Sir Michael Anthony Epstein was born in London on 18 May 1921 and educated at St Paul's School, London. He attended Trinity College, Cambridge, where he earned his BA in 1943, followed by an MB BChir in 1949, an MA (Cantab.) that same year, and an MD in 1951. He undertook his medical training at Middlesex Hospital Medical School, University of London. He obtained his PhD in 1952 and DSc in 1963 from the University of London, as well as an MA (Oxon.) from the University of Oxford in 1987.
Sir Anthony's first appointments were in surgery at the Middlesex Hospital and at Addenbrooke's Hospital, Cambridge in 1944, but he moved into laboratory-based medicine after his two-year service in the Royal Army Medical Corps, during which he fought in Burma and attained the rank of Captain. In 1948, he returned to the Middlesex Hospital as Assistant Pathologist at its Bland-Sutton Institute (BSI), a position he held until 1965. While working at BSI, he travelled to France and the United States, developing collaborations with Pierre Lépine at the Institut Pasteur and George Palade at the Rockefeller Institute; he also met and visited others who became influential in his career, such as Keith Porter, Francis Peyton Rous, and Gertrude and Werner Henle. At BSI and the Rockefeller, Sir Anthony developed his skills in electron microscopy, which would be essential to his discovery of the Epstein-Barr virus in 1964.
From his time at Trinity College, Sir Anthony had a keen research focus on tumour viruses; his earliest work on the Rous sarcoma virus formed the thesis research for both his MD and PHD. The decisive turning point in his career came on 22 March 1961 when he attended a talk by Dr Denis Burkitt at the Middlesex Hospital. Burkitt described a new malignant childhood lymphoma which he had observed while working as a surgeon in Uganda, speculating that the origin was a biological agent. Sir Anthony's prior work on the oncogenic Rous virus led him to decide immediately to investigate Burkitt's lymphoma for a similar viral origin.
Through a trip to East Africa supported by Burkitt and financed by the British Empire Cancer Research Campaign (now Cancer Research UK), Sir Anthony arranged for a supply of Burkitt's lymphoma biopsy samples to be sent to his laboratory at the BSI. Two pathology researchers, Dr Yvonne Barr (now Balding) and Dr Bert Achong, were recruited to work on the project. This partnership, as well as Sir Anthony's decision to grow malignant cell lines out of singular cells, led to a critical breakthrough. On 24 February 1964, Sir Anthony, Achong, and Barr observed virus particles in a Burkitt's lymphoma-derived cell for the first time. This new 'herpes-type' agent, later named the Epstein-Barr virus (EBV), is now known to infect some 90 percent of individuals in the United Kingdom before adulthood.
Sir Anthony was promoted to Head of the Department of Pathology at the BSI, but left the institute to take up a Professorship in Pathology at the University of Bristol three years later. He retired from this position in 1985. During this time, Sir Anthony and his collaborators identified EBV as the causative agent of infectious mononucleosis (IM; or glandular fever) and an important causative factor in the development of Burkitt's lymphoma and nasopharyngeal carcinoma. He also spearheaded proposals for the development of a vaccine against EBV, a cause which received support from the Cancer Research Campaign (now Cancer Research UK) and the Medical Research Council. After his retirement, Sir Anthony became Emeritus Professor of Pathology at Nuffield Department of Clinical Medicine, University of Oxford, and a Fellow of Wolfson College, Oxford. Work on the EBV vaccine continued to gain traction. By 2004, successful Phase I, Phase II, and double-blind placebo trials of a vaccine prototype had been completed. In 2005, it was discovered that this prototype could effectively protect against IM. According to Sir Anthony, his role in co-ordinating preliminary planning for human trails of the EBV vaccine was his 'final scientific contribution'.
A prolific writer in the natural sciences, Sir Anthony is the author of 252 publications in major scientific journals, as well as 6 books. He was the joint founder editor of the International Review of Experimental Pathology, 1980–1986, a member of the editorial boards of eight international scientific journals, and an advisor or reviewer for twenty other journals. Sir Anthony made frequent appearances in the media and often engaged with the public on his research through interviews, correspondences, and contributions to educational materials. He has received many honours, awards, and prizes throughout his life. Sir Anthony was made a Commander of the British Empire (CBE) in 1985 and a Knight Bachelor in 1991.