movie title help please

[nonchee]

Hi, I'm new here and really glad to have found my kind of people! I am trying to remember the name of a movie about a plague of some kind and most of the action takes place in a hospital where several people are trapped. The army sends in a cure but there isn't enough for everyone so the "bad" guys use it and it ends up killing them. Ring any bells?

thanks,

nonchee