Fig. 1.

Schematic representation of direct, indirect, total and overall effect in two populations (modified from Halloran 2011) Direct effect was calculated as 1– (VT carriage rate in children who received all three doses /VT carriage rate in children who received zero dose), indirect effect was defined as 1- (VT carriage rate in children who received zero dose /26.7%), total effect was defined as 1-(VT carriage rate in children who received all three doses/26.7%) and overall effect was defined as 1- (carriage rate in the study population / 26.7%).