By mid-January 2021, the U.K., South Africa and Brazil had confirmed that “variants of concern” were driving massive surges in COVID-19 cases in their countries. Once alerted, other nations found these troubling strains rapidly multiplying within their populations as well. At the time, the world had reported 90 million cases, creating abundant opportunities for the coronavirus to mutate. Of those cases, the virus in just 360,000 had been sequenced – and nearly all of them from just a handful of countries.