  The aim of this work is to investigate the optimal vaccine sharing between
two SIR centers in the presence of migration fluxes of susceptibles and
infected individuals during the mumps outbreak. Optimality of the vaccine
allocation means the minimization of the total number of lost working days
during the whole period of epidemic outbreak $[0,t_f]$, which can be described
by the functional $Q=\int_0^{t_f}I(t){\rm d}t$ where $I(t)$ stands for the
number of infectives at time $t$. We explain the behavior of the optimal
allocation, which depends on the model parameters and the amount of available
vaccine.
