Matt Richtel, a Pulitzer prize-winning technology and science journalist for the N.Y. Times, is the author of “An Elegant Defense.” In this week’s podcast, he reminds us that while we search for the vaccine or the antiviral for the human operating system, we already have one. It’s not made by McAfee or Microsoft, but rather it’s our complex immune system. It’s a system that is both saving us and also killing us.