[eno_]

You are too optimistic, especially about anti-virals. Even a large-scale anthrax attack could take out tens of thousands (out of millions exposed). Smallpox would kill millions.

[Trust but Verify]

Smallpox would kill millions where? Good Lord, you'd have to infect, 50 million people to get a mortality in the millions. How are 50 million people going to get infected with anything before quarantines, etc would be put in place.