title: Mycoplasma pneumoniae vaccine: antigenicity of buffered antigens in volunteers.
abstract: The antigenicity of experimental Mycoplasma pneumoniae vaccines prepared from antigen grown in a medium buffered with N-2-hydroxyethylpiperazine-N'-2'-ethanesulfonic acid was tested in young, adult males. Formalin-inactivated antigens from a high-passage strain and a low-passage strain at various dilutions (12 to 123 mug of N/ml) were injected intramuscularly in 1-ml doses. Antibody responses were tested by the metabolic inhibition (MI) technique. Sixty-five to 86% of the volunteers in all vaccine groups responded with fourfold or greater MI antibody rises, but only nine (39%) of 23 antibody-free subjects converted compared to 53 (88%) of 60 of those with pre-existing antibody. A booster vaccination did not increase the number of converters or enhance the geometric mean titers. The antigen concentrations of vaccines with 24 or more mug of N/ml appeared to be above the threshold needed for maximal antibody responses in the dose range tested. MI antibody rises could not be detected in sputa and nasal washings obtained from a small group of vaccinees. The results of this study suggest that the new vaccines offer little or no improvement in antigenicity in man over earlier inactivated vaccines.
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis; D000917:Antibody Formation; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines / Q000009:adverse effects; D002021:Buffers; D005557:Formaldehyde; D006801:Humans; D007114:Immunization / Q000009:adverse effects; D007115:Immunization Schedule; D007273:Injections, Intramuscular; D008297:Male; D009174:Mycoplasma / Q000276:immunology* / Q000378:metabolism; D011014:Pneumonia / Q000276:immunology*; D013183:Sputum / Q000276:immunology; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D002021:Buffers; D005557:Formaldehyde