Skip Navigation
John Grabenstein

John Grabenstein PhD, COL, USA (Ret.)

Executive Director, Global Health & Medical Affairs, Merck Vaccines
Download vCard

Contact Information



John Grabenstein, PhD, is Senior Medical Director for Adult Vaccines for Merck Vaccines. He provides scientific advice for Merck’s global vaccine enterprise, to reduce the burden of vaccine-preventable diseases worldwide. His duties focus on vaccination initiatives for pneumococcal disease and herpes zoster ("shingles"), vaccines with more than 15 million doses distributed globally each year. A pharmacist with over 30 years experience, he has published over 300 articles and eight books, primarily on immunization, public health, and leadership.

Dr. Grabenstein received his pharmacy degree from Duquesne University in 1980, a master’s degree in education from Boston University in 1988, then his doctorate in epidemiology at the University of North Carolina in 1999.

Previously, as a Colonel in the United States Army, Dr. Grabenstein directed the Military Vaccine Agency, where he oversaw Defense Department immunization programs for 9 million troops, retirees, and family members spread across 4 continents and dozens of ships at sea. In 1996, he wrote the curriculum for "Pharmacy-Based Immunization Delivery," a CDC-recognized 20-hour course coordinated by the American Pharmacists Association (APhA).