Although more than 60
trials have been conducted worldwide, none has been into subtype C, the
most-common form of HIV in sub-Saharan
More than 90% of
HIV-positive people worldwide are infected with subtype C, but trials have
focused on subtypes A and B most commonly found in the
The research is fascinating. Some believe canaries might hold the key to a successful Aids vaccine, but then again it could be antibodies found in small monkeys called macaques. It could even be present in an infection found in horses.
But, no matter how you look at it, it will probably be another seven to 10 years before a vaccine is found - if ever.
Scientists say the virus is so complex it may be impossible to find a vaccine.
If one is found, it won't cure Aids, but could help prevent the virus infecting HIV-negative people, particularly those who aren't sexually active yet.
Bodies producing antibodies
Of the 20 HIV-negative volunteers, 10 will be injected with a small amount of clade (subtype) C of the virus, and 10 will be vaccinated with placebos (essentially water). No one - neither doctors nor volunteers - will know exactly who gets which.
The live human immunodeficiancy virus isn't used in the trials because of safety fears. What is used is one or more proteins of HIV.
Those who are injected with clade C will probably test HIV-positive for up to a year after the trials.
This is because their bodies are producing antibodies (fighter cells) to combat the virus.
The South African Medical Research Council responsible for conducting the trials will try to ensure that volunteers won't be discriminated against when applying for a job, life insurance, a housing bond, or a visa to countries that demand HIV tests before you visit.
Trials are also taking
part elsewhere in the world - in
Scientists have been
working on an Aids vaccine for 17 years. Trials have taken place in
Clade C, prevalent in
So far, no vaccine sample has been produced that can be used for more than one of the nine HIV subtypes. - African Eye News Service