Is an Engineered Pandemic Possible?

A 2011 experiment to increase the transmissibility of avian flu, H5N1, in mammals was controversial and triggered a review by the National Science Advisory Board for biosecurity. A purposefully engineered pandemic pathogen does have the potential to be significantly more deadly and spreadable. How likely we are to face such a pathogen is a matter of debate but over the next century, the likelihood doesn't seem negligible. The median expert estimated that there was a 10% chance of 1 billion people dying in an engineered pandemic before 2100.