A nationwide vaccination programme to counter the H1N1 swine flu virus begins in Britain on Wednesday, beginning with frontline health workers and those in at-risk groups.

More than 100 deaths have been linked to the flu in Britain and the mass immunisation will take place ahead of a feared second wave of infections this winter.

"This is the first pandemic for which we have had vaccine to protect people," said Liam Donaldson, England's chief medical officer.

"I urge everyone in the priority groups to have the vaccine -- it will help prevent people in clinical risk groups from getting swine flu and the complications that may arise from it."    

Hospital staff will be the first to be vaccinated to prevent them catching the virus or spreading it to patients. Eventually about two million frontline health and social care workers will be offered the vaccine.

The government has also designated a number of at risk groups who will be included in the first wave of the programme when it is extended across GP surgeries.

These will be those aged over six months who fall into current seasonal flu risk groups, all pregnant women, and contacts of people with compromised immune systems.

In total, around 11 million people are in line for the first phase of vaccination with most people only needing one dose.

"Our best line of defence against swine flu is the vaccine," said Health Secretary Andy Burnham.

"I'm very pleased to say that the UK is one of the first countries in the world to start vaccinating against this virus."    

Similar vaccination programmes are already under way in the United States, China and Australia. - Reuters