Mutation takes no vacation: Can structured treatment interruptions increase the risk of drug-resistant HIV-1?

We use a mathematical model to study the dynamics of HIV-1 replication duri ng structured treatment interruptions (STIs) in infected patients. The mode l predicts rapid viral rebound, restoration of a latently infected cell poo l, and critically, partially resistant mutant rebound that may be missed be cause of high levels of wild type virus. Because partially resistant viruse s are capable of mutating to full resistance, a substantial increase in the ir numbers represents a threat to therapeutic response durability. Compared with continued treatment, STIs may increase the chance of mutation to full resistance by several thousandfold.