How can you believe vaccines work when it has been proved over and over that antibody levels do not = immunity?

I would believe the evidence,unfortunately there isn't any real evidence to say that any vaccines work at all.In order to have real evidence you would have to have done something called a double blind placebo study and these have never been done.Then when you consider the dangers such as the millions and millions of people worldwide who carry cancer causing simian virus 40 from contaminated polio vaccine,then I would say the proven risks from vaccines are obviously greater than the totally unproven benefits.