It's to keep our supply up.
Smallpox is interesting. There's a first-generation smallpox vaccine, which is good for everybody; about 3% of the population is not able to take that. We also have a smallpox immunoglobulin for folks who get exposed, and then a third-generation vaccine. We were just talking about it. They don't last forever, so they have to be turned over, and the old supply has to be replaced.