Health reporter, BBC News
The under fives remain at risk and should be vaccinated, say officials
The government is making plans to offload millions of doses of swine flu vaccine amid predictions a "third wave" of the pandemic is unlikely to happen.
Officials are in discussion with manufacturer GSK over contracts for remaining doses purchased by the UK.
Options include selling surplus vaccine and donating it to poorer countries but a stockpile will remain in place.
Cases of swine flu have now dropped dramatically to well below what is usually seen in winter flu outbreaks.
Last week France announced it was selling millions of doses of swine flu vaccine after finding they had more than enough to cope with the outbreak.
The UK bought 60m doses of swine flu vaccine from GSK and 30m from Baxter but the smaller contract had a break clause should the doses not be needed.
To date 23.9m doses of GSK vaccine have been delivered for immunisation of priority groups in the UK as well as 5m Baxter vaccines.
An official figure for the cost of the vaccine to the UK has never been given but it is likely to run into hundreds of millions.
In addition to selling or donating vaccine, another option under consideration is to keep supplies of the vaccine adjuvant, the booster chemical which is produced separately from the vaccine, to use in future pandemics.
It has a shelf life of five years.
Government immunisation lead Professor David Salisbury said: "We are in discussion with GSK about future supplies of the vaccine.
"We have to keep a stockpile for ourselves anyway because we don't know what's going to happen in 2010.
"If there was a resurgence we would look very foolish if we had disposed of a valuable stockpile."
He added that it remains important for high-risk groups, such as those with underlying illness and the under fives to be immunised as they are more likely to have severe complications.
Michael Summers, vice chair of the Patient's Association, said it would have been a "dereliction of duty" if the government had not ordered enough vaccine to cover everyone.
But he added there were "lessons to be learnt" about negotiating contracts of this size.
Although the number of cases of swine flu has fallen to a low of below 5,000 in England in the past week, the number of people in hospital after being infected has not dropped to the same extent.
There has also been a striking increase in critical care admissions in the over 65s who make up a quarter of the 103 patients currently taking up intensive care beds.
Around a third of those in initial priority groups - including those with underlying health problems - have had the swine flu vaccine
Roughly one in five pregnant women have been immunised
Among healthcare workers, 37% have had the vaccine
So far 86,000 under fives have been vaccinated
This could partly be due to the cold weather but the reason is not yet entirely clear.
Since swine flu was first reported in April 2009 there have been 360 deaths across the UK - 251 in England, 28 in Wales, 64 in Scotland and 17 in Northern Ireland - mostly in people with underlying health conditions.
Chief Medical Officer, Sir Liam Donaldson, said they would be calculating the economic costs of the pandemic at a later date.
"We're in the 21st century and people do not need to die from vaccine preventable illnesses.
"We want to prevent deaths, people going to hospital and that's generally been the approach we have taken."
Ian Dalton, national director of NHS flu resilience, said NHS staff were making huge efforts to keep services going amid pressures caused by the current cold weather.
"All the work done with flu preparedness will help us in the adverse conditions," he said.