Tamiflu is an antiviral. There are a couple of other antivirals (relenza) - including some apparently that are off-patent but which have nasty side effects (including psychosis).
If you are science minded - you might try to get your hands on the older drugs. Dunno. Hey... I'd take care not to go too hard on exercise also. 3 times a week seems ok. I do know that people getting into the overtraining area get sick easy.
The following links have heaps of material if you are interested.
http://effectmeasure.blogspot.com (check the tamiflu discussion)
http://www.nature.com/news/2005/0505...l/435399a.html
I don't know. Maybe just maybe if I was in China, I'd wear a mask. I'm not normally into these things but now it seems a rational response.