OPV AIDS hypothesis OPV AIDS hypothesis The oral polio vaccine (OPV) AIDS hypothesis posits that the AIDS pandemic originated from live polio vaccines prepared in chimpanzee tissue cultures and then administered to up to one million Africans between 1957 and 1960 in experimental mass vaccination campaigns. Data analyses in molecular biology and phylogenetic studies contradict the OPV AIDS hypothesis; consequently, scientific consensus regards the hypothesis as disproven. The journal "Nature" has described the hypothesis as "refuted". Two vaccines are used throughout the world to combat poliomyelitis. The first polio vaccine, developed by Jonas Salk, is an "inactivated poliovirus vaccine" (IPV), consisting of a
Salk Salk A salk () is a small military unit led by a senior soldier that is subordinate to an infantry squad. "Salk" is bigger than a lahingpaar ("fire and maneuver team") but smaller than a jagu ("squad"). It is also one of the smallest military formation among the Estonian Ground Force infantry units. It usually consists of three to five soldiers, and may be further subdivided into fire and maneuver teams. A "salk" is composed of two fire and maneuver teams of two soldiers each, as well as a fireteam leader ("salgapealik") who is usually a corporal ("kapral"). One single