Table 1 Overview of key numerical assumptions of the models used

Relative contribution to transmission compared to fully susceptible, by immunity state^b

[9, 17]

 Maternally immune

0.66;0.48

 1 successful IPV dose, recent

0.74;0.41

 1 successful IPV dose, last waning stage

0.90;0.36

 2 successful IPV doses, recent

0.42;0.06

 2 successful IPV doses, last waning stage

0.81;0.13

  ≥ 3 successful IPV doses, recent

0.28;0.04

  ≥ 3 successful IPV doses, last waning stage

0.72;0.06

 1 LPV infection, recent

0.07;0.05

 1 LPV infection, last waning stage

0.20;0.20

  ≥ 2 LPV infections or IPV and LPV (any # or order), recent

0.01;0.01

  ≥ 2 LPV infections of IPV and LPV (any # or order), lastwaning stage

0.08;0.06

Average time for maternally immune newborns to wane to fully susceptible [months]

3

[9]

Average time for other immunity states to wane from recent to fifth and last waning stage [years]

[9]

 Serotypes 1 and 2

4

 Serotype 3

3

Paralysis-to-infection ratio for WPV^c

[9]

 Serotype 1

1/200

 Serotype 2

1/2000

 Serotype 3

1/1000

Relative R₀ compared to serotype 1 R₀

[9]

 Serotype 2

0.9

 Serotype 3

0.75

Relative R₀ for OPV compared to homotypic WPV

[9, 10]

 Serotype 1

0.37

 Serotype 2

0.55

 Serotype 3

0.25

Average time to reach last of 20 reversion stages (i.e., fully-reverted VDPV, with same properties as homotypic WPV) [years]

[9, 10]

 Serotype 2

1.1

 Serotypes 1 and 3

1.7

Transmission threshold, i.e., minimal prevalence (weighed by contribution to transmission) for non-zero force-of-infection [effective infectious proportion]

5 per million

[9]

Timing of major events

 bOPV introduction for some SIAs

2010

 IPV introduction (in populations using OPV-only in 2013)

2015

 tOPV intensification (until OPV2 cessation)

2015

 OPV2 cessation (in April)

2016

 OPV13 cessation (in April)

2019

 Last year when all populations use IPV

2024

 Last full year of analytical time horizon (T_end)

2052

Average per-dose take rate for OPV^d [%]

[2, 24]

 tOPV, serotype 1

35–65

 tOPV, serotype 2

60–75

 tOPV, serotype 3

27–55

 mOPV, serotype 1

45–90

 mOPV, serotype 2

60–95

 mOPV, serotype 3

45–85

 bOPV, serotype 1

42–80

 bOPV, serotype 3

42–80

Average per-dose take rates for IPV (any serotype)^e [%]

[2]

 Low- and lower-middle income populations

63

 Upper middle-income populations

70

 High-income populations

75

Number of subpopulations with given R₀ for WPV1^f (N = 710)

[2, 7]

 4

20

 5

77

 6

43

 7

250

 8

90

 9

30

 10

30

 11

120

 12

20

 13

30

Number of subpopulations with given proportion of transmissions via oropharyngeal route^g (N = 710)

[2]

 0.3

290

 0.5

40

 0.6

233

 0.8

107

 0.9

40

RI coverage and schedules

Varies^h

[2]

Preventive SIA impact and schedules

Variesⁱ

[2, 5]

Cumulative effective infections needed to trigger a potential exportation from a subpopulation (exportation threshold)

200,000

[2]

iVDPV prevalence

Varies^j

[7]

Average time between contacts of long-term iVDPV excretors with the general population [days]

150–600

[2]

Global rate of WPV and Sabin seed strain releases from randomly determined IPV production sites [per year]

1/5

[2]

Other poliovirus releases (i.e., inadvertent OPV use, unintentional release from laboratory, intentional release)

Varies^k

[2]