title: Sera and cerebrospinal fluids from normal uninfected sheep contain a visna virus inhibiting factor.
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism*; D012756:Sheep / Q000276:immunology*; D014790:Visna-maedi virus / Q000276:immunology*
chemical_list: D000998:Antiviral Agents