Meningococcal infection: serological studies.
D000907:Antibodies, Bacterial; D004739:England; D006801:Humans; D008585:Meningitis, Meningococcal / Q000276:immunology; D008589:Meningococcal Infections / Q000276:immunology*; D014481:United States; D014852:Wales
D000907:Antibodies, Bacterial