Despite Africa contributing to 17 per cent of all AIDS vaccine trials, the continent, however, still lacks capacity in basic sciences; there is neither equipment nor the technical know-how to carry out assays locally. Worse, according to Dr. Gaudensia Mutua, Kenya AIDS Vaccine Initiative & International AIDS Vaccine Initiative, although an estimated 30 trials have been done in seven African countries, the bulk of studies are however sponsored by the International AIDS Vaccine Initiative and the NIAID with minimal contribution from Africa.
Speaking at the First Africa Science Journalists conference in Nakuru, Dr Mutua said: “Although Africa opts to send scientists abroad with the hope that they will be back with the know-how, the governments’ failure to equip their laboratories as well as improve the working environments for scientists’ forces scientists to stay put in the countries they went to study.”
She added that in the long run, Africa ends up losing people to developed nations. “People with skills will not wish to come back. To do what when there is no equipment?”
The continent is thus left in the vicious cycle.
Dr Mutua noted that to solve the problem, African countries are now turning on south to south partnerships with South Africa, playing a bigger role in helping build capacities of other African countries.
Speaking about Kenya, Dr Mutua said currently scientists working in Kenya are looking at different vaccine delivery methods. They are adding adjuvants into vaccines to make immune systems more robust as to produce needed immune responses to candidate vaccines.
“Right now, we are using different vectors with capacity to replicate as Adeno5 vectors, since previously used have been found to be weak and thus cannot help the candidate vaccines under trials stimulate needed immune responses,” said Dr Mutua.
She said this has been necessitated by the realization that many of the current HIV vaccine strategies have been found limited in two key ways. First, most current viral vectors that deliver HIV immunogens are engineered, for safety reasons, not to multiply as any normal virus would and that most HIV vaccine vectors are not devised to induce immunity in mucosal tissues.
According to Dr Mutua, after HIV enters the body, it begins infecting CD4+ T cells in the mucosal tissues that line the inner cavities of the body, most significantly those of the gut.
She said any effective vaccine must train the cell-mediated immune response—primarily through CD8+ or cytotoxic T cells—to detect infected cells and destroy them before HIV can establish a reservoir of persistent infection.
“The cell-mediated immune (CMI) response is essential to vaccine responses and serves to mop up viruses that slip past the antibody assault, helps to control infection for several years in HIV-positive people, and has been shown to play a major role in those who suppress HIV infection for extraordinary lengths of time.
According to Mutua, AIDS vaccine research is still critical given that HIV infection is spreading despite current efforts.
Globally, 33 million people live with HIV. On any given day, 7,500 new HIV infections are noted.
Treatment is expensive and has side effects. Coupled with drug resistance and sustainability concerns only makes the sense of keeping pressure on global leaders to continue funding AIDS vaccine.
Source: Africa Science News
