Testing two vaccines against different H1N1s at the same time has never been done.

A pandemic influenza would mean widespread infection essentially throughout every region of the world.

There has been treatment for hepatitis C, but the treatment has not been overwhelmingly effective, number 1. And number 2, it has had considerable toxicity.

You can have an epidemic in a state. You can have it in a region. You can have it in a country where the critical level of disease passes a certain threshold and we call that an epidemic threshold.

Although it is still important to develop an HIV vaccine, we have significant tools already at our disposal that can make a major impact on the trajectory of this epidemic.

What has happened over the years is that scientists have now developed AIDS therapeutic capabilities, as well as prevention, and we've linked prevention and treatment in a way that if you fast-forward 30 years form '88 to now, we can say without hyperbole that we have the tools, if implemented the way they could be implemented, to theoretically, essentially end the epidemic as we know it now.

When you put someone on therapy, you lower the level of virus such that it makes it very difficult for them to infect others.