It's extremely likely that the people who have never been exposed to a human who has leprosy, it's very likely they got leprosy from exposure to an armadillo.

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.

For the first time, we have the genetic sequences of all three of the players in the global malaria debacle: the parasite, the anopheles mosquito and the human. It's a very important milestone.

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

The difference between H7N9 and H5N1, is that H5N1 kills chickens very rapidly, so it is easy to identify where the infected flocks of chickens are. H7N9 doesn't make the chicken sick, so it has been difficult to pinpoint where the infected chickens are.

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