Pneumococcal disease is a major health problem worldwide. Large, rapid declines in overall invasive
pneumococcal disease and mucosal disease in children, reductions in
vaccine-type disease in unvaccinated children and adults (indirect effects) and significant drops in
antibiotic-resistant
infections were observed after the introduction of a safe, available and immunogenic seven-valent
pneumococcal vaccine. The determination of
vaccine efficacy is a complex process, which includes efficacy, immunogenicity, safety, cross-reactivity, indirect effects and substantial geographic variation in serotype coverage. In this report, we perform an overview of the literature on current, investigational and potential candidate pneumococcal conjugated
vaccines (PCVs). Every country should have its own strong and sustained surveillance system implemented to monitor the effects of vaccination on the frequency of
vaccine and nonvaccine serotypes for invasive or mucosal
disease, nasopharyngeal carriage and the indirect effects before and after introduction of PCV. New PCVs (PHiD-CV and PCV-13) may provide even greater coverage worldwide, especially in developing countries.
Vaccine experts' efforts are currently focused on developing alternative
vaccine strategies against
pneumococcal infections, especially the development of
vaccines based on pneumococcal
proteins.