Short-Sighted Virus Evolution and a Germline Hypothesis for Chronic Viral Infections

Adaptive evolutionary change of viruses within hosts can be detrimental to onward transmission (short-sighted evolution). Loss of transmissibility is likely to be most problematical for rapidly evolving persistent (chronic) viral infections. Within-host viral populations or subpopulations can exhibit lower rates of evolution that expected. Selection probably occurs at the point of transmission, often leading to only one or a few viruses...