Challenges in HIV/AIDS vaccine research

Despite optimism about the development of an HIV/AIDS vaccine in Africa, researchers still face many hurdles, scientists said this week at the launch of the African AIDS Vaccine Programme (AAVP).

Dr Pontiano Kaleebu, a leading researcher with the Uganda Virus Research Institute, said at the launch of the AAVP in Cape Town, South Africa, that only two phase-one trials had been completed in Africa to date.

There are three phases in human clinical trials. Phase-one involves 20-60 healthy, uninfected volunteers at low risk of HIV infection, and tests for safety.

He said the lack of research was "partly a consequence of neglect and partly of slow and complex decision-making". Some African nations required the consensus of many officials at every level of government before a clinical trial can begin.

There is a growing consensus that an AIDS vaccine is the best long-term hope to control the AIDS epidemic, especially in developing countries.

"A vaccine for Africa would be the best long-term preventive measure against AIDS ... this initiative, could help address the health and development tragedy that AIDS has become for many African countries," Peter Piot, Executive Director of UNAIDS said in a statement last week.

But the regulatory process in most African countries is slow, unpredictable, and sometimes non-existent, as guidelines for such research have not been defined yet. In Uganda, it took two years and 9 committees to approve the vaccine trials conducted there, as there were no set procedures, Kaleebu noted.

Ethical and legal requirements, such as obtaining informed consent for volunteers to participate in the trials were not as straightforward in Africa as there were cultural issues involved. In many African cultures, women need permission from their spouses and cannot give individual consent.

Researchers also had to assess whether trial participants adequately understood the purpose of the trials, particularly in rural settings. In Uganda, compensation for the treatment of research-related injuries during the clinical trials had led to many participants taking advantage of this, undermining the whole process, Kaleebu said.

Effective family planning was important, as the risks of the candidate vaccines to the foetus were still unknown, he added.

Developing a physical infrastructure of clinics, laboratories and state-of-the-art technology was particularly difficult in areas where basic utilities such as power and water were not easily available.

The conflict between creating a therapeutic or preventive vaccine was a "difficult issue" as those already living with HIV/AIDS also wanted a vaccine, he said.

"Many Africans are skeptical about trials as they believe they are being used as guinea pigs by the developed countries," he told PlusNews.

According to Kaleebu, these challenges did not mean there was no future for vaccine trials in Africa, as Africa was gaining momentum in its research. There were a number of trials lined up in South Africa, Nigeria, Cote D'Ivoire and Ethiopia and other countries, he said.

AAVP chairman Dr Malegapuru Makgoba told journalists that the first phase-one effectiveness trials on a candidate vaccine for HIV sub-type C - the variant prevalent in southern Africa - could start in South Africa soon, and was only awaiting regulatory approval.

However, this process could not be rushed. "You need high ethical standards ... we have to be sure that the day we start injecting we are not going to be facing the consequences of destroying the whole process," he said.