Fig. 5

Comparison of the risks of unauthorized OPV use by serotype. Serotype comparison of the minimum duration after bOPV cessation or the tOPV-bOPV switch until unauthorized bOPV or tOPV use, respectively, leads to a cVDPV outbreak as a function of the extent of unauthorized use (analysis III). Unauthorized post-cessation RI OPV use proportion represents the proportion of covered children who receive a full schedule of the stopped OPV vaccine. a Population with properties like northern India. b Population with properties like northern Nigeria (y-axis range differ from panel a)