Swine flu is spreading so rapidly across Britain that there could be 100,000 new cases a day by the end of next month, the health secretary, Andy Burnham, said today.
The UK would immediately move to the "treatment phase" of its plan to combat swine flu, meaning doctors would no longer test for the H1N1 virus and urge anyone with symptoms to stay at home, Burnham told the House of Commons.
The first swine flu vaccine would be made available from August, with 60m doses available by the end of the year, he added.
"We have reached the next stage in management of the disease," Burnham said. "The national focus will be on treating the increasing numbers affected by swine flu. We will move to this treatment phase across the UK with immediate effect."
The move does not mean the H1N1 virus, which was declared a pandemic by the World Health Organisation last month, is becoming more deadly, just that it can no longer be contained.
Burnham said there was a "considerable rise" in swine flu cases last week.
"We have always known it would be impossible to contain the virus indefinitely and at some point we would need to move away from containment to treatment.
"Cases are doubling every week and on this trend we could see over 100,000 cases per day by the end of August.
"The pressure on the system is such that it is the right time to take this step. Scientists can expect to see rapid rises in the number of cases."
Burnham added that the public should be reassured by the steps being taken to tackle the virus. He said: "We are the only country in the world to be able to offer anti-virals to everyone as well as those at greater risk."
The government's chief medical officer, Professor Sir Liam Donaldson, said the production of a vaccine was "at an advanced stage" and denied that the outbreak was out of control.
Speaking at a special briefing at the Department of Health, he said: "We are continuing to take a very firm grip on this situation. We have a big stockpile of anti-virals, the biggest probably in the world. We have vaccine at an advance stage of production."
Donaldson added that despite its rapid spread, the virus outbreak was "following a predictable path".
The Health Protection Agency said a further 458 patients in England had been confirmed with swine flu, while the figure for the UK as a whole rose to 7,447.
Efforts to trace people who had been in contact with swine flu cases would now stop and schools no longer needed to close when hit by the virus, unless particular circumstances made it necessary.
The government has said that not everybody with swine flu would receive anti-viral drugs, which may be reserved for at-risk groups.
The daily collation of swine flu cases would also end because it was proving time-consuming. Instead, "more general" estimates of numbers would be given. Other affected countries already update their swine flu numbers less frequently, such as weekly or every other day.
The Scottish health secretary, Nicola Sturgeon, announced a similar shift in swine flu policy at a simultaneous briefing in Edinburgh.
She said: "We've always said it would be impossible to limit the spread of what is a contagious virus indefinitely.
"We've always said that, when it did start to spread more widely within communities, we would require to make a judgment about when to shift efforts from intense containment to treatment, or mitigation."
Sturgeon, who is also the deputy first minister of Scotland, said "high-risk" groups such as children under five, pregnant women and the elderly would get priority access to medication.
Scotland's chief medical officer, Harry Burns, said the country could expect to have a tenth of the UK cases of swine flu. He predicted there would be about 10,000 new cases a day in Scotland by August.
He said: "It could be a bit less, it could be a bit more. It also presupposes that there isn't a downturn, if it continues to rise at this rate, and it's doubling approximately every week, you can do the sums yourself."
However, Scottish health officials said the swine flu infection rate may have already peaked, as the number of new cases in three hotspots in the greater Glasgow area appears to be in decline.
After infection rates peaked at 111 confirmed cases on 25 June, with Scotland experiencing the first two swine flu deaths in Europe, the rate has remained steady at about 60 new cases a day over the last week.
The rapid spread in two of the major hotspots – Dunoon in Argyll and Paisley south of Glasgow – now appears to have stopped and cases have begun to decline sharply.
The official statistics on the virus were likely to underestimate the true scale of infection in the UK because now only a sample of patients in the hotspots had a diagnosis of swine flu confirmed by lab tests. Many people were thought to have such mild symptoms that they were not bothering to contact their doctors while others were being treated in surgeries without being regarded as suspected swine flu cases.
In swine flu hotspots such as London, the West Midlands and parts of Scotland diagnosis of the virus was already being done by doctors rather than laboratory testing, and tracing the contacts of people with swine flu and the use of preventative anti-viral drugs had stopped. Anti-viral drugs were still being offered to all people with symptoms.
Although a bout of swine flu was currently causing less serious illness than traditional seasonal flu, three people with other serious health conditions in the UK have died after catching the virus and there are concerns it could mutate into a more virulent form.
The chief medical officer, Sir Liam Donaldson, has warned that there may be tens of thousands of cases each week this autumn, because the virus is more likely to thrive in a colder climate.
