>I don't get "testicular swelling" from drinking a beer And this is why population incidence is important: 100K dudes drinking the same beer on the same day at the same time. And assume the population of dudes is evenly distributed by age and race just like the real male population. Out of those 100K, 5-10 will have testicular swelling just naturally from things like prostate cancer or testicular cancer which has nothing at all to do with the beer drinking. This is my point. This is why you need to check population incidence and then use a relevant statistical power test to see if the result is statistically significant compared to the control group (the population). If it is not statistically significant, then it cannot be blamed on the vaccines. We know the answer: it's not the vaccines. It occurs at the same rates in both groups. Same with Bell's Palsy. Same with sterility. And we should know why: the vaccines just don't work in those pathways at all.