title: Vaccine-derived polioviruses detected worldwide, July 2009 − March 2011.
mesh_terms: D004196:Disease Outbreaks / Q000517:prevention & control; D014943:Global Health; D006801:Humans; D016867:Immunocompromised Host; D007753:Laboratories; D011051:Poliomyelitis / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D017955:Poliovirus / Q000145:classification; D023321:Poliovirus Vaccines / Q000276:immunology
chemical_list: D023321:Poliovirus Vaccines