41.   The same is true for drugs of course, but medicines are given to sick people while vaccines are given to healthy people.

42.   The vaccine must be given within a few days after exposure to smallpox, posing a logistical nightmare if outbreaks were to occur in several locations simultaneously.

43.   The vaccine also is given to civilians who work with animals.

44.   The vaccine is not given to women who are known to be pregnant, because it is made with a living though weakened virus.

45.   Though soldiers were once given a vaccine against the adenovirus, there is no proven treatment now in use.

46.   Vaccines are typically given one to five times over a lifetime.

47.   Health and Human Services Secretary Tommy Thompson will decide whether to give the vaccine to those exposed to the bacteria and considered most at risk of developing the disease.

48.   The vaccine cannot be given to children younger than one.