Q. What inspired you to become an HIV/AIDS researcher?
A. I was a medical student at UCSF and then a resident at Beth Israel Hospital, Boston, in the early 1980s, during the initial wave of AIDS. I wanted to do something about it. And now it’s become my life. My wife, Belinda Beresford, covered the spread of AIDS as a journalist in South Africa. In fact that’s how we met. Our blended family includes six children, one of whom lost his biological parents to AIDS.
Q. In 2013, you received $25 million from the Bill and Melinda Gates Foundation. What will that funding enable?
A. The Gates Foundation funding allows my team to move faster through the many scientific and regulatory steps we need to take in order to test a vaccine in humans, and to prepare a final version of the vaccine suitable for widespread use. For now, we can spend less time on grant proposals and more time in the lab.
Q. What’s the status of the preventive vaccine?
A. We now have candidate vaccines that have been engineered to be safe for humans. Next, we will manufacture these vaccines, and test them in formal clinical trials, initially for safety and then for efficacy. We should begin manufacturing next year and hope to initiate a first-inhuman phase I safety trial in 2016.
Q. How is your vaccine different from traditional vaccines?
A. Conventional vaccines educate the immune system to recognize pathogens like HIV more quickly than it would otherwise, but these educated immune responses revert to a resting state shortly after the vaccine is given. When someone encounters the pathogen they have been vaccinated against, their prepared immune system moves faster to prevent or reduce disease. But for HIV and SIV, which replicate very fast and have a unique ability to overwhelm or evade the immune system, even these faster responses are not quick enough.
Our vaccine is different because it persists and therefore keeps the immune system on constant alert. So, whenever the virus enters the body or starts to emerge from a dormant state, the immune system can confront it immediately.
Q. You say your vaccine could lead to a cure for HIV/AIDS – not just prevent it. How would that work?
A. For many years, no one thought it would be possible to get rid of HIV or SIV because they were considered to be permanent infections – the kind that can be suppressed by anti-viral drugs, but never eliminated.
We discovered that our vaccine not only controls the spread of SIV infection in monkeys, but also is capable of clearing all traces of the virus – even the most sensitive tests could not detect any hint of SIV. This remarkable finding prompted us to start thinking in terms of a cure for patients who are living with an established HIV infection. If they are lucky enough to have access to appropriate medical care, these patients can take anti-viral drugs to suppress the infection – but it will emerge if they fail to take their drugs. The virus is never completely gone.
We believe that we have developed a vaccine that will stay in the body for life, continually preventing the virus from emerging and ultimately eliminating it from the body. At some point during this process, the patient will be able to stop taking the anti-viral drugs, because the virus will either be completely gone or reduced to the level where the vaccine ensures the immune system can completely control it.
Q. How does your HIV/AIDS breakthrough accelerate other areas of vaccine research?
A. Everything our team has learned with HIV over the last 12 years can also be used against tuberculosis and malaria – two other diseases that have resisted effective vaccine development and still kill millions around the globe. Our lab has developed a TB vaccine that is already more effective at protecting rhesus monkeys from infection than the most successful vaccine currently in use in humans. The lab’s work on a malaria vaccine is still preliminary, but shows promise.