Table A.1.

Definition of the symbols used in Model (1) and their values used in the examples.

Symbol	Description	Values & range
$k_i$	Rate of progression from $E_i$ to $I_i$, i.e., $1∕k_i$ is the mean latent period	(1/10, 1/7)
${\gamma }_{ai}$	Rate of recovery, i.e., $1∕{\gamma }_{ai}$ is the mean infectious period for $A$ class	(1/10, 1/5)
${\gamma }_i$	Rate of recovery, i.e., $1∕{\gamma }_i$ is the mean infectious period for $I$ class	(1/10, 1/5)
${\mathcal{R}}_{0i}$	Basic reproduction number for group $i$	(1.7, 3.6)
$a_{0i}$	Effective contact rate in the absence of intervention	See Eq. (4)
$a_i\left(t\right)$	Effective contact rate under intervention such as social distancing	See Eq. (5)
${\theta }_i$	Infectivity ratio of $A_i$ to $I_i$ individuals, $0\le {\theta }_i\le 1$	(0.3, 0.6)
${\chi }_i$	Infectivity ratio of $H_i$ to $I_i$ individuals, $0\le {\chi }_i\le 1$	(0, 0.2)
${ϵ}_i$	Level of preference for contacting one’s own group, $0\le {ϵ}_i\le 1$	(0.5, 0.9)
$c_{ij}$	Proportion of contacts a member of group $i$ has with group $j$	See Eq. (3)
${\lambda }_i\left(t\right)$	Force of infection for susceptibles in group $i$ at time $t$	See Eq. (2)
$p_i$	Proportions of infectious that are symptomatic. $p_1\le p_2\le p_3$	(0.4,0.8)
$q_i$	Proportions of disease deaths from the $H$ class	(0.00064, 0.032)
${\varphi }_i$	$1∕{\varphi }_i$ is the mean duration in $H_i$ before disease death	(0.05, 0.1)
${\delta }_i$	Rate of disease death from the $I_i$ class	(0,0.0008)
${\eta }_i$	Rate of moving from the $I_i$ class into the $H_i$ class	(0.2, 0.5)
$T_j$	Time points when a new policy starts. $T_0\le T_1\le T_2\le T_3=T_{end}$	Vary
$s_j^{\left(i\right)}$	Reduction of contacts for group $i$ in time interval $(T_{j-1},T_j]$	Vary
$s_b=s_1^{\left(i\right)}$	Reduction of contacts during the initial restrictions, i.e., in $(T_0,T_1]$	0.8
$s_r$	Reduction of contacts in the residual period $t>T_{end}$	0.2

Note: $i,j=1,2,3$. Time unit is days. Most parameter ranges are based on [1], [16], [19], [28].