Ugandan and American Aids researchers have begun the first ever clinical trial of a vaccine to prevent mother-to-child transmission of HIV through breast-feeding which, if successful, could prevent at least 25,000 infections in new-borns in East Africa alone.
In the first phase of the trials the researchers will be testing whether the vaccine, formally known as ALVAC-HIV, is safe for use in children, following which they will study whether it can stop the transmission of the Aids virus to a suckling baby through breastmilk. Preliminary results are expected in mid-2007.
According to the UNAids, breast-feeding by HIV-positive mothers accounts for more than a third of all infections in new-borns, translating to about 1,800 children each day around the world. In Uganda alone, at least 8,000 of the country's 22,000 infections in children each year occur as a result of breast-feeding.
The Ugandan study will initially involve 50 children born to HIV-positive mothers, of whom 40 will randomly receive the test vaccine and 10 will act as controls.
It will be conducted at the Mulago Hospital by researchers from Makerere University and the John Hopkins University over a two-and-a-half year period. Once enrolled, the subject infants will be injected with the test vaccine, manufactured by Sanofi Pasteur, in four separate doses over a period of three months.
Aids experts say that an effective vaccine to help prevent mother-to-child transmission of HIV through breast-milk is the best possible way to curb the problem, as healthy alternatives to breast-feeding such as infant formulas are usually not available to most mothers in poor countries. In most African setups, it is also not practical to discourage breast-feeding for cultural reasons.
The ALVAC-HIV vaccine is one of at least five HIV vaccines under study across the continent, all of which involve adults. Previous studies in Uganda have shown it to be safe when administered to this group. The largest trials involving the vaccine are being undertaken in Thailand, where 16,000 volunteers are involved.
Elsewhere, Kenya's lakeside city of Kisumu has been selected to host a study into a new microbicide to prevent the transmission of genital herpes, an infection which afflicts more than 30 per cent of adults in the region and which has been implicated in the transmission of HIV.
The microbicide, known as VivaGel (TM), will be tested concurrently in Kisumu and at a site at the University of California, Los Angeles.
The trials will be funded by the US National Institute of Allergy and Infectious Diseases, which is part of America's National Institutes of Health.
At least 30 women aged between 18 and 24 years will be enrolled at each site to help establish the safety of VivaGel TM when applied twice daily for 14 days in healthy women.
Recruitment for study volunteers in Kisumu will start in the next two weeks. Other studies on the microbicide are currently going on to establish whether it can also protect against HIV infection.
VivaGel (TM) was developed by the American medical research company, Starpharma Holdings Ltd. The company specialises in developing drugs from new molecules known as dendrimers.
"This trial represents a key milestone in the development of VivaGel (TM), supported by our clinical collaborators in the US and Kenya," Dr Jackie Fairley, chief executive of Starpharma, said in a statement announcing the Kisumu trials. "We consider prevention of genital herpes to be a commercially important indication for VivaGel (TM)."
Genital herpes is among a slew of sexually transmitted diseases which Aids experts say facilitate the transmission of HIV by creating sores that act as doorways for the Aids virus during unprotected sex.
The disease is prevalent in both poor and rich countries, with between 15 and 25 per cent of adults in North America and Europe being infected with the disease. In the United States alone, about 50 million people are estimated to have the infection.
Together with HIV, the disease is responsible for the growing interest among medical researchers in microbicides.