@Zardoz @Shadowman311 @ThatWouldBeTelling >to evaluate effectiveness one must also evaluate safety to determine whether harm has occurred. They cannot be separated.
Probably the biggest point that can't really be addressed by the diehard pro-vax crowd, IMO. No control group is possible once mass vaccination occurs. Sometimes the potential risks appear to be worth it, and the challenges inherently present to the calculus do actually affect everyone. Polio vaccine is a good example of this, because it did cause shedding of live polio, a waterborne virus, for something like 6-8 weeks. An uninfected area could suddenly have a vaccination campaign start and result in infected (paralyzed) adults who simply objected or weren't reached in time. Perhaps when we had more social cohesion this was less of an issue, but I also wouldn't blame anyone who resisted a modern vaccine (I refused COVID despite severe employer pressure).