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.

Staph lives on skin. Thats the reason why many infections start as a boil.

An AIDS-free generation would mean that virtually no child is born with HIV; that, as those children grow up, their risk of becoming infected is far lower than it is today; and that those who become infected can access treatment to help prevent them from developing AIDS and from passing the virus on to others.

When I was a child, there were not that many vaccines. I was vaccinated for polio. I actually got measles as a child. I got pertussis, whooping cough. I remember that very well.

When a company is fairly certain of a profit margin that is substantial, it can assume responsibility for the clinical trials to develop a blockbuster drug.

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.

Investigating rare diseases gives researchers more clues about how the healthy immune system functions.