Uh, little stuff like pepper the entire country, and eventually the world, with anthrax detectors, or make enough vaccine to protect everyone in the US and its allies. What is your personal estimate of how long that would take? You have given this a lot of thought, I take it?
About 50 years. Saddam might not be around by then. We might not be either.
The problem that this brings up is that Iraq (or anybody else with anthrax) will have a strong incentive to use it before their WMD is essentially neutralized. There's a very unstable period while the civil defenses are being developed and installed.
It's just like the worry that construction of an ABM system by Country A would encourage a first strike against Country A before the system is completed, since it's Country B's last chance (and since B would worry that once the system is completed, A could stage a first strike with impunity).
It is very difficult to see a solution to this interim problem.