Alfred Blalock (April 5, 1899 – September 15, 1964) was an American surgeon most noted for his work on the medical condition of shock as well as tetralogy of Fallot – commonly known as blue baby syndrome. He created, with assistance from his research and laboratory assistant Vivien Thomas and pediatric cardiologist Helen Taussig, the Blalock–Thomas–Taussig shunt, a surgical procedure to relieve the cyanosis from tetralogy of Fallot. This operation ushered in the modern era of neonatal cardiac surgery. He worked at both Vanderbilt University and Johns Hopkins University, where he studied medicine and later served as chief of surgery. He is known as a medical pioneer who won various awards, including Albert Lasker Clinical Medical Research Award. Blalock was also nominated several times for the Nobel Prize in Medicine.