Nice essay (by Shannon Brownlee and Jeanne Lenzer, in The Atlantic magazine) on the uncertainty — pro and con — in using a new medicine before there are good studies that reveal whether it is effective:
… All of which leaves open the question of what people should do when faced with a decision about whether to get themselves and their families vaccinated. There is little immediate danger from getting a seasonal flu shot, aside from a sore arm and mild flu-like symptoms. The safety of the swine flu vaccine remains to be seen. In the absence of better evidence, vaccines and antivirals must be viewed as only partial and uncertain defenses against the flu. And they may be mere talismans. By being afraid to do the proper studies now, we may be condemning ourselves to using treatments based on illusion and faith rather than sound science.