He says the scariest recurring nightmare is a global pandemic, triggered by a bio-terror attack, and he's trying to reach out to new National Security Adviser John Bolton about a vaccination plan he believes can prevent it.

Gate doesn't believe a bioattack would prevent all loss of human life, but he thinks a massive vaccination effort could mitigate its catastrophic effects. Gates says the U.S. government is falling short in preparing the nation and the world for the "significant probability of a large and lethal modern-day pandemic occurring in our lifetimes."