Table 2 Model parameters

R ₀

Basic reproduction number

1.4 (range: 1.25−1.8)

[10, 21–24]

δ _p

Reduction in susceptibility of S _p

0−1 (0.48 in simulations)

[11]

δ _a

Reduction in transmissibility of A _s and A _p

0.5

[25]

p _s

Fraction of E _s that become symptomatic

0.6

[25, 26]

p _p

Fraction of E _p that become symptomatic

0.3

Assumption

1/γ _s

Exposed period of E _s

1.5 (days)⁻¹

[27]

1/γ _p

Exposed period of E _p

1.5, 2.6, 4.3, 6 (days)⁻¹

[10]

1/α _s

Infectious period of I _s and A _s

5 (days)⁻¹

[25, 26, 28, 29]

1/α _p

Infectious period of I _p and A _p

varied in simulations

[10]

β

Baseline transmission rate

variable

Estimated from R ₀

expression in (3)