taken, covering seven key areas: HIV testing stategies, social and behavioural interventions, infant feeding, long-term effects of anti-retrovirals, male circumcision, female condoms, and new prevention strategies.

The Department of Health has also adopted a HIV and AIDS and STI (sexually-transmitted infections) strategic plan for South Africa, 2007–2011. In its report of the strategy, it states, “Whilst the two main goals of the Operational Plan for Comprehensive HIV and AIDS Care, Management and Treatment for South Africa are to provide comprehensive care and treatment for people living with HIV and AIDS as well as to facilitate the strengthening of the national health system, the National Strategic Plan 2007-2011, is not a plan for the health sector alone. Instead, it seeks to be relevant to all agencies working on HIV and AIDS in South Africa, within and outside the government. The underlying basic premise is the recognition that no single sector, ministry, department or organisation can by itself be held responsible for the control of HIV and AIDS.”

Useful links

Avert – international aids charity

Medical Research Council

UNAids

South African Aids Vaccine Initiative

Third South African Aids Conference