Researchers ponder why covid-19 appears deadlier in the U.S. and Europe than in AsiaTOKYO — It is one of the many mysteries of the coronavirus pandemic: Why has the death toll from covid-19 apparently been lower in Asia than in Western Europe and North America? Even allowing for different testing policies and counting methods, and questions over full disclosure of cases, stark differences in mortality across the world have caught the attention of researchers trying to crack the c
