The immune systems goal is to protect the body against invaders either from without, such as microbes, or from within, such as cancers and different types of neoplastic transformation.

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.

The launch of phase 1 Ebola vaccine studies is a first step in developing a vaccine that could be licensed and used in the field to protect not only the front line health care workers but also those living in areas where Ebola virus exists.

You help someone's health, and you prevent them from infecting others.

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.

Im generally considered a conservative in my predictions for disease.

The nature of a protective immune response to HIV is still unclear. Because in a very, very unique manner, unlike virtually any other microbe with which we're familiar, the HIV virus has evolved in a way that the immune system finds it very difficult, if not impossible, to deal with the virus.