Computational Modeling of Interventions and Protective Thresholds to Prevent Disease Transmission in Deploying Populations

Table 3

Model parameters for varicella transmission model.

Parameter	Description	Value	Source
𝑏IN	Inward troop rotation rate	Varies over duration of deployment	[3, 16]
𝑏OUT	Outward troop rotation rate	Varies over duration of deployment	[3, 16]
𝛽𝑖𝑖	Effective transmission rate within unit 𝑖	Function of attack rate
𝛽𝑖𝑗	Effective transmission rate between units 𝑖 and 𝑗	Function of attack and contact rates
𝛽𝑖LOCAL	Effective transmission rate between unit 𝑖 and local population	Function of attack rate, contact rate, and local varicella incidence
𝛿𝑆	Proportional reduction in varicella susceptibility after vaccination	97% (50%–100%)	[37]
𝛿𝐼	Proportional reduction in varicella infectivity after vaccination	50% (20%–100%)	[37]
𝜒	Varicella attack rate (soldiers)	50% (30%–90%)	[8, 38]
𝑐𝑖	Contact rate with local population for unit 𝑖	Varies by unit
𝐶𝑖𝑗	Contact rate between unit 𝑖 and unit 𝑗	Varies by unit
incLOCAL	Varicella incidence rate for local population	Varies over duration of deployment	[38–40]
𝜌𝑖	Vaccination rate for unit 𝑖 (90% vaccine efficacy)	Scenario-dependent
𝜇	Background casualty rate for all units	0.0007825 1/day	[16]
1/𝜀	Duration of varicella incubation period	14 days	[37]
1/𝛾	Duration of varicella infectious period	7 days	[37]