Mark M. Blatter, MD is Medical Director of Primary Physicians Research. He   graduated from the Medical College of Virginia in 1972 and completed his pediatric training at the Children's Hospital of Pittsburgh in 1975. In 1980, he began doing research on otitis media in childhood under the auspices of Children's Hospital of Pittsburgh's ENT department. In 1986, Primary Physicians Research was created. Initially, the group focused on pediatric trials in the greater Pittsburgh area and was known as Pittsburgh Pediatric Research. Subsequently, as trials involved more diverse areas of medicine including adult as well as pediatric trials and as the geographic area increased to a tri-state area, the name was changed to Primary Physicians Research. Dr. Blatter has worked with a charitable medical group to improve the healthcare of people in the former Soviet Union. He has published numerous articles in such journals as Lancet, Pediatrics, Vaccine, AJDC and Archives of Pediatric and Adolescent Medicine.

Keith S. Reisinger, MD, MPH is Medical Director of Primary Physicians Research. A native of Pittsburgh, Pennsylvania, Dr. Reisinger obtained his medical degree at the University of Pittsburgh. After medical school he received a Master of Public Health at Harvard School of Public Health. He did his pediatric training in Boston at Massachusetts General Hospital and Children's Hospital Medical Center of Boston. Subsequent to his training, Dr. Reisinger spent three years on the Navajo Indian Reservation with the Indian Health Services. After teaching pediatrics at Children's Hospital of Pittsburgh, he entered private pediatric practice. Integral to his practice, he has spent over 20 yeas in clinical investigations and has written numerous publications. Many of these studies have focused on vaccine development including Hib, varicella, mumps, measles, rubella, acellular pertussis and hepatitis B.