Table 4.

Estimated probability of type 2 transmission die-out (defined as the number of iterations with no ongoing transmission as of December 31, 2026) and the expected value (median) [range] of affected modeled subpopulations out of 720 in 100 stochastic iterations for the scenarios modeled.

	Probability of die out (%)		Estimated expected affected modeled subpopulations (out of 720) (median) [range]
Scenario	IPV in all RI	No IPV prerequisite	IPV in all RI	No IPV prerequisite
mOPV2, current oSIA	34	3	41 (34) [6–138]	102 (105) [10–208]
nOPV2 no reversion, current oSIA	64	51	19 (11) [3–114]	26 (18) [5–179]
nOPV2 some reversion, current oSIA	33	6	41 (34) [8–173]	91 (89) [9–221]
mOPV2, recommended oSIA	89	52	5 (3) [3–30]	23 (17) [4–94]
nOPV2 no reversion, recommended oSIA	100	100	3 (3) [3–17]	5 (4) [4–21]
nOPV2 some reversion, recommended oSIA	93	57	4 (3) [3–39]	17 (9) [4–77]

IPV, inactivated poliovirus vaccine; bOPV2, bivalent Sabin oral poliovirus vaccine; mOPV2, monovalent Sabin oral poliovirus vaccine type 2; nOPV2, novel oral poliovirus vaccine type 2; oSIA, outbreak response supplemental immunization activity; RI, routine immunizations.