of Medicine and a Fellow of the American Association for the Advancement of Science. His publications include work on immune diseases in children and mechanisms of host defense and inflammation. Dr. Johnston is a past president of the society for Pediatric Research and the American Pediatric Society. He is a member of the Board on Health Promotion Disease Prevention of the Institute of Medicine and has chaired four IOM committees, including Multiple Sclerosis: Current Status and Strategies for the Future, the Assessment of Asthma and Indoor Quality, and the Vaccine Safety Committee. He has served on several other IOM committees, including the Committee to review Adverse Consequences of Pertussis and Rubella Vaccines and the Immunology Benchmarking Guidance Group.