Winter flu death toll topped 600
Last winter's flu outbreak claimed 602 lives in the UK, with more than 70% of the deaths among 15- to 64-year-olds, Health Protection Agency figures show.
Flu normally hits older people, but last winter it acted differently as the main strain was swine flu, which the elderly have some resistance to.
The HPA figures also show just 50% of under-65s in at-risk groups in England and Wales were immunised against flu.
Officials said the vaccination uptake figures were "very concerning".
The figures were better in Scotland where 57.4% of at-risk under-65s were immunised and 74.5% of over-65s.
The flu vaccination programme was beset by problems, with some GPs reported to have run out of jabs.
The government turned to vaccines left over from the pandemic of two years ago which did not protect people against all the strains in circulation.
There were problems in encouraging more people to come forward for vaccination. Three-quarters of the at-risk groups should be vaccinated, according to targets.
However, the figures released by the Health Protection Agency show that in the healthy pregnant women group, the immunisation rate was just 37%.
The proportion of over-65s coming forward in England and Wales was better at 73%.
The death toll was actually higher than the total during the 2009 pandemic when 474 died. This has been put down to the fact that the pandemic peaked in the summer, when people are less susceptible to illness.
In both periods many more people are likely to have died with flu as a contributory factor, as the HPA records only count those where flu has been cited as a major cause on the death certificate.
Professor John Watson, of the HPA, said: "A concerted effort must be made by healthcare professionals - including GPs and midwives - to encourage those at risk to take up the offer of vaccination. It is the best way to protect against flu."
The government has responded by giving the NHS in England three years to improve uptake to 75%. It will also be setting up an emergency pot of 400,000 doses to be held centrally in case there are shortages next winter. This already happens in Scotland.
But in the long-term it is looking to see whether the whole system needs overhauling. A three-month consultation is being launched to see whether GPs should lose the responsibility for purchasing the vaccines. Under the plans, the Department of Health would take charge of ordering them and distributing them to GPs.
Slightly different systems operate elsewhere in the UK, but a move towards central buying in England could lead to a UK-wide system.
The government believes this would ensure local shortages would be avoided and could help improve uptake.
In the consultation paper, it is argued that GPs would encounter a financial risk if they ordered more vaccines as they are unable to sell on any they do not use.
Ministers also believe a central system may be more efficient, potentially shaving nearly £40m off the £180m bill.
If central purchasing was introduced, it would bring flu vaccination in line with the entire childhood immunisation programme organised by government.
Health Secretary Andrew Lansley said: "A severe flu season places considerable pressure on the NHS and, although it coped well last year, there are areas where I'm determined we can improve."
But the British Medical Association questioned whether changes were needed.
Dr Laurence Buckman, chairman of the BMA's GPs committee, said: "There is no genuine evidence that the system is not working now, so I think GPs are happy with it."
However, he said a move towards a central system would probably not be opposed.
Shadow health secretary John Healey said: "A large part of the blame for the rise in deaths from swine flu last winter lies at the door of Andrew Lansley.
"He's the one who cancelled the flu-jab advertising campaign that had previously targeted those most at risk. The health secretary should make clear what lessons he has learnt to prevent this happening again."
But the government rejected these claims, saying the vaccination problem was a long-term issue and the lack of a national advertising campaign had not made the situation worse.