Currently based in Canada, Bill was one of the earliest advocates of a harm reduction approach towards people who use drugs. From 1985 until 1988 he was Drug Education Officer at the Terrence Higgins Trust (THT) in London, England. In 1988 Bill moved to West Berkshire Health Authority, where he created and delivered one of the first training courses for doctors on AIDS and methadone prescribing.
From 1989 to 1992, Bill attended the London School of Economics and graduated with a BSc Econ in Government and Social Policy. From 1992 until 1999, he worked as a Senior Manager in the UK National Health Service (NHS) providing palliative care and hospice at home services to people with AIDS.
In 1999, Bill left the NHS to found the UK Methadone Alliance to provide advocacy and support to people in treatment. In 2004, Bill returned to his native Canada where he has worked on the National Drug Treatment Strategy.
Bill is also active in the medical marijuana field with a particular interest in marijuana as a pain management strategy.
Bill Nelles received the Honoured Life Member Award from Harm Reduction International in recognition of his 'outstanding and distinguished service to Harm Reduction International'.