Dennis J.
O’Callaghan, an American virologist, immunologist and biochemist, died on March 30, 2026. He was born in New Orleans, Louisiana, on July 26, 1940, and earned a B.S.
in biology from Loyola University New Orleans in 1962 and a Ph.D. in microbiology from the University of Mississippi Medical Center in 1968. O’Callaghan was an internationally recognized expert on the molecular biology of the equine herpesviruses. He served on the editorial boards of Virus Research, Virology, Recent Research Developments in Virology and the Journal of Virology, and in the early 1990s patented an antibody protective against EHV-1.
Dennis John O’Callaghan (July 26, 1940 – March 30, 2026) was an American virologist, immunologist and biochemist. He was an internationally recognized expert on the molecular biology of the equine herpesviruses.