Health 
African scientists launch vaccine strategy for the continent

The call for an HIV vaccine for Africa comes amid mass field trials, known as Phase III, now taking place with 8000 volunteers in the US and in Thailand. Initial results are expected by the end of 2001 but the strains of HIV are different in these two countries than in Africa. 

"That would be the ultimate irony – success with a vaccine that is useless in Africa," said Dr José Esparza, Coordinator of the WHO-UNAIDS HIV Vaccine Initiative. The only small-scale HIV vaccine trial in Africa was conducted last year in Uganda. No vaccine trials based on African subtypes of HIV are underway, although they are expected to start within a year in Kenya and South Africa.

Two decades into the HIV epidemic, sub-Saharan Africa continues to bear a disproportionate burden of HIV infection. Two-thirds of all people with HIV/AIDS live in sub-Saharan Africa and in 16 African countries, 10% or more of the adult population is already infected with HIV.

Although scientists agree that a preventive vaccine remains the best long-term solution to controlling the HIV/AIDS epidemic, this should not be done at the expense of existing preventive interventions, which should be continued and strengthened.

"A few vaccine development efforts are being prepared in Africa, and these need to be promoted and reinforced," said Dr William Malegapuru Makgoba, President of the Medical Research Council of South Africa, who spearheaded the South African AIDS Vaccine Initiative (SAAVI). Several African countries have participated in international projects, including other HIV prevention trials, but infrastructures and capabilities to conduct vaccine trials are virtually non-existent in Africa.

The African strategy was preceded by a declaration in Nairobi on 14 June in which 40 leading African scientists pledged to use their own "personal and collective commitment and expertise in the development and implementation" of an HIV vaccine strategy specific to Africa. They hope to network extensively, and to bring together the various individual and at times disparate approaches to accelerate the development and future use of HIV vaccines in Africa.

The strategy makes it clear that the "proactive participation of African scientists, institutions and the community" will be essential to develop HIV vaccines for Africa as quickly as possible.

"Our contribution to HIV vaccine development will not only be of benefit to Africa," said Dr Malaki Owili, Secretary of the Society on AIDS in Africa (SAA), "but it will also benefit other parts of the world that are in need of a vaccine." Because of the high number of infections in Africa, trial results may be obtained more quickly than in other parts of the world. In addition, any data collected in Africa from vaccine trials will also be useful elsewhere.

Major commitment by the African scientific community will also enhance the quality of the trials. "Our full involvement will ensure that these trials are conducted with the highest ethical and scientific standards," Dr Owili added.

The African strategy will be translated into a plan of action by the end of the year and will be guided by a range of principles including transparency, collaboration with other efforts, sustainability, ethics, respect for human rights, community participation, and inclusion of all countries.

The strategy is not expected to yield a new vaccine overnight because vaccine research is a lengthy process. The first human trials of an HIV vaccine took place in the United States in 1987. Since then, thousands of volunteers have taken part in trials of some 30 different candidate vaccines. Before reaching Phase III trials, a candidate vaccine undergoes stringent testing in animals and human volunteers. In Phase I trials, 20-50 human volunteers participate, with the number broadened to 200-500 in Phase II. These trials provide important information on whether a potential vaccine is safe. Only once that has been ascertained does a candidate vaccine move on to Phase III, or large-scale trials. These trials are highly complex but are the only way of verifying whether a product protects against HIV or AIDS. 

"A safe and effective preventive vaccine that is accessible and affordable in Africa is our best hope to control the AIDS epidemic in our continent," concluded Dr Owili.

Already, 18.8 million people around the world have died of AIDS and more than 34 million are living with HIV or AIDS, 24.5 million of them in sub-Saharan Africa. Of the 2.8 million AIDS deaths in 1999, 2.2 million took place in sub-Saharan Africa.

Source: UNAIDS 

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