An empty gurney is seen outside of a hospital's morgue in Baltimore, Maryland on December 23, 2020 during the Covid-19 pandemic. - The United States surpassed 18 million reported Covid-19 cases on Monday, figures from Johns Hopkins University showed, as the virus surges nationwide. States and cities have imposed varying levels of restrictions in a bid to slow the virus spread, but outgoing President Donald Trump has repeatedly downplayed its seriousness and urged reopenings. (Photo by Andrew CABALLERO-REYNOLDS / AFP)