After a briefing from his Covid-19 advisory board on the state of the pandemic, president-elect Joe Biden has urged Americans to wear masks to combat transmissions of the coronavirus, fearing a “very dark winter” in coming weeks. The president-elect invoked his message of national unity, telling Americans to put aside partisan disputes as the nation endures growing infections, now topping more than 10 million, with nearly 240,000 deaths. “We can save tens of thousands of lives if we just wear a mask."