The World Health Organisation said on Tuesday that Sir Jeremy Farrar would become its new chief scientist, as the agency prepares to cope with post-pandemic health challenges. Sir Jeremy, who is currently head of the Wellcome Trust, courted controversy in recent years after publicly supporting the theory of a natural origin for Covid-19 while in private emails saying he believed a lab leak was also possible. Though he publicly praised the professionalism of Chinese researchers, in private emails, Sir Jeremy said that research in Wuhan was like the “Wild West”. He also signed a letter published in <i>The Lancet</i> that “strongly condemned conspiracy theories” surrounding Covid-19, and contributed to a <i>Nature Medicine</i> article that shut down the lab leak theory at the time. More recently, Sir Jeremy said it is important to stay “open minded” about a lab leak although a natural origin is still the most likely scenario. The WHO unveiled a new team in October 2021 that was given the task of investigating the origins of the pandemic after originally ruling a lab leak was “extremely unlikely”. The organisation later said it would not be looking further into the theory. Sir Jeremy joined Wellcome in 2013 after spending 17 years as director of the clinical research unit at the Hospital for Tropical Diseases in Vietnam. He was also a member of the UK Scientific Advisory Group for Emergencies during the pandemic. Sir Jeremy will join the WHO in the second quarter of 2023, replacing Soumya Swaminathan, who departed in November before a broader shake-up at the health agency. He is the latest appointment of Director General Tedros Adhanom Ghebreyesus's second term as the leader of the 74-year-old UN health agency, the management of which some donors have described as too bloated. “As chief scientist, Jeremy will accelerate our efforts to ensure WHO, its member states and our partners benefit from cutting-edge, life-saving science and innovations,” said Dr Tedros in a statement.