HIV vaccines: The effect of the mode of action on the coexistence of HIV subtypes

We analyze a mathematical model of the simultaneous transmission of two HIV subtypes and their control by vaccines. Two vaccines are analyzed which utilize different mechanisms, one in which the vaccine take differs for each subtype, and the other in which a different level of reduced infectivity results after infection by each subtype. The equilibrium outcome is different for each case; equilibrium coexistence of the two subtypes is possible in the differential take model, but not in the differential reduced infectivity model. This is a first step in understanding the interaction of HIV subtypes and differentially effective vaccines with different modes of action.