Table IX.

Model Inputs for the Haiti Outbreak Model

Model input (symbol)	Best estimate	Source	Notes
Number of subpopulations	1		Model Haiti as one population in the absence of good data on heterogeneity
Number of age groups	9		0–2; 3–11 months; 1; 2; 3; 4; 5–9; 10–14; ≥ 15* years
Number of mixing age groups	3		0–4; 5–14; ≥ 15 years
Year when model run-up starts	1950
Year when R0 seasonality starts	1970
Year when die-out first allowed	1980
Average basic reproductive number (R0) (PV1)	9.5		Fitted within range for middle tier (Table III)
Proportional change in R0 due to seasonality ($\alpha$)	0.05	13	Comparatively less seasonality than in temperate climate countries
Day of seasonal peak in R(pd)	180 (June 29)	13	Similar peak day as previously assumed for the Dominican Republic
Proportion of contacts reserved for individuals within the same mixing age group ($\kappa$)	0.3		For simplicity, assume equal values for each mixing age group
Proportion of transmissions via oropharyngeal route ($p^{oro}$)	0.3	19	Based on approximate average of mean expert assessments for community and close contacts for type 1 in high R0 settings(19)
Per-dose take rate for tOPV (tr) (PV1)	0.44a
Routine coverage with 3 or more doses by 1 year of age, birth dose coverage, and partial coverage	Time series 1979–2002	76, 90	See Appendix A4 for values used
Characterization of routine tOPV vaccination, 1979–2002		90
- Doses at birth	1
- Cumulative effect of 3 primary nonbirth doses at ages (months)	3
Characterization of tOPV campaigns 1986–1995			Dates of rounds assumed similar to Cuba; see Appendix A4 for effective per-round impact assumptions by year in the absence of good data
- Day of first round	50 (February 19)
- Day of second round	120 (April 30)
- Duration of each round (days)	7
- Effective per-round impact ($\zeta$)	Varies
- Target age groups	0–4 years
Characterization of tOPV outbreak response, 2001		96, 97	The third round was a rolling campaign that covered children under the age of 10 years over a span of 7 weeks(96)
- Day of first round	28 (January 28)
- Day of second round	63 (March 4)
- Day of third round	140 (May 20)
- Duration of rounds 1 and 2 (days)	7
- Duration of rounds 3 (days)	56
- Effective per-round impact ($\zeta$) of rounds 1 and 2	0.5
-Effective per-round impact ($\zeta$) of round 3	0.9
- Target age groups, rounds 1 and 2	0–4 years
- Target age groups, round 3	0–9 years

Acronyms: PV1 = poliovirus type 1; tOPV = trivalent OPV

^*Age groups marked with an asterisk indicate age groups that count towards determining the fraction of newborns who receive maternal antibodies, based on the immune fraction in those age groups (see Appendix A1).

^aFor runs to verify behavior of other serotypes, we use take rates for tOPV of 0.68 and 0.38 for type 2 and 3, respectively.