Anti-Vaccination Movement

Anti-vaccination misinformation kills more than any pseudoscience on this list. Wakefield's 1998 study, which fraudulently linked MMR vaccines to autism, has been retracted by The Lancet and rejected by 25 subsequent large-scale studies involving over 10 million children. Yet this debunked claim has driven vaccine coverage below the 95% herd immunity threshold in 15 countries, causing measles cases to surge 400% globally since 2016. Concrete data from the WHO shows vaccination prevents 2.5 million deaths annually; every percentage-point drop in coverage directly correlates with preventable outbreaks. The movement's persistence, fueled by algorithms amplifying fear, makes it the most deadly pseudoscience practice today.