With great fanfare yesterday (30 November), the health services in South Africa launched clinical trials for a new vaccine against HIV. The study (HVTN 702) will involve vaccinating 5400 HIV-negative sexually-active participants aged 18 to 35, and giving them five boosters over the 12 months from the initial vaccination. With an estimated 7 million people living with HIV, South Africa still has the highest HIV burden in the world. This, combined with relatively good health infrastructure (for the developing world), and world-class research facilities make South Africa the country of choice for the new research.
The vaccine being tested in South Africa is very similar to the one that offered hopeful results in a 2009 trial in Thailand (RV144). The South African experiment has a different administration regime to the Thai trial, as well as different adjuvant (agent designed to increase the effectiveness of the vaccine under trial). The Thai trial yielded less-than-conclusive statistics. Some scientists interpret the result as a 30% reduction in transmission rates of HIV. Others are considerably less sanguine. In the South African experiment, researchers hope after 3 years to see a 50% reduction in the rate of transmission of HIV in the study group. If, during the trial, the vaccine appears to be working, then additional studies will begin in other parts of the continent and the world. This whole project is very optimistic, and is exemplary of the painstaking and meticulous work that needs to be done in such clinical trials. Ethical standards concerning human subjects are being observed as well as possible.
Other lines of reduction of risk of HIV transmission remain as important as ever: Abstinence, fidelity (particularly, avoidance of multiple concurrent sexual partners), awareness campaigns, condom use, Pre-Exposure Prophylaxis (PrEP), male circumcision, etc. But these are not enough. Some estimate that about 1,000 people are infected with HIV every day in South Africa. The country still requires the largest distribution network of anti-retroviral medication in the world, and uses an estimated ¼ of generic ARV’s worldwide.
Many years ago “AIDS-fatigue” removed the pandemic from news headlines. So, in an often-forgotten battle, it is cheering news that a new vaccine trial is being launched. People living with HIV-AIDS, their families, friends, care-givers, clinicians, scientists, governments and funders all look forward to an “AIDS-free generation.” But I would caution against the kind of media hype we have seen in Africa this week. I do not think that we are on the brink of “the final nail in the coffin for HIV” as the director of the US National Institute for Allergies and Infectious Diseases was quoted as saying. The trial hopes for a 50% reduction in the rate of transmission of the virus in three years. If it does attain that level of success, then 500 people would still be infected each day in my country alone. Certainly, an effective vaccine would be a ‘game-changer.’ But we are looking at decades, rather than years, with the virus and its effects in the lives of tens of millions of people around the globe.