South Africa is expected to begin it's first Aids vaccine trials at the end of September, following the approval by the Medicines Control Council (MCC) of a second HIV preventative vaccine candidate. The trials will form phase one of three trials that could take seven to 10 years to complete.
The most recently approved vaccine candidate, named HIVA.MVA, was designed by the University of Nairobi in Kenya and the University of Oxford in the United Kingdom.
Phase one human trials of the vaccine candidate have already have been completed in Kenya and the UK and are underway in Uganda.
The trials are sponsored by the nonprofit International Aids Vaccine Initiative (IAVI).
In June, the MCC gave approval for a phase one trial of AVX101, designed by the US biotechnology firm AlphaVax Inc.
The trial will be conducted by the HIV Vaccine Trials Network of the US government's National Institute of Allergy and Infectious Diseases.
A Phase One trial of AVX101 was recently completed in the US.
The trials of HIVA.MVA and the AlphaVax candidate are separate, but will be conducted at the same sites: the Perinatal HIV Research Unit (PHRU) of the University of the Witwatersrand at the Chris Hani Baragwanath Hospital in Soweto and the SAAVI HIV Vaccine Research Unit at the Medical Research Council in Durban.
Professor James McIntyre, Principal Investigator for the Aids vaccine trial sites in South Africa, said: South Africa's research community has linked hands with researchers cross three continents-Europe, North America and Africa-in the global effort to find a vaccine against Aids.
There is no risk of either HIVA.MVA or AVX101 causing HIV infection or Aids.
Neither vaccine candidate contains HIV or any substance from HIV infected individuals.
A preventive vaccine would be given to people who are HIV negative, to prevent HIV infection.
IAVI's HIVA.MVA and AlphaVax's AVX101 employ different vaccine design strategies.
HIVA.MVA uses a vaccine strategy called modified vaccinia Ankara, a variant of the basis for the smallpox vaccine.
AVX101 uses a carrier for it's vaccine called the Venezuelan Equine Encephalitis alphavirus vector.
By studying different vaccine design strategies at once, rather than one at a time, South Africa will help reduce the time needed to identify which is the most effective, said Dr Seth Berkley, President and CEO of IAVI.
In the search for an Aids vaccine, speed is of the essence.
A preventive vaccine is our best hope to end the spread of an epidemic that infects 15,000 men, women and children around the world every day, Dr Berkley said.
The Phase one trials will initially enroll roughly 50 volunteers each.
Their aim is to test safety and gather preliminary data on the ability of the vaccine candidates to stimulate the immune system.
By conducting the HIVA.MVA and AVX101 trials side by side, South Africa will help gather data to address how an AIDS vaccine may be able to combat the varying subtypes of HIV that are circulating.
IAVI's HIVA.MVA is based on subtype A, which is common in east Africa. AlphaVax's AVX101 is based on subtype C, the subtype most common in South Africa.
Ideally, a single Aids vaccine will be highly effective against all subtypes of HIV, said Dr. Wayne Koff, IAVI's senior vice president for Research and Development.
Preliminary indications are that both of the vaccine candidates currently approved for testing in South Africa hold promise for meeting this goal, but only human trials will tell us for sure. (Source: Sapa, Business Day, 26 August 2003)