Matthew Oetgen, MD, MBA

Marc DiFazio, M.D., is the Vice President ofambulatory Services at Children’s National Hospital. He completed his pediatric and neurology training at Walter Reed Army Medical Center, and went on to become the Chief of Child Neurology at Walter Reed, where he served on active duty until 2005 before transitioning to private practice in Rockville, MD.

Michael Keller, M.D., is a pediatric immunologist at Children's National Hospital and specializes in the diagnosis and treatment of primary and secondary immunodeficiency disorders. He is the Director of the Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiency Disorders. He has authored many peer-reviewed articles and contributed to expert consensus guidelines on the treatment and diagnosis of primary immunodeficiency disorders. Dr. Keller is a member of theamerican Academy of Allergy, Asthma, and Immunology (AAAAI); the Clinical Immunology Society; the European Society of Immunodeficiency; and the Primary Immunodeficiency Treatment Consortium (PIDTC).

George Zalzal, M.D., is professor of Otolaryngology and Pediatrics with tenure at the George Washington University and emeritus chief of the Division of Pediatric Otolaryngology at Children’s National Hospital in Washington, D.C.