Dr. Ali S. Khan is the former director of the Office of Public Health Preparedness and Response (PHPR) at the centres for Disease Control and Prevention. In more than 20 years at the CDC, his professional career has focused on emerging infectious diseases, bioterrorism, and global health security. In that position, he oversaw the national public health-security program with a 1.3 billion budget and 600 employees. The office is responsible for protecting US communities from all public-health threats. Now dean of the College of Public Health at the University of Nebraska, he lives in Omaha with his family.