THE devastating impact of the new coronavirus variants is becoming clear. The more transmissible B.1.1.7 variant first identified in the UK is causing a surge of infections and deaths around the world. Is this just the beginning? Could even nastier variants evolve? When considering future variants, there are three main properties to worry about: transmissibility, evasion of immunity to past infection or vaccines, and lethality. Of these, transmissibility is the most important. The new coronavirus, SARS-CoV-2, is far less lethal than the Ebola virus, but it has killed far more people because it is much better at spreading. We still…