title: A search for the causes of severity in smallpox.
mesh_terms: D000906:Antibodies / Q000032:analysis; D006389:Hemagglutinins, Viral / Q000032:analysis; D006801:Humans; D012899:Smallpox / Q000276:immunology; D012901:Variola virus / Q000472:pathogenicity; D014774:Virulence
chemical_list: D000906:Antibodies; D006389:Hemagglutinins, Viral