Peter Medawar’s work addressed a problem that stood between a transplanted tissue and its acceptance by the body: the immune system could recognise the graft as foreign and reject it. Through experiments with colleagues Leslie Brent and Rupert Billingham, Medawar helped show that acquired immune tolerance could be induced. The discovery changed the direction of immunology and provided a foundation for tissue and organ transplantation. In 1960, he shared the Nobel Prize in Physiology or Medicine with Frank Macfarlane Burnet.

From Brazil to Oxford

Peter Brian Medawar was born on 28 February 1915 in Brazil. His mother, Edith Muriel Dowling, was British; his father, Nicholas Agnatius Medawar, was born in Lebanon and became a naturalised British citizen. Accounts differ over whether Peter was born in Rio de Janeiro or Petrópolis, so the precise city is best left open. He later described his British citizenship as acquired at birth through registration at the British Consulate. He spent his life in England after leaving Brazil with his family.

In 1928, Medawar went to Marlborough College in Wiltshire. He recalled being unhappy there and described hostility from some fellow pupils towards his Lebanese background. His account of the school was not wholly negative, however: he credited biology teacher Ashley Gordon Lowndes with firing his enthusiasm for the subject. Medawar went on to Magdalen College, Oxford, where he studied zoology, graduating with first-class honours in 1935. He held a scholarship and fellowship at Magdalen and worked at the Sir William Dunn School of Pathology under Howard Florey, whose example helped turn his attention towards immunology.

At Oxford, Medawar also worked with J. Z. Young on nerve regeneration. During the Second World War he developed a nerve glue that proved useful in operations on severed nerves. He completed the research for a doctoral thesis in 1941, but did not initially take the degree because he could not afford the fee. Oxford awarded him a Doctor of Science degree in 1947.

How graft rejection became a research question

Medawar’s involvement in transplantation research began during the Second World War, when he studied possible improvements to skin grafts for wounded servicemen. His early work included research on sheets of human epidermis. Skin grafting made the problem tangible: tissue transferred from one person to another could be rejected by the recipient’s body. The question was not simply how to attach a graft, but what made the immune system treat it as foreign.

After becoming Mason Professor of Zoology at the University of Birmingham in 1947, Medawar continued this work with his research group. His colleagues included doctoral student Leslie Brent and postdoctoral fellow Rupert Billingham. Their experiments tested a hypothesis advanced by Australian biologist Frank Macfarlane Burnet: that, during development, an organism acquires the ability to distinguish its own tissues from foreign material.

The team took cells from young mouse embryos and injected them into mice of a different strain. When the animals grew up, grafts of skin from the donor strain were accepted rather than rejected. The work showed that exposure early in development could produce acquired tolerance to foreign tissue. An initial account appeared in Nature in 1953; a fuller description followed in 1956, using the term “actively acquired tolerance”. This was experimental evidence for a principle with profound consequences: immune responses could, in certain circumstances, be shaped rather than merely endured.

Research, leadership and public writing

Medawar moved to University College London in 1951 as Jodrell Professor of Zoology and Comparative Anatomy. In 1962, he became director of the National Institute for Medical Research. He later led the transplantation section of the Medical Research Council’s clinical research centre at Harrow, held a professorship in experimental medicine at the Royal Institution, and served as president of the Royal Postgraduate Medical School.

His research helped shift immunology towards understanding how the immune mechanism itself might be altered, including in attempts to suppress rejection of transplanted organs. The principle of acquired tolerance became fundamental to transplantation science. It contributed to the scientific basis on which later transplant practice developed; it did not, by itself, make transplantation straightforward or eliminate the problem of rejection.

Medawar also investigated questions beyond transplantation. In his 1951 lecture “An Unsolved Problem of Biology”, he considered ageing and why natural selection might permit senescence. He argued that selection weakens with age as an organism’s prospects of continued existence and reproduction decline. His work on endocrine evolution likewise examined how the uses of hormones, rather than simply the hormones themselves, could change over evolutionary time.

He was known for making scientific ideas accessible through radio, lectures and books. In 1959, he delivered the BBC’s Reith Lectures, a series of six broadcasts titled The Future of Man, on the possible future evolution of humanity. Among his books are The Uniqueness of the Individual, The Art of the Soluble and Advice to a Young Scientist. His writing joined scientific argument to a concern with how knowledge is made and communicated; the Royal Society later recognised the contribution of his books to public understanding of science with the 1987 Michael Faraday Prize.

Honours, illness and later years

Medawar was elected a Fellow of the Royal Society in 1949. He received the Royal Medal in 1959 and shared the 1960 Nobel Prize in Physiology or Medicine with Burnet “for discovery of acquired immunological tolerance”. Later honours included the Copley Medal in 1969, the CBE in 1958, a knighthood in 1965, appointment to the Order of the Companions of Honour in 1972 and the Order of Merit in 1981. He was president of the British Association for the Advancement of Science in 1968–69.

In 1969, Medawar suffered a stroke while attending the British Association’s annual meeting in Exeter. It impaired his speech and movement, and he had further strokes. With help from his wife, Jean, he reorganised his life and continued writing and research on a more limited scale. He died in London on 2 October 1987, aged 72. In 2024, his family donated his Nobel medal to the University of Oxford.

Why Peter Medawar deserves a place in British Legacy

Medawar’s place in British Legacy rests on a specific body of work and the institutions through which it was carried out. Born in Brazil to a British mother and a Lebanese-born father who became a British citizen, he was educated at Marlborough and Oxford, then pursued research and teaching in British universities and medical institutions. At Birmingham, his group’s experiments provided evidence for acquired immune tolerance. That discovery reshaped immunology and supplied a scientific foundation for tissue and organ transplantation. The international reach of the work was recognised when Medawar and Burnet shared the 1960 Nobel Prize.

His contribution was not confined to the laboratory. As a research leader, a lecturer and an author, Medawar connected specialist science with wider questions about medicine, evolution and the nature of scientific thought. His Reith Lectures and books, alongside the Faraday Prize awarded for his science writing, are part of that record. His career also shows British science as an international enterprise: the work was built through collaboration, and its benefits extended beyond national borders. Remembering Medawar means recognising both a discovery that changed transplantation research and the public communication that helped make science part of cultural life.

Sources

Peter Medawar (revision 1375981430)

Adapted in part from Peter Medawar by Wikipedia contributors, under CC BY-SA 4.0. Text has been edited and combined with the existing article; this adapted text is shared under the same licence. Contributor history.