Table. Key parameters of a transmission model for coronavirus disease, Austin, Texas, USA*.

Parameter	Value
Incubation period, d (range)	2.9 (1.9–3.9)
Infectious period, d (range)	6.3 (5.3–7.3)
Asymptomatic proportion, %	43
Average hospitalization, d
Recovered	10.96
Died	8.2
Transmission reduction during Stay Home–Work Safe Order, % (95% CI)†	70 (45%–100%)
Cocooning efficacy, % reduction in transmission relative to Stay–Home Work Safe Order‡
Cocooning	100
Enhanced cocooning	125
Age group, y	0–4	5–17	18–49	50–64	>65
Symptomatic case hospitalization rate, %§
Low-risk group	0.0279	0.0215	1.3215	2.8563	3.3873
High-risk group	0.2791	0.2146	13.2154	28.5634	33.8733
Infected fatality rate, %‡
Low-risk group	0.0009	0.0022	0.0339	0.2520	0.6440
High-risk group	0.0092	0.0218	0.3388	2.5197	6.4402

*Detailed parameter distributions and references are given in Appendix Tables 3, 4.
†Estimated by fitting the model to coronavirus disease hospitalization counts March 13–April 23.
‡The Appendix provides sensitivity analyses with respect to 2 key assumptions of the model: age-specific contact patterns, which might have changed during the recent unprecedented social distancing; and equally effective cocooning of persons at high risk across all age groups. Cocooning and enhanced cocooning are for persons >65 years of age and persons <65 years of age with high-risk underlying conditions. 
§The hospitalization rate and fatality rate for the high-risk group is assumed to be 10 times higher than the corresponding low-risk group in the same age range. The overall hospitalization rate and fatality rate is based on the age-specific values listed in corresponding literature.