Tiptoeing Around Pandora's Box.

The avian influenza outbreak in Asia, already one of the worst animal-health disasters in history, has flared up in four countries. In 2000, the U.S. Centers for Disease Control and Prevention in Atlanta, Georgia, started experiments to create crossovers between the H5N1 strain isolated during a 1997 outbreak in Hong Kong and a human flu virus adapted for the lab. The study was suspended when CDC's flu researchers became overwhelmed by SARS and the new H5N1 outbreak, both in 2003, says CDC flu expert Nancy Cox, who led the work. Virologist Albert Osterhaus of Erasmus University in Rotterdam, the Netherlands, is eager to try not just H5N1 but also other bird flu strains, such as H7N7. The studies have been discussed widely with scientists in WHO's global flu lab network and at a recent flu meeting in Lisbon, he says, and have met with nothing but overwhelming agreement.