...After nearly a decade of research, teams of scientists said yesterday that they had re-created the historic influenza virus that by some estimates killed 50 million people world-wide in 1918 and 1919. The scientists concluded that the virus originated as an avian bug and then adapted and spread in humans by undergoing much simpler changes than many experts had previously thought were needed for a pandemic. Some mutations of the 1918 virus have been detected in the current avian-flu virus, suggesting the bug "might be going down a similar path that led to 1918,".... The studies, published yesterday in the...