Table 1. Parameters for multi-strain dynamics.

Parameter	Description	Unit
β j	Transmission rate of strain j	transmissions/encounter
σ j	Inverse of the latency period of strain j	days−1
γ j	Recovery rate for strain j	days−1
δ j	Rate of immunity loss for strain j	days−1
μ j	Death rate due to strain j	days−1
u(t)	Mitigation (lock-down) effect at time t	-