Currently, all planning for the forthcoming vaccination programme has been based on the belief that patients will require two doses of the vaccine, which would earn practices £10.50 per patient.
But speaking at a media briefing in central London yesterday, Sir Liam said that one dose may be enough.
Sir Liam's comments follow the publication of two studies in the New England Journal of Medicine which found that just one dose of swine flu vaccine was enough to offer immunity.
Professor David Salisbury, DoH director for immunisation, added that the data for one dose looked encouraging but warned that the studies were performed in healthy adults.
‘In paediatrics the data is not so encouraging. Some groups such as children may still require two doses of the vaccine,' he said.
Also at the briefing, Sir Liam announced that the number of cases of swine flu in England have increased for the second successive week.
There were 9,200 confirmed cases of swine flu this week, almost a doubling of cases from last week.
It is believed that the rise in cases is being fuelled by the start of the new school term, with 66 school outbreaks already reported since the start of the autumn term.