The protective level of serum antibodies to the capsular polysaccharide of Haemophilus influenzae type b.
D000907:Antibodies, Bacterial / Q000032:analysis*; D001428:Bacterial Vaccines / Q000276:immunology*; D006193:Haemophilus influenzae / Q000276:immunology*; D006801:Humans; D011135:Polysaccharides, Bacterial / Q000276:immunology*
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D011135:Polysaccharides, Bacterial