Is the world on the verge of a pandemic? There are three reasons to think so. Two flu viruses are active, and a virus that bears a resemblance to SARS has cropped up in the Middle East. Each has devastating potential, but many early warnings of past pandemics have failed to materialize.
In early 2012, experiments that made H5N1 bird flu more contagious caused an uproar. People feared that mutant viruses could escape the lab and kill people. To prevent a repeat, the government has unveiled a policy describing how scientists should study dangerous pathogens and toxins.