The impact of quasispecies dynamics on the use of therapeutics.

The application of quasispecies theory to viral populations has boosted our understanding of how endogenous and exogenous features condition their adaptation. Mounting empirical evidence demonstrates that internal interactions within mutant spectra may cause unexpected responses to antiviral treatments. In this scenario, increased mutagenesis could be efficient at low mutagen doses due to the lethal action of defective genomes, whereas sequential administration of antiviral drugs might be superior to combination therapies. Our ability to predict the outcome of a particular therapy takes advantage of the complementary use of in vivo observations, in vitro experiments, and mathematical models.