title: Relationship of clinical severity, antibody level, and previous vaccination state in smallpox.
mesh_terms: D000906:Antibodies / Q000032:analysis*; D000917:Antibody Formation; D006385:Hemagglutination Inhibition Tests; D006470:Hemorrhage / Q000517:prevention & control; D006801:Humans; D012899:Smallpox / Q000276:immunology / Q000517:prevention & control*; D013997:Time Factors; D014611:Vaccination
chemical_list: D000906:Antibodies