HIV/AIDS scientific sessions
Posted by Ilona van den Brink on 23 October 2009 at 17:36
By Ochieng’ Ogodo
An effective AIDS vaccine could be the ultimate bullet to shatter the scourge that has ravaged humanity, especially in sub-Saharan Africa. However such a discovery has been very elusive for the last twenty years. Dr Anatoli Kamali, epidemiologist and Head of the HIV Intervention Programme at the Medical Research Council of Uganda says there have been advances in research in HIV/AIDS over the past years though the magic bullet is yet to be reached.
Although none of them have proved effective against the disease, every failure, Kamali explained, has had great lessons in them on how to progress with the search for a vaccine.
“Most of these lessons have been contributed by the institutions in the developing countries, especially in the sub-Saharan Africa in partnership with colleagues and funding agencies in the North,” he said.
The best hope to control the epidemic is to get a vaccine but there have been huge challenges in developing one. Dr Kamali: “This is because the virus rapidly destroys the immunity system. It also changes itself very fast and goes for the destruction of the keys cells,” he said.
Trials, he stated, have been ongoing but none has shown efficacy except for a recent one in Thailand. Scientists are still trying to develop a vaccine, which might take a few more years but for every failure they have learnt a lot which might be very useful in future.
According to Dr Kamali there has been a lot of capacity building to enable Africa to contribute to the search for a vaccine and to scale up treatment for those infected with the virus. Partnerships with the north like EDCTP and International AIDS Vaccine Initiative (IAVI), he said, has been very instrumental in the building of this capacity.
In HIV prevention research, he said, many clinical trials evaluating various biomedical products or interventions have been conducted; some complete, some ongoing while others are being planned.
“Currently,” he said, “there are about 36 major prevention clinical trials that have been done but only four have shown impact on HIV transmission, and three out of the four were circumcision trials in Kenya, Uganda and South Africa while the fourth one was on Sexually Transmitted Infections (STIs) conducted in Mwanza, Tanzania.”
There are also many trials going on, mainly focusing on vaginal microbicides and the use of antiretrovirals (ARVs) in HIV transmission medically referred to as Pre-Exposure Prophylaxis (PREP) studies.
Early this year, he said, there were encouraging results from NIH funded trials in South Africa, which evaluated the safety and effectiveness of vaginal microbicides BufferGel and 0.5% PRO 2000/5 Gel for the prevention of HIV infection in women. The microbicide PRO 2000/0.5% Gel showed promise. “It showed a 30 percent reduction in HIV transmission among women but the 30 percent reduction was not significant. There is need to evaluate that product, and to get more evidence from other trials to show efficacy,” said Kamali.
He said there is another large trial using the same product and the same gel concentration involving over 9000 women in six centres in Africa; Masaka in Uganda, Mwanza in Tanzania, Mazabuka in Zambia, Johannesburg, Durban and Africa Centre in South Africa.
The results will be reported in early December and researchers, policy makers and pharmaceutical products companies are keen on the ongoing trial. “The future of microbicides is going to be the evaluation of ARV-based microbicides. There are several in early clinical trials like tenofovir 1 percent gel and maraviroc,” said Kamali.
The International Partnership for Microbicides (IPM) is evaluating better delivery methods like a vaginal ring with better advantages of adherence.
Papa Gallo Sow of Université de Bambey in Senegal said further research is needed in knowledge on microbicides among women and that more information is needed for them.
“More information is also needed for health care professional about microbicides and educational and counselling programme on microbicides must be set up.”
Suzan Nakate of the Infectious Diseases Clinic, Kampala, Uganda presenting on Barriers to adherence to clinic appointments in a free urban HIV care facility said that at registration, patients are often in poor health but resume their productive capabilities after HIV care and treatment. Gradually they begin missing appointments, and a recent study showed patients who do not attend regular HIV care are significantly more likely to die than those who maintain good contact with their HIV clinic.
She said it was important to look at contacts of patients who miss appointments and that patients on unscheduled visits should be allowed to reschedule at their convenience even through a phone call.
Financial support, especially where patients are unable to meet extra costs like bus fare to visit clinics need to be addressed and quality services in close health centres.
“The effectiveness of the treatment of HIV/AIDS is dependant on clinic adherence,” she said. Disclosure, social and financial support should be addressed to overcome the obstacles to clinic attendance.
All the above mentioned aspects, she remarked, are important in the management of HIV/AIDS treatment in resource-limited settings.
