Good example. Pan and others are very busy re-writing the actual history of vaccines, diseases and exemptions in the US and probably in other countries too. With an abject news media, they've got a free hand, alas.@applejuice can explain the history of exemptions in Wisconsin, where a woman's child had an adverse reaction, and she successfully lobbied for non-medical exemptions. I suspect that Wisconsin is not unique in having its vaccine policies influenced by concerns for choice and safety.