I'm intrigued by the claim being made by scientists studying the SARS epidemic that different patients have wildly different infectivities. I would guess (ridiculously naively, I admit) that SARS isn't unique in that regard. It might, then, be worth looking into an alternative approach to dealing with epidemics that focuses on curtailing infectivity rather than infection.
Suppose, for instance, that there were an (otherwise pretty harmless) drug that neither prevented nor cured any particular disease, but did drastically reduce the infectivity of people with a particular highly infectious disease. Mass distribution of such a drug might then be an effective way to combat an epidemic of that disease. It might be as simple as, say, an anti-expectorant that reduced the output of virus-laden droplets from a SARS patient's respiratory tract.
I hope somebody in the public health field is looking into this approach--if only to refute it as unworkable.