Sir Peter Julius Lachmann FRS FMedSci (23 December 1931 – 26 December 2020)^[1] was a British immunologist, specialising in the study of the complement system. He was emeritus Sheila Joan Smith Professor of Immunology at the University of Cambridge, a fellow of Christ's College, Cambridge and honorary fellow of Trinity College, Cambridge and of Imperial College. He was knighted for service to medical science in 2002.^[2][3][4]

Born into a Jewish family in Berlin on 23 December 1931,^[5] he moved to London in 1938. He went to school at Christ's College, Finchley,^[6] then trained in medicine at Cambridge and University College Hospital, graduating in 1956, and obtained PhD (1962) and ScD (1974) degrees at Cambridge in immunology.^{[citation needed]}

This section does not cite any sources. (January 2023)

Lachmann's primary research interest was the downregulation of the complement alternative pathway as a treatment for age related macular degeneration. He has previously worked on many aspects of complement biology; on microbial subversion of the innate immune response; on the immunology of measles, on systemic lupus erythematosus and on insect sting allergies.

He held a chair at Cambridge University and served as President of the Royal College of Pathologists, Vice President and Biological Secretary of the Royal Society, and Founder President of the UK's Academy of Medical Sciences. His posts in immunology have included Head and Honorary Head of the Medical Research Council Group on Mechanisms in Tumour Immunity and Honorary Director of the MRC Mechanisms in Tumour Immunity Unit.^{[citation needed]}

He was also at one point Associate Editor of the journal Clinical and Experimental Immunology. From 1976 to 1999, he was Honorary Clinical Immunologist with the Cambridge Health Authority. Lachmann has also won a Gold Medal from the European Complement Network in 1997, the Medicine and Europe Senior Prize of the Académie des Sciences de la Santé in 2003.^[7]

He was a member of the Norwegian Academy of Science and Letters, Foreign Fellow of the Indian National Science Academy (1997) and Honorary Foreign Member Czech Academy of Medicine (2012).^[8] He was an honorary member of the British Society for Immunology.^[9]

Lachmann helped produce the Royal Society's first report on GM crops in 1998. The report, Genetically Modified Plants for Food Use, outlined the benefits of GM plants in agriculture, medicine, food quality and safety, nutrition and health, especially in alleviating food shortage in third-world countries. This caused him to be regarded as a controversial figure by the anti-GM food lobby.^{[citation needed]}

In 1999, he tried to persuade the editor of The Lancet not to publish Árpád Pusztai's research on the adverse effects of GM potatoes on rats on the grounds that it was not sound science. The Lancet's editor, Richard Horton, said he received a "very aggressive" phone call calling him "immoral" and threatening that if he published the paper it would "have implications for his personal position" as editor.^[10]

Lachmann said that he made the call but denied that he threatened Horton and said the call was to "discuss his error of judgment" in publishing the Pusztai letter and to discuss the "moral difficulties about publishing bad science".^[10]

Lachmann's own account of GMOs and the Pusztai affair can be found in Panic Nation (2005).^[11]

Lachmann was a proponent of the defence of reason and scepticism in scientific academia and on topics that extend from vaccine scares to stem cell technology and to alternative medicine. He was also a bee keeper and this interest has led to an interest in the evolution of group behaviour in both bees and humans and the role of religious prescription as the building blocks of cultural evolution.^[12][13]