Working at a lab with a relatively low level-two biosafety rating, University of Wisconsin-Madison professor Yoshihiro Kawaoka has created a strain of flu that can completely escape the human immune system. Most people today have a level of immunity to the H1N1 flu, which is now regarded as a relatively low threat. Kawaoka genetically manipulated H1N1 so it can "escape" our neutralising antibodies. This would make the human immune system—and population—unable to resist an outbreak.