Sir Liam Donaldson: GPs not under swine flu pressure
Hospital intensive care wards are under "a lot of pressure" as a result of the swine flu pandemic, the UK government's most senior medical adviser has said.
Sir Liam Donaldson said a shortage of beds was a "concern" as more people are being hit with severe symptoms.
He told BBC One's Andrew Marr Show the UK's vaccination programme should help contain the spread of the virus.
Some 137 people with swine flu have died in the UK, with more than 500,000 having been infected.
However, Sir Liam said the number of people affected by the virus had increased at a slower rate than feared.
But he added: "What we are seeing is that while most people generally get a mild illness, a small proportion of people are getting very serious illnesses.
"It's taking them into hospital and a small proportion are dying."
Latest figures show there have been 97 swine flu-related deaths in England, 25 in Scotland, eight in Northern Ireland and seven in Wales.
Asked how the NHS was coping, Sir Liam said the strain on GPs had been relieved by patients ability to be assessed and get anti-virals using the internet or phone.
He said: "On the hospital side the intensive care beds are under a lot of pressure.
"We have plans to expand them but that is a concern at the moment - the serious end of the spectrum, the hospitalised patients."
He said serious cases were likely to become more prevalent as "flu season" approached.
A government vaccination programme for those most at risk, such as seriously ill hospital patients, health workers and pregnant women, was launched last month.
However, it could be mid-December before the nine million people in priority groups receive their vaccinations.
Sir Liam said the slower-than-expected rate of spread would give "breathing space" to deliver the jabs.
"Every day that goes by more people will be getting the vaccination," he said.
"The deliveries to GPs started last week so people in priority groups will start to get the vaccine over the next few weeks."
Asked about reports that the programme could be extended to cover under 18s, Sir Liam added: "We haven't come to any final decisions about that yet."