Humoral immune response in chinchillas to the capsular polysaccharides of Streptococcus pneumoniae.

Vaccines made from the capsular polysaccharides of Streptococcus pneumoniae have been shown to reduce the incidence of pneumococcal disease in certain populations and have recently been evaluated for their ability to elicit protection against experimental pneumococcal otitis media in a chinchilla model. In this study, chinchillas were vaccinated with a dodecavalent preparation of pneumococcal capsular polysaccharides (PCP) to obtain more information on the immunogenicity of these polysaccharide antigens. All 12 PCP types elicited an antibody response, but the optimum PCP dose and the kinetics of the antibody response varied among types. Immunological paralysis was demonstrated with an immunogenic dose of PCP after primary immunization with a large PCP dose (25 micrograms or more). Pertussis vaccine acted as neither an immunoadjuvant nor an immunosuppressant in the serum antibody response to type 7F PCP in chinchillas.