We are at a time of great promise in the fight against Aids. A few weeks ago at the international Aids conference in Washington, in the United States, the buzz was all about "ending Aids". And it was not just hype.
We are nowhere near the end of the Aids epidemic, but science is pointing us towards the beginning of the end. We have new options for HIV treatment and prevention that need to be made available to many more people. And we have new hope for developing an effective and safe Aids vaccine that could speed up the end of the epidemic.
In less than a decade, South Africa has greatly increased the number of people who receive life-saving HIV treatment, dramatically reduced the number of infants who are infected with HIV at birth and made major contributions to new HIV-prevention research breakthroughs, from voluntary medical male circumcision to antiretroviral-based prevention, including a promising vaginal microbicide and pre-exposure prophylaxis, which involves HIV-negative people taking antiretrovirals (ARVs) to prevent HIV infection.
We still have a long way to go to ensure that new prevention options and treatment are made available to all those who need them, but we are making definite and sustainable progress. We are also making great progress in the search for a vaccine and South Africa is at the heart of the search. Scientists are hard at work in laboratories and clinics and thousands of men and women, and their communities, have participated in clinical trials.
This week in Boston in the US more than 1 000 researchers, advocates and funders from around the world came together to talk about where we are and where we are heading in the development of an Aids vaccine.
Attacking the virus
A few years ago some people had given up hope that we would ever have an Aids vaccine. Scientists were struggling to find new ways to attack the virus, but HIV always seemed to find a way to outwit us. Then, in 2009, a large clinical trial in Thailand showed that a two-vaccine strategy had modest efficacy. It was not enough to lead to the immediate development and distribution of a licensed vaccine, but it provided the proof that it is possible.
Three years on, there is a lot to be excited about. Hundreds of researchers in dozens of labs across the globe sifted through the data, tested and analysed samples from the Thai trial and have begun to unravel why the combination worked and how we might develop a better vaccine.
Over the next three years, South African scientists and communities will begin to test two new strategies. One of those is adapted from the vaccine strategy tested in Thailand and optimised to be more durable and adapted to the strain of the virus that is most common in Southern Africa. We will need thousands more South Africans to volunteer for this trial.
If the vaccine is successful in that trial, it would begin to move towards licensing and eventually into the hands of men and women around the world. We are still some years away from that scenario, but we are hopeful that this strategy might work.
Just in case it does not work, researchers are looking at other vaccine strategies that show promise and are moving the most promising new ideas into the lab and to human trials. One of the most encouraging breakthroughs in the past few years is the discovery of a number of potent, HIV-specific neutralising antibodies. Researchers are working to develop vaccines based on these discoveries.
We are at a crucial point in our response to the epidemic. We need to deliver proven HIV-prevention options such as the prevention of mother-to-child transmission, voluntary medical male circumcision, early ARV treatment and male and female condoms to all those who need them and can use them. We also need to develop pilot programmes to demonstrate how new options such as pre-exposure prophylaxis and eventually, we hope, microbicides, can be most effectively delivered to those who need them most.
If we work to get the proven treatment prevention options we already have to all the men and women who need them, we will start to see the trajectory of new infections turn down. But we will not be able to break the back of the epidemic until we have a vaccine.
South Africa has been a leader in discovering and developing new ways to treat and prevent HIV and in Aids vaccine research. We all have a role to play in finding safe and effective vaccines. Policymakers need to support research with rands and the political will needed to ensure that research programmes do not become bogged down in bureaucracy. And we will need thousands of people to participate in clinical trials with the active support and involvement of their communities and families.
Even a vaccine that is only partially effective could have a major effect on the trajectory of the epidemic if we are able to get it out widely to those who need it. We still have a long way to go, but with the right resources and leadership, support from communities and the participation of volunteers, we can have an Aids vaccine in our lifetime and end this epidemic.
Glenda Gray is the executive director of the perinatal HIV research unit and associate professor of paedia-trics at the University of the Witwatersrand, and co-principal investigator and director of the HIV Vaccine Trials Network's Africa programmes. Mitchell Warren is the executive director of Avac, a global HIV-prevention advocacy organisation based in New York
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