title: Flocculating antigen in the sera of haemorrhagic smallpox cases.
mesh_terms: D000941:Antigens; D006801:Humans; D007106:Immune Sera; D012899:Smallpox / Q000175:diagnosis*; D012901:Variola virus / Q000302:isolation & purification
chemical_list: D000941:Antigens; D007106:Immune Sera