Yes, I would, Madam Chair.
I will just illustrate to the committee how rapidly things change. The failure of one vaccine trial, the so-called STEP trial--I believe it was announced in 2008--cast a tremendous pall over the whole field of HIV vaccines. The vaccine that people thought was the best possible candidate actually probably increased the risk of people becoming HIV-infected, and it was a tremendous disappointment. But late last year there was a very encouraging result from Thailand that showed that a vaccine that nobody expected would work actually provided significant protection for a relatively short period of time.
So the field changes dramatically in relatively short periods of time and you have to be prepared to adapt to that.