It's the advantage of the virus to spread, and you can only spread when you infect people and they infect other people without necessarily killing them. So if you had 100 percent mortality, the potential pandemic would almost self-eliminate itself.

Even the pandemic flu of 1918 only killed one to two percent of the people who were infected.

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

When we can get the incidence of HIV down enough to turn the trajectory of the pandemic, it will assume a momentum of its own in diminishing HIV.

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.

The body's immune system is like any other system of the body. Each of them have their vital function for the human host.