As the specter of a global flu pandemic looms ever larger, both veteran flu scientists and newcomers to the field are making important progress against the disease. Robert G. Webster, now at St. Jude Children's Research Hospital in Memphis, Tenn., first discovered during the 1960s that the novel flu viruses that seem to sweep through the human population every 30-odd years can arise from combinations of bird and human flu strains. He realized then that preventing new pandemics would require humans to control the avian half of the threat at its source.