WHO expert consultation on serotype composition of pneumococcal conjugate vaccines for use in resource-poor developing countries, 26-27 October 2006, Geneva.

Pneumococcal conjugate vaccines induce serotype specific protection, with cross-protection seen between serotypes within certain serogroups. Though most serious pneumococcal infections are caused by relatively small number of serotypes, choices need to be made on the serotypes to be included in the vaccine because of the complexity and cost related to developing and producing vaccines with increasing number of serotypes. The choice is rendered difficult because of differences in the distribution of serotypes causing serious disease between different geographic regions and age groups as well as changes over time. The World Health Organization convened an expert consultation to formulate a data-driven approach to determine the minimum or optimal formulation of pneumococcal conjugate vaccines, particularly keeping in mind the needs of developing countries as well as the epidemiologic, regulatory, formulation and manufacturing issues involved. The deliberations and conclusions of this meeting are summarized in this report.