As coronavirus infections surged around the country in early November — and as the prospect of a long, dark winter loomed — it was not clear if any of the vaccines in development would pan out. Now, three months later, the picture is very different. Two highly effective Covid vaccines are rolling out around the country. Three others appear to be slightly less robust, but still offer strong, and in some cases complete, protection against severe disease and death. In the past week alone, Novavax and Johnson & Johnson reported that their vaccines offered good protection, including against new, more contagious variants of the coronavirus. And a new analysis from the University of Oxford suggests its vaccine, developed with AstraZeneca, has the potential to slow transmission and works especially well when second doses are delayed. After a sputtering launch, vaccination in the United States is speeding up: More than […]