Pfizer and BioNTech announced their coronavirus vaccine was more than 90% effective in preventing Covid-19 among those without evidence of prior infection, hailing the development as “a great day for science and humanity.” CNBC’s Meg Tirrell discusses her earlier conversation with Pfizer Chairman and CEO Dr. Albert Bourla. Meanwhile, the United States has reported more than 10 million cases of Covid-19, a bleak milestone amid growing outbreaks across the country. President-elect Joe Biden urged Americans to wear a mask to help the country bring the coronavirus pandemic under control, to save lives and to enable communities to reopen schools and businesses. Plus, Georgia is about to become the center of the political universe as control of the Senate is likely to come down to the Jan. 5th Georgia runoff.