Fig. 5

Likelihood curves for the two influenza types. a. Type A and b. type B are shown with respect to the number of secondary cases in a household as a function of the force of infection (FOI) coefficient λ₀. The likelihood values are determined by simulation runs with different values of λ₀ and Δλ₀ = 0.005; optimal values of λ₀ are 0.065 for A and 0.015 for B