Katie Stephen, 21, from Stonehaven in Aberdeenshire, lost the use of her left ear days after being inoculated as a toddler.

She is the first known victim to prove her case to the Vaccine Damage Payments Unit, but she has been refused £120,000 compensation because she still has hearing in her right ear, so does not meet Government criteria for 60% or more disability.

Ms Stephen was deafened by a vaccine carrying the botched Urabe strain of mumps, which was later withdrawn. She has difficulty using the telephone and blocking out background noise, and said: "If the shower is running, someone is hoovering or even the washing machine is rumbling away in the next room, I find myself completely unaware of my partner or members of my family talking directly to me."

A spokesman for the Department of Work and Pensions said: "It was considered at the inception of the scheme that disablement should be assessed as a percentage similar to the system applied in the War Pensions and Industrial Injury Schemes."