A medical staff member holds an icebox while simulating to carry the COVID-19 vaccine during a drill...
A medical staff member holds an icebox while simulating to carry the COVID-19 vaccine during a drill days before starting the vaccination process from the Pfizer-BioNTech COVID-19 vaccine, as the coronavirus disease (COVID-19) outbreak continues in Mexico City, Mexico December 18, 2020. REUTERS/Edgard Garrido