Long term persistence of inflammation in children vaccinated with Salmonella conjugate vaccine is associated with augmented Th9-Th17 cytokine

Vaccine induced serum cytokines not only serves as a biomarker of immunity but also serves as a reliable measure of inflammation. Long term persistence of inflammation can lead to metabolic derangement. Towards this end, in the present study, we measured levels of cytokines along with hormones (insulin, leptin and adiponectin) in children who have been vaccinated with Salmonella typhi Vi conjugate vaccine, 30 months after vaccination. Vaccinated children showed a unique cytokine profile with suppressed Th1-Th2 and increased Th9-Th17 cytokines indicating immune polarization which was associated with decreased serum adiponectin (but not insulin or leptin) levels. The study gains major importance since it is a longitudinal study which reports vaccine induced long term persistence of inflammation for the first time in the high risk ethnic population.