Salivary anti-capsular antibodies in infants and children immunised with Streptococcus pneumoniae capsular polysaccharides conjugated to diphtheria or tetanus toxoid

Saliva samples of infants and children immunised with pneumococcal vaccines were analysed for anti-polysaccharide (PS) antibodies against the Streptoc occus pneumoniae (Pnc) vaccine serotypes 6B, 14, 19F, and 23F. The children received Pnc conjugate vaccine (1, 3, or 10 mu g of PSs conjugated to diph theria or tetanus toroid) or placebo at 2, 4, and 6 months. At 7 months of age salivary PS antibodies were detected rarely. All children received Pnc conjugate or PS vaccine at 14 months of age. At 15 months, both IgA and IgG anti-Pnc PS were found, anti-19F and anti-14 antibodies occurring most fre quently and in the highest concentrations. IgA was in the secretory form an d predominantly IgA1. A negative dose dependency was observed in IgA anti-1 9F response. In general, no clear differences in salivary antibody response s were found between the children primed with conjugate vaccine in infancy and those who received their first Pnc vaccine at 14 months of age, suggest ing that priming with Pnc conjugate vaccines does not lead to remarkable mu cosal memory responses. (C) 2000 Elsevier Science Ltd. All rights reserved.