Summary
New variants of SARS-CoV-2 are making the world’s fight against COVID-19 even harder. But each of those viruses picks up its crucial changes as it divides in the cells of an infected human being. The nature of those infectionsтАФhow fast the virus replicates and for how longтАФmay determine the odds that they will give rise to new and more troublesome mutants, researchers say. And what they are learning adds weight to the idea that chronic infections and infections that take longer than most to clear may play an important role in the evolution of SARS-CoV-2.
