Table 1.

Description of state variables of between-host and within-host COVID-19 model.

Variables	Description
$H_S$	Susceptible human
$H_E$	Exposed human
$H_I$	Infectious human
$H_Q$	Quarantined human
$H_R$	Recovered human
$V$	Average viral load within a single infected human
$E_S$	Susceptible epithelial cells
$E_L$	Latently infected epithelial cells
$E_I$	Infectious epithelial cells
$K$	Killer T-cells
$B$	B-cells
$T$	Cytotoxic T-cells