He moved to London before the First World War and was appointed as Medical Officer of Health in Finchley and St Marylebone in 1920.

[2] He was influential in the detailed planning for the introduction of the National Health Service where he worked closely with Aneurin Bevan.

Subsequently, healthcare services came to be the main focus of the work of the Chief Medical Officer, rather than public health.

[3] After retirement in 1950 he became medical adviser to the King Edward's Hospital Fund for London.

In 1952 Jameson chaired the Second British National Conference on Social Work, which was held in London.