A new variant of the coronavirus in Great Britain that researchers say spreads 70 percent more effectively is causing Prime Minister Boris Johnson to shutter many parts of the country for Christmas.The new strain of COVID-19 is no deadlier than the original virus, nor does it appear to make people sicker. But it does spread more easily, and that has spooked the British government into basically canceling Christmas.The researchers believe the vaccine developed by Pfizer will still be effective, but scientists are scrambling to confirm that.CNN:According to Whitty, the new variant is responsible for 60% of infections in London, which...