` ` The world is a perfect example of vulnerability , '' WHO director Dr. John McCarthy says . Someone could unleash a deadly , genetically engineered microbe that we ca n't fight . Nothing has the potential to kill more people than influenza , he says .
`` The world faces a perfect storm of vulnerability , '' CDC director Dr. Tom Frieden says . Someone could unleash a deadly , genetically modified microbe that we ca n't fight . Nothing has the potential to kill more people than influenza , Frieden says .