Validation of a routine opsonophagocytosis assay to predict invasive pneumococcal disease efficacy of conjugate vaccine in children.

Immunological evaluation of the clinical impact of vaccines designed to protect against infection by Streptococcus pneumoniae requires measurement of serotype-specific functional antibodies. We describe the development and validation of a viable pneumococcal opsonophagocytosis assay (OPA) that can be used for routine serological analysis of paediatric immune responses after immunization. OPA seropositivity (%> or =8 threshold) reflected well invasive pneumococcal disease (IPD) effectiveness.

Diphtheria-tetanus-pertussis (DTP) combination vaccines and evaluation of pertussis immune responses.

Diphtheria-tetanus-pertussis (DTP) combination vaccines based on inactivated whole-cell Bordetella pertussis (DTPw) or purified acellular pertussis components (DTPa) facilitate vaccine administration and will allow further co-administration such as with pneumococcal conjugates. Safety and immunogenicity studies are needed to demonstrate non-inferiority between combinations and the separate vaccines. The immunological non-inferiority is based on threshold antibody levels that represent correlates of protection.