With Ebola ravaging West Africa, and flu season quickly approaching, I can’t help but think about infectious diseases and how I will survive. In troubled times like these, I turn to movies for reassurance. No, I’m not talking about watching Outbreak and realizing that saving the world from an airborne Ebola-like pandemic is as simple as catching a monkey in the suburbs, or watching Steven Soderbergh’s Contagion and realizing that bats and pigs (and Gwyneth Paltrow) are the worst biological enemies known to man. Instead, I look to more traditional science fiction and realize that while diseases lay waste to large segments of the human population, they may also be our saving grace from alien invasion. After all, that’s the plan that H.G. Wells laid out in “War of the Worlds,” which was adapted into films in 1953 and 2005. While Wells (along with George Pal and later Steven Spielberg) warned us of potential dangers from life on other planets, he also assured us that our own microbes might keep us safe from atmospheric intruders. After all, it was these microscopic organisms that disabled and eventually wiped out the invading Martians. And that got me thinking: Could the microbes here on Earth save us from an alien invasion?