More than 11 million people in the UK will be the first to receive the swine flu vaccine, the Government announced today.
Those aged six months to 65 in at-risk groups - including people with asthma, diabetes, heart disease, renal disease or with a compromised immune system - will be first in the queue to get the jab from October.
They will be followed by all pregnant women subject to licensing arrangements on the most suitable trimester to give the jab.
Next to get the vaccine will be people living in households with patients with compromised immune systems followed by anyone over 65 in a conventional at-risk group.
Healthy people of any age - including children - will not be given the jab in the coming months.
Exact decisions on whether they will be vaccinated and when have not yet been made.
At the same time as at-risk groups are vaccinated, frontline health and social care workers will get the jab.
In total, some 9.4 million people in the UK will receive the vaccine if they fall into priority groups, alongside 2.1 million frontline health and social care workers.
Chief Medical Officer Sir Liam Donaldson said it was a "difficult decision" but groups had to be prioritised to get the jab.
On healthy people, Sir Liam said the Government would watch how the virus spread as the UK approached winter, adding that there was not enough vaccine for everybody at the moment.
He added: "We are looking at the prospect of extending the vaccine to healthy groups and the timing of that.
"It's simply that we have to protect the most vulnerable and I think people will understand that."
The vaccine is given in two doses, approximately three weeks apart.
This month, 300,000 doses of the vaccine will have been delivered by the manufacturers and 54.6 million doses will have arrived by the end of the year.
Trials of the vaccines are taking place in England and across Europe this month and the European Medicines Agency is expected to licence the jab in late September or early October.
Two companies - GlaxoSmithKline and Baxter - are making batches of the drug, although Baxter has experienced problems.
It has informed the Government it is unlikely to be able to meet agreements on the number of doses it can supply.
The scale of the shortfall has not yet been determined but Sir Liam said most of the vaccine would be produced by GSK.
Figures out today showed the number of people newly diagnosed with swine flu continues to fall, with 25,000 new cases in England in the last week.
A total of 371 patients are currently in hospital as a result of swine flu, of whom 39 are in intensive care.
The number of confirmed deaths linked to the virus is now 44, up on the 36 in the previous week.
Experts have said the number of new cases of swine flu should continue to fall while schools and universities are on their summer holidays.
Sir Liam also announced plans to scale down the National Pandemic Flu Service for England, from around 1,600 call centre agents at its launch to between 200 and 600 from August 23.
Demand for the service has begun to fall off but is expected to rise with an anticipated "second wave" of swine flu in the autumn, in which case the service can be scaled back up.
"There's still activity," Sir Liam said. "It's not a minor thing to have 371 people in hospital due to this disease and 39 of them in intensive care, but it's certainly an improvement on last week and the week before that."
However, he said there had been an increase in the proportion of deaths among people who were previously healthy.
Of the eight deaths confirmed in the last week, five were among previously healthy people, he said.
The proportion of deaths involving healthy people has almost doubled, from 12% of deaths to 21% in a week.
Professor David Salisbury, the Government's director of immunisation, suggested at-risk groups should have had their jab by Christmas.
He said: "October, November going into December, we should get a really good hit on at-risk groups.
"It would be really nice to get those at-risk groups done as soon as we can."
The vaccine has been tested on children aged three and over but Prof Salisbury insisted the benefit of giving it to under-threes was "strong".
He said young children in at-risk groups had serious conditions which would be made "much worse" if they got the flu.
Professor Andrew Hall, chairman of the Joint Committee on Vaccination and Immunisation (JCVI), which drew up the priority list for vaccines, said healthy children were not included because other people were at greater risk.
Youngsters have been among the age groups hardest hit by swine flu and the under-15s currently account for 71 hospitalisations.
But Prof Hall said all the evidence showed the "vast majority" of the people badly affected by swine flu were in an at-risk group.
While children were getting a lot of infection, they were not suffering the most severely, he said.
The Government is still negotiating with the British Medical Association (BMA) on how the vaccine will be delivered.
GPs are demanding that their costs are met for taking part in the vaccination programme.
It is anticipated the normal seasonal flu vaccine may be given at the same time as the swine flu jab.
UK trials of the jab involve both children and adults.
One trial on about 300 adults is being held in Leicester while a second trial, involving around 900 children, is taking place in Oxford, Bristol, Southampton and Hertfordshire.
Health Secretary Andy Burnham said: "The UK will be one of the first countries in the world to receive a vaccine supply, thanks to contracts put in place by the Government in advance of the pandemic.
"Ministers from all four nations have today accepted the advice of the Joint Committee on Vaccination and Immunisation on priority groups for H1N1 vaccination.
"We are now working with BMA and NHS organisations to reach a comprehensive swine flu vaccine implementation plan for this first stage of the programme.
"Although the virus has so far proved to be mild in most people, for others it has been more serious.
"By vaccinating high risk groups first, we aim to protect those most vulnerable to this virus.
"Our decisions at all times are based on advice from the most eminent specialists, and this will continue to be the case as we go forward."Reuse content