TOPSHOT - Nurses lift a Covid-19 patient at the Pasteur hospital resuscitation unit in Colmar, eastern France, on January 22, 2021. - To monitor changes to the coronavirus that could supercharge the pandemic or render vaccines less effective, scientists must sequence its genetic code to catalogue potentially dangerous mutations as they emerge. But so few countries are conducting and sharing surveillance that experts are as worried about the mutations they cannot see as those they can. (Photo by SEBASTIEN BOZON / AFP)