Table 1.

Model parameters

Parameters	Symbol	Average value	Range	References
Duration of maternal antibody protection	1/ω	2 months	1–3 months	[21, 22]
Duration of infectious period of 1st, 2nd and subsequent infections	1/γ1,2,3	10, 7, 5 days	–	[23, 24]
Duration of short-term immunity of recovered individuals	1/p	18.7 months (half-life: 7.4 months)	Estimated	[25, 26]
Reduction of infectiousness for 2nd and subsequent infections	ρ1,2	75%, 51%	–	[4, 24, 27–30]
Reduction of susceptibility after 1st, 2nd, and subsequent infections	σ1,2	76%, 60%, 40%	–	[4, 24, 27–30]
Proportion of infections leading to lower respiratory tract infection by age groups	d1,2,3	d1, 0–6 months: 0.5, d1, 7–12 months: 0.4, d1, 13–18 months: 0.3, d1, 19–24 months: 0.2, d1, 2–4 years: 0.15, d1, 5–9 years: 0.15, d1, 10–59 years: 0.1, d1, 60–64 years: 0.15, d1, 65–74 years: 0.25, d1, 75+ years: 0.4 d2 = 0.5 × d1 d3 = 0.25 × d1	–	Adapted from [4, 26, 28, 31]
Seasonality parameters	b,φ	0.141, − 2.831	Estimated
Per contact transmission probability	β0	0.0054	Estimated
Healthcare system use	h	0.396	Estimated