Researchers hypothesize that a highly contagious strain is spreading; other experts remain skeptical

A research paper from scientists at Los Alamos National Laboratory, not yet peer-reviewed, reports that one strain of the novel coronavirus has emerged in Europe and become dominant around the planet, leading the researchers to believe the virus has mutated to become more contagious The bold hypothesis, however, was immediately met with skepticism by many infectious-disease experts, and there is no scientific consensus that any of the innumerable mutations in the virus so far have changed the general contagiousness or lethality of covid-19, the disease caused by the coronavirus.