Impact of vaccination on the emergence probability of pandemic strains via reassortment.

The average probability of pandemic emergence and its standard deviation (in parenthesis) are obtained from ten million realisations of the dynamics processes within one year period since the introduction of the second endemic strain into a population at endemic with strain 1. Here we consider the special situations where vaccination and primary infection induce the same levels of cross-immunity against endemic and reassortant strains (i.e. φ = ψ = φV = ψV). The values of other model parameters are as in Table 1. The table shows that the levels of cross-immunity heavily control the effectiveness of vaccination while the vaccine coverage plays a much weak role.Impact of vaccination on the emergence probability of pandemic strains via reassortment.