evidence: A federal advisory panel voted unanimously Friday to continue to endorse Moderna's Covid-19 vaccine for adults, now that U.S. regulators have given the shots their full approval. The decision has little practical effect. Tens of millions of Americans have already gotten Moderna shots, following its emergency authorization by the Food and Drug Administration more than a year ago. [...] The panel heard summaries of medical studies that showed the vaccine is working against the coronavirus and there is no evidence of new safety concerns.