The coming of age of niche vaccines? Effect of vaccines on resistance profiles in Streptococcus pneumoniae.

Pneumococcal conjugate vaccine is not only effective against invasive and non-invasive disease in all ages but also has a significant impact on antibiotic-resistant infections since a number of resistant serotypes are targeted by the vaccine. Surveillance studies in the post-licensure years have shown an increase in non-vaccine types both in carriage and disease isolates. There appears to be an increasing trend in antimicrobial resistance among these non-vaccine types, especially in serotype 19A. The impact these non-vaccine types will have on disease remains to be seen, but clearly continued efforts at characterizing the pneumococcal population are essential for future surveillance. Although expanded vaccine formulations with efficacy against a wider range of serotypes will be useful, reduction of drug-resistant Streptococcus pneumoniae will require a combination of the conjugate vaccine and a reduction in antimicrobial use.