title: Naturally acquired immunity to poliovirus: historical observations have been ignored.
authors.forename: Colin L
authors.initials: CL
authors.lastname: Crawford
mesh_terms: D000349:Africa; D006801:Humans; D007109:Immunity; D011051:Poliomyelitis / Q000453:epidemiology / Q000276:immunology*; D017955:Poliovirus / Q000276:immunology*