Derrick T. Vail was born on October 2, 1864 in Franklin, Ohio. After graduating from Miami Medical College in 1890, he practiced ophthalmology in Cincinnati, Ohio. His discovery of Tularemia-Conjunctivitis in man with Dr. William B. Wherry was his major contribution to medicine.

Dr. Vail married Dellah Harris of Franklin, Ohio, on April 14, 1891. The couple lived at 2219 Park Avenue, Walnut Hills, in Cincinnati, Ohio.

Their daughter Charlotte Farrell Vail attended Smith College with the Class of 1923. She died in Northampton, Massachusetts, on March 11, 1923. Dr. Vail died on October 29, 1930. Mrs. Vail died on December 7, 1935. They were survived by their daughter Rosalind Vail Dwight of Cincinnati, Ohio.