Flu vaccines are about 60-70% effective. Not all viruses are the same. The flu virus mutates so rapidly it is hard to keep up with the latest strains since this virus jumps the species barrier so readily. Try not to get taken in by the Luddites. Snake oil has been selling for centuries and there is always a market for it.
In which case, a double blind study with a large enough sample size should clearly reveal that. Trouble is, they don't study that simple result.
Take, for example, this study:
Comparative Efficacy of Inactivated and Live Attenuated Influenza Vaccines (NEJM, 24 Sep 2009)
The results they reported are here:
You will note that they didn't have a control group (a group that received neither the placebo nor one of the vaccines). So how the hell can they say it's a valid study?
Next, where's the study showing the effect of living healthy (actually getting the right number of antioxidant vitamins, proper mineral balance, lifestyle choices) versus taking a vaccine? I've NEVER seen such a study. With or without a control group.
Bottom line is that I want to see independent studies. I'm not condemning this stuff out-of-hand, but there seem to be too many hands in too many pockets and too much fishiness.