Scientists who re-created the 1918 Spanish flu say the killer virus was initially a bird flu that learned to infect people. Alarmingly, they find that today's H5N1 bird flu is starting to learn the same tricks. The work involves researchers from the Armed Forces Institute of Pathology (AFIP), the CDC, Mount Sinai School of Medicine, and the U.S. Department of Agriculture. Jeffery K. Taubenberger, MD, PhD, chief of molecular pathology at the AFIP, is one of the study leaders.