The only way you can be sure is if it works 100% of the time (which it doesnt). If it fails 50% of the time then how do you know that it worked the other 50% of the time. Could it be possible that many vaccinated people dont get it because they werent exposed?
15-20K people die every year from flu related illness. Does this sound like an effective vaccine?
How do you know if any flu vaccine works?
The only way you can be sure is if it works 100% of the time (which it doesnt). If it fails 50% of the time then how do you know that it worked the other 50% of the time. Could it be possible that many vaccinated people dont get it because they werent exposed?
15-20K people die every year from flu related illness. Does this sound like an effective vaccine?