It's being recommended by vaccine experts as another to be added to the list of mass vaccinations made available to all children - but critics are worried that the chickenpox vaccine may increase the cases of shingles in adults.

Others are also concerned by the 'vaccine load' that young children face. Currently 10 jabs are given before the age of two.

The chickenpox vaccine was approved in 2002, but was not immediately adopted for routine use.

(Source: Department of Health website).