sentences:  He served as the director of clinical studies for the Vaccine Research Group from 1989 to 2014 where the worked focused on vaccine immunogenicity and the genetics of vaccine response, especially towards measles, mumps and rubella as well as vaccines directed against bioterrorism including anthrax and smallpox vaccines.In 2000, he became the interim chair of the Department of Pediatric and Adolescent Medicine which includes the Mayo Eugenio Litta Children's Hospital and then in 2001 became the definitive chair.In 2010, he completed his term chair of the department to lead the Employee and Community Health (ECH) Research Initiative, which focuses on population-based interventions to improve patients' health.