Table 1.

High R₀ and/or low RI coverage blocks, characteristics, reported and modeled expected cVDPV2 since OPV2 cessation (as of April 25, 2023) and modeled expected cVDPV2 cases for the 2022–2026 time horizon

Block	IL	Name	R0	Lowest RI coverage in the block	Reported cVDPV2 cases between May 1, 2016-December 31, 2022*	Modeled expected cVDPV2 cases since OPV2 cessation+			Modeled expected cVDPV2 cases 2022–2026
						mOPV2	best nOPV2	worst nOPV2	mOPV2	best nOPV2	worst nOPV2
All Blocks (global)
1–72					2973	3374	3279	3393	17,138	6,438	22,240
High R0 (≥10) and low RI coverage (≤0.3) blocks
1	LI	Central Africa 1	10	0.3	630	310	307	328	2,908	2,116	3,602
2	LI	East Africa 1	11	0.3	61	108	98	108	1,580	423	1,585
3	LI	East Africa 2	10	0.3	-90	267	260	261	1,134	155	2,997
5	LI	West Africa 1	11	0.3	450	418	409	420	1,419	191	1,885
32	LI	North Pakistan and Afghanistan 1	11	0.3	461	522	523	523	96	496	181
34	LMI	Rest of Pakistan 1	11	0.3	56	124	125	127	201	149	292
47	LMI	India 1	13	0.3	0	0	0	0	477	86	585
48	LMI	India 2	13	0.3	0	0	0	0	466	66	491
High R0 (R0≥10) blocks
49	LMI	India 3	12	0.9	0	0	0	0	367	68	272
50	LMI	India 4	11	0.9	0	3	2	3	276	49	272
51	LMI	India 5	11	0.9	0	0	0	0	227	58	286
52	LMI	India 6	11	0.9	0	0	0	0	223	57	226
53	LMI	India 7	11	0.9	0	0	0	0	330	25	211
54	LMI	India 8	11	0.9	0	0	0	0	299	31	283
55	LMI	India 9	11	0.9	0	0	0	1	273	62	329
56	LMI	India 10	11	0.9	0	5	7	6	314	67	267
57	LMI	India 11	10	0.9	0	0	0	0	321	32	307
58	LMI	India 12	10	0.9	0	0	0	0	201	64	180
68	LMI	South Asia 1	12	0.6	0	0	0	0	124	0	206
69	LMI	South Asia 2	13	0.6	0	2	0	0	118	20	141
Low RI coverage (≤0.3) blocks
7	LMI	Middle-income Africa-Arabia 1	8	0.3	375	729	734	786	746	615	1,107
8	LMI	North Nigeria 1	8	0.1	524	509	509	511	202	249	327
9	LMI	West Africa 2	9	0.3	13	13	13	13	835	276	1,378
13	LMI	South Asia 3	8	0.3	1	1	1	1	18	45	72
36	UMI	Mid-east 2	7	0.05	74	73	73	73	105	83	101
38	LMI	Eurasia 2	7	0.3	2	0	0	0	1	1	1
Other blocks (not High R0 (≥10) or low RI coverage (≤0.3))
			<10	>0.3	236	291	216	231	3,879	953	4,655

Notes:

^*Reported cases after OPV2 cessation (for the period May 1, 2016 to December 31, 2022 as of April 25, 2023,

⁺Modeled expected cases for the same period as reported

Abbreviations: cVDPV2, type 2 circulating vaccine-derived polioviruses; IL, income level; mOPV2, type 2 monovalent OPV; nOPV2, type 2 novel OPV; OPV, type oral poliovirus vaccine; R₀, basic reproduction number; RI, routine immunization