More than 156 million people in the U.S. have been fully vaccinated. But even though the Covid-19 vaccines are very effective against all the known coronavirus variants, including the highly transmissible delta variant that is spreading rapidly, some communities and physicians are urging a return to masking. [cut] Dr. Andy Dunn, a family physician and chief of staff at Wyoming Medical Center in Casper, wants vaccinated people to continue with masking. "These variants are going to find a way" to survive, Dunn said. "Do whatever it takes for Covid to go away," he added. "If I had to jump on...