Jonathan Simms (1984 – 5 March 2011) was a man from Belfast, Northern Ireland, who contracted the variant Creutzfeldt-Jakob Disease (vCJD) in his late teens. His life expectancy post-diagnosis was given as being only one year which is the same as other young people who were diagnosed in the same age bracket. However, due to an experimental treatment (of pentosan polysulfate), he lived for another ten years after diagnosis, although his higher functions were severely limited.