President-elect Joe Biden signaled strongly on Monday that fighting the raging pandemic will be the immediate priority of his new administration, an abrupt shift from President Donald Trump’s more unworried approach to the virus, as the nation surpassed 10 million COVID-19 cases. Biden began with a direct appeal to all Americans to wear masks, a departure from Trump, who has mocked Biden and others who make a point of always wearing protective face coverings when around others. In an official move, the president-elect formed a coronavirus advisory board dominated by scientists and doctors, while Trump has had a falling out with the medical experts on his own virus task force.