The US Centers for Disease Control and Prevention’s annual social media campaign to encourage Americans to prepare for natural disasters and other emergencies usually attracts little more than a yawn. So in 2011, agency communicators tapped into the white-hot popularity of zombies to spice up old-school preparedness advice and create a low-cost campaign that was anything but boring. The campaign quickly went viral, with nearly 5 million people viewing the agency’s zombie apocalypse blog post and media organizations around the world covering the phenomenon. CDC communicators were caught off guard by the campaign’s popularity but made the most of it by developing and implementing a variety of additional strategic communication tactics to extend the campaign’s reach and longevity.