Born in Weston-super-Mare, Comer began working as a mental health nurse at Wells Hospital.
He joined the Mental Hospital and Institutional Workers' Union (MHIWU), and was a branch secretary by the mid-1920s.
[2] In 1932, Comer began working full-time for the union as its first national organiser, based in Manchester.
[3][2] The MHIWU became part of the Confederation of Health Service Employees (COHSE) in 1946, and Comer was appointed as its first assistant general secretary and Southern National Organiser.
[4] Comer was a supporter of the Labour Party, which he represented as a member of Somerset County Council.