Despite widespread utilization of pneumococcal conjugate vaccines (PCVs) and the resultant disease reduction, the development of PCVs containing additional serotypes remains a public health priority due to serotype replacement and the resultant shift to non-vaccine containing serotypes. However, incorporating additional serotypes to existing PCVs using conventional technologies has proven problematic. Immune responses to individual serotypes have consistently decreased as more polysaccharide-conjugates are added due to carrier suppression.
View Article and Find Full Text PDFClin Vaccine Immunol
October 2011
Lot 89SF has been the reference standard serum pool used in pneumococcal enzyme-linked immunosorbent assays (ELISAs) since 1990. In 2005, it was estimated that there remained between 2 and 5 years' supply of lot 89SF. Since lot 89SF was the reference standard used in the evaluation of the seven-valent pneumococcal conjugate vaccine Prevnar (PCV7), the link to clinical efficacy would be severed if stocks became completely depleted.
View Article and Find Full Text PDFThe introduction of a 7-valent pneumococcal conjugate vaccine (PCV7) in 2000 dramatically reduced the incidence of invasive pneumococcal disease (IPD) caused by the seven serotypes covered by the vaccine. Following the introduction of PCV7, which contains a serotype 6B conjugate, some decrease in IPD due to serotype 6A was noted suggesting that the serotype 6B conjugate provided some partial cross-protection against serotype 6A. However, no effect on serotype 6C was observed.
View Article and Find Full Text PDFHealthy adults aged ≥ 70 years (N=443) with no history of pneumococcal vaccination received 7- or 9-valent pneumococcal conjugate vaccine (PCV7 or PCV9) at 1 × (PCV7 only), 2 × (PCV7+PCV9), or 4 × (2 × PCV7+2 × PCV9) dosage in a randomised, open-label study evaluating pneumococcal protein conjugate vaccine (PnC). Controls received 23-valent pneumococcal polysaccharide vaccine (PPV). Both geometric mean concentration enzyme-linked immunosorbent assay and opsonophagocytic activity antibody titres assessed 1 month after vaccination were significantly increased over baseline titres for all PCV7 serotypes, with a trend toward a dose-dependent immune response.
View Article and Find Full Text PDFStreptococcus pneumoniae and Neisseria meningitidis cause invasive disease in children aged <2 years. While individual conjugate vaccines are available to protect this age group against these pathogens, availability of a vaccine combining these antigens into a single injection is desirable. This study randomized 467 healthy infants to receive 4 doses of combination 9-valent pneumococcal and meningococcal serogroup C conjugate vaccine (9vPnC-MnCC) or 9-valent pneumococcal conjugate vaccine (9vPnC).
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