A senior government adviser on the safety of blood transfusions has told Sky News he is "kept awake at night" worrying about the possibility of a deadly brain disease being passed from donor to patient. US researchers working with a cohort of patients with the condition between November 2023 and January 2024 established a link between the disease and blood transfusions. If blood transfusions can spread amyloid protein, even rarely, this would have important consequences for blood safety. However, it is important to remember that while we have extensive blood safety systems in place, all blood transfusions are not, and never will be, without risk. That is why it is important that all blood transfusions are given only when necessary."