Vaccination Drives Changes in Metabolic and Virulence Profiles of Streptococcus pneumoniae

The bacterial pathogen,streptococcus pneumoniae (the pneumococcus),is a leading cause of life-threatening illness and death worldwide. available conjugate vaccines target only a small subset (up to 13) of >90 known capsular serotypes of s. pneumoniae and,since their introduction,increases in non-vaccine serotypes have been recorded in several countries: a phenomenon termed vaccine induced serotype replacement (visr). here,using a combination of mathematical modelling and whole genome analysis,we show that targeting particular serotypes through vaccination can also cause their metabolic and virulence-associated components to transfer through recombination to non-vaccine serotypes: a phenomenon we term vaccine-induced metabolic shift (vims). our results provide a novel explanation for changes observed in the population structure of the pneumococcus following vaccination,and have important implications for strain-targeted vaccination in a range of infectious disease systems. © 2015 watkins et al.