This project will leverage the surveillance collection of IPD isolates from CMC vellore before and after 2015 uptake in PCV vaccination.

Infections caused by S. pneumoniae affects mainly children less than 5 years of age. Pneumococcal conjugate vaccines (PCVs) are the only preventive measures available. PCV introduced countries has witnessed genetic changes in the population of S. pneumoniae. PCV has been introduced only in 2017 in India, that too only in five major Northern states. To analyse genomic changes in pneumococcal population will require another five years after vaccine introduction. Interestingly, Immunization clinic in CMC, Vellore has introduced vaccine in 2003, and an increase in vaccine uptake was observed after 2016. Thus, doing an analysis of the isolates from CMC, before and after the vaccine introduction will help in early understanding of the effect of PCV in India. Thus, the objective s of the study is to characterize the diversity and evolution of S. pneumoniae serotypes before and after the uptake of PCV vaccination in India. Also, to identify the genetic basis of prevalent antibiotic resistances in these strains.