By Onche Odeh
Scientists currently working on various candidates of vaccines against HIV have conceded that it may take another 20 years to catch up with the virus using a vaccine. Daily Independent’s Head, Education & Science, Onche Odeh, was in Kenya recently where he interacted with some of these scientists who confessed to the fact that the virus has been evasive to its chasers.
The world may still have to wait 20 or more years before the first ever vaccine against the Human Immuno Deficiency Virus (HIV), which causes the acquired Immune Deficiency Syndrome (AIDS) could be announced.
Although several attempts have been made at creating a vaccine, scientists have been frustrated by the dodgy nature of the virus that seem to have eluded most known scientific methodologies for vaccine creation.
Scientists at Kenyan AIDS vaccine Initiative (KAVI) and the Kenyan Medical Research Institute (KEMRI) working on the virus and various HIV vaccine candidates are not particularly pleased that a vaccine antidote, which would provide ultimate protection against the virus that kills millions worldwide may still not come until 20 to 30 years from now.
Prof. Omu Anzala of the University of Nairobi and Programme and Director of KAVI told who explained why the path to finding a vaccine protection for HIV may still be some years ahead, said, “The HIV virus behaves quite differently from every other known pathogen, hence making it very difficult to trail and study.”
His explanation may say differently about the virus for which many think has been the most studied and understood of all pathogenic viruses.
Anzala who spoke with Daily Independent in Kenya said, “Sometimes around 1995-96, scientists thought they had known so much about HIV and that it wouldn’t take long for a vaccine to be developed. But the discoveries that trailed their researches have shown that we were wrong.”
Giving reasons why the virus has become even more elusive, Anzala said, “95 per cent of people who get Hepatitis are able to recover and once this happens the body recognises the virus the next time it comes. But this is not the situation with HIV. No one survives it, and when it is passed on to another person, what you see is remarkably different from the original copy, which is a reason scientists are unable to keep track of its.”
According to him, the immune system of humans is not designed to cope with the virus, adding that, “rather than deal with it, the human immune system finds itself always chasing the virus which mutates so fast.”
At the Kenyan Medical Research Institute (KEMRI), HIV researcher, Vincent Okoth, said the timeline for the development of a vaccine makes it impossible for any vaccine on HIV to be developed within the next ten years.
“Most of the works on HIV vaccine candidates are in phase I, which takes at least two years to end and another five years to properly transit to Phase II,” he said.
“Often times, we discover that the vaccine that we began developing within the seven years becomes less effective against current strains of the virus, which takes the scientist back to the beginning,” Okoth disclosed.
He said, most times the virus behaves differently when it is mimicked or cultured from the way it does inside the human body, which he said is a major frustration for people working on vaccines against it.
Currently phase I trials of two HIV vaccine candidates (which is primarily to ascertain their safety) are ongoing at KAVI. Anzala disclosed that the trials, which started in 2011, would be completed by December 2012 and January 2013. This is not to be certain as the centre has the issue of compliance by clinical trial volunteers and funding to deal with.
“Often times, we have problems with volunteers who would start and, may be due to their work schedule or other activities are unable to follow through. This distorts the trials a lot,” head of the Laboratory at KAVI, Prof. Bashir Farah, said.
Amid all of these frustrations, the scientists have some reasons to be optimistic.
“It is interesting to inform you that we discovered from here first that some people were uninfected by the virus despite being exposed to it, which we later found to be due to the fact that those who were not infected lacked a special kind of receptor that enables the virus to bind to the protein that aid its development,” Anzala disclosed.
The virus could stay for as long as 10 years in the body without any symptoms. However, when it grows, it acquires the ability to change its own structure (mutate), a characteristic that enables it to become resistant to previously effective drug therapy.
Most drug therapies used in HIV treatment are to prevent damage to the immune system by the HIV virus and to halt or delay the progress of the infection to symptomatic disease. However, scientists say the best combination of drugs for HIV has not yet been found, as most of them are toxic and not tolerable by the patients. This is a reason they are desperate for a vaccine protection against it.