Complex sentence: Messenger organized a 2015 lecture tour of Australia for fellow anti-vaxer Sherri Tenpenny which was cancelled due to public outcry over her views on vaccination which go against established scientific consensus.
Split into simpler sentences: Messenger organized a 2015 lecture tour of Australia for fellow anti-vaxer Sherri Tenpenny. The tour was cancelled due to public outcry over the anti-vaccination stance of the tour, which ran counter to established scientific consensus.