Oral polio vaccine AIDS hypothesis

The Oral polio vaccine AIDS hypothesis (OPV AIDS) is a largely discredited hypothesis which argued the AIDS pandemic originated from live polio vaccines prepared in chimpanzee tissue cultures, accidentally contaminated with simian immunodeficiency virus and then administered to up to one million Africans between 1957 and 1960 in experimental mass vaccination campaigns.

Though a small number of experts initially thought this hypothesis was plausible, later data analyses in molecular biology and phylogenetic studies contradict the OPV AIDS hypothesis.^[1][2][3] Scientific consensus regards the hypothesis as lacking evidence^[1] or disproven.^[4][5] A 2004 Nature article has described the hypothesis as "refuted".^{[6][non-primary source needed]}