The number of new cases of swine flu have fallen again in the past week
Predictions that 65,000 people could die from swine flu in the UK this winter are unlikely to be realised, latest figures suggest.
Government scientific advisers have revised the figure to produce a worst-case scenario of 19,000 deaths.
That is based on one in three people becoming infected, said England's chief medical officer, Sir Liam Donaldson.
Cases of swine flu continue to drop off with only 4,500 new cases in England last week.
The virus is still causing mild illness in most people but some suffer serious complications and Sir Liam warned against complacency.
There are currently 159 patients in hospital, 31 of those in a critical condition in intensive care, which is lower than it has been but is a very unusual figure for this time of year, the government said.
The death toll in the UK now stands at 70 - 61 in England, seven in Scotland and one each in Wales and Northern Ireland.
Overall the pressure on the health service is falling, as it has done throughout the past month.
And demand for the National Flu Service, the web and phone service which is operational in England, has also dropped off.
But experts are still expecting a surge in cases as winter approaches but they believe figures are unlikely to peak before mid October.
In an average year around 6,000 to 8,000 people die from seasonal flu.
The new figures of 19,000 deaths from swine flu compare with the levels seen in the last seasonal flu epidemic in 1999-00.
If only one in 20 people were infected, deaths could be as low as 3,000, the latest modelling shows.
Previous estimates, which included the 65,000 figure, were based on an assumption that the death rate could be as high as 0.35% but advisors have now agreed that it is more likely to be 0.1%.
Commenting on the reduced estimates, Sir Liam said the figures may be revised again once a vaccination programme is introduced.
"We want the NHS to plan for a worst case scenario."
He added: "We are very unlikely to see a peak before the second half of October, which is something we're pleased about because we're expecting to be able to use the vaccine during October."
Meanwhile, scientists at Leicester University conducting a trial in humans on a swine flu vaccine developed by Novartis have reported that one dose might be enough to produce a good immune response.
Plans for a vaccine programme have so far been based on people needing two doses to protect them against the virus, but one dose would mean more vaccine to go around.
The UK has vaccine contracts with GlaxoSmithKline and Baxter but Sir Liam said it was too soon to know whether one dose would be enough.
"It's too early to say whether the early results can be generalised.
"We will watch carefully but we're not at this stage starting to think about one dose rather than two."