Fig. 2

Two contrasting examples of serotype 1 and 2 immunodeficiency-associated vaccine-derived poliovirus (iVDPV1 and iVDPV2, respectively) outbreaks with various outbreak response vaccine choices for subpopulations that share a block with subpopulations that detected a case , including a ring with inactivated poliovirus vaccine (IPV), showing the incidence in the block of the initial outbreak. a Outbreak following an iVDPV2 introduction in a block with a basic reproduction number (R₀) of 10, resulting in a serotype 2 monovalent oral poliovirus vaccine (mOPV2) exportation outbreak in another block for the strategy that responds only in subpopulations with detected virus using mOPV2. b Outbreak following an iVDPV1 introduction in a block with an R₀ of 11, resulting in a new iVDPV1 excretor and virus reintroduced for the strategy of serotype 1 monovalent oral poliovirus vaccine (mOPV1) in the entire block