The swine flu vaccine being used in Britain contains an additive the use of which in children's jabs was stopped five years ago, over fears that it could lead to autism.
Pandemrix, which has received the green light from European drugs regulators to be given to children over six months old and pregnant women, contains the mercury-based compound Thiomersal, which has not been used in childhood vaccines since 2004.
The compound was removed from jabs in America 10 years ago, after issues were raised by the US Public Health Service.
However, the Department of Health in Britain is defending its use.
"There is no risk from Thiomersal in vaccines. The medical community is not divided on this. The only place where people say there is a problem is outside the scientific community," the Daily Express quoted Professor David Salisbury, the Director of Immunisations, as saying.
Chief Medical Officer Sir Liam Donaldson said that the number of swine flu cases was still low, but there were signs a second wave could be on its way.