Modeling a vaccine against drug-resistance determinants for an endemic colonizing pathogen for which no vaccine currently exists (S.aureus).
a, SIS model with a proportion of the population as vaccinated susceptibles () and as unvaccinated susceptibles (), who can get colonized with either the drug-sensitive ( subscript), or –resistant ( subscript) strain. b, Contour plot of equilibrium stability conditions as a function of vaccine coverage () and specific vaccine efficacy against resistant strain (), for 3 fitness costs. Stability conditions for the resistant-only and sensitive-only equilibrium were obtained analytically and were mutually exclusive. The stable equilibrium state is plotted by color as a function of fitness cost (different panels), vaccine efficacy against the resistant strain (x-axis) and vaccine coverage (y-axis).