Global dynamics of a two-strain flu model with delay

In this paper, we deal with the global dynamics of a two-strain flu model with delay. Using the method of Lyapunov functional, we show that if the basic reproduction number is less than one, then both strains die out; but when the number is larger than one, one or both of the strains become endemic. The main results are confirmed by some numerical simulations. The theoretical results obtained here provide some useful information on the impact of the vaccination rate of a single vaccine for one strain on the dynamics of the two strains.