title: Pneumococcal antigen and pneumococcal infection.
mesh_terms: D000368:Aged; D000942:Antigens, Bacterial / Q000032:analysis*; D006801:Humans; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000175:diagnosis*; D013296:Streptococcus pneumoniae / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial