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.
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 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.
Some of the most vulnerable people to getting the SARS virus are health care providers. The general public, walking in the street, there is really not that much risk at all. It's a very, very low risk - a very, very low risk.
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.
I think it would be over-exaggeration to think that there are millions of viruses ready to jump on us and bring us back to the 14th century. That would be looking over a ledge that isn't there.
In the early days, a Georgia college kid named Chris Putnam created a virus that made your Facebook profile resemble MySpace, then the social-media incumbent. It went rampant and started deleting user data as well. Instead of siccing the F.B.I. dogs on Putnam, Facebook co-founder Dustin Moskovitz invited him for an interview and offered him a job.
I was less successful in my attempts to effect preventive vaccination against typhus by using the virus and in trying to produce large quantities of serum using large animals.
Just as the only reservoir for the typhus virus in nature is provided by man, so the only vector of infection is the louse. The bite of the louse is not virulent immediately after the infecting meal. It becomes so only towards the 7th day following infection.
The discovery that I soon made that the guinea pig was also susceptible to infection made it possible for me, from the third year on, to preserve the virus on this animal.
