Flu vaccine: the moral/ethical dimension

I'm pretty sure the swine flu is "real" at this point (whether it is natural or nefariously introduced by a conspiracy is of little importance for the purposes of this thread).

But I also have grave doubts about the vaccine for obvious reasons...the untested nature of it, the political aspects, all the stuff ATS has been hashing out for months lately.

The problem is this: If you come down hard on the "pro-vaccine" side and turn out to be wrong, you could be contributing to lots of innocent deaths. If you come down hard on the "anti-vaccine side" and turn out to be wrong, you could also be contributing to lots of innocent deaths.

Whenever any of us speaks with conviction on this topic to friends or relatives, or writes messages on the Internet, we are making a moral and ethical stand, whether we realize it or not. A risky one, too, because in the end we are talking real human life and health here.

How do you justify your certainty (or uncertainty) regarding this issue?