Britain will start a mass vaccination program against the deadly H1N1 swine flu before the end of the month and hospital patients will be first to get the shot, the country's chief medical officer said on Thursday.

Swine flu deaths so far stand at 76 in England, 10 in Scotland, three in Northern Ireland and one in Wales.

There were an estimated 18,000 new cases of H1N1 flu in the past week, up from around 14,000 in the previous weeks, according to health officials.

Liam Donaldson said the government had around half a million doses of Baxter International's vaccine in warehouses ready for use, while delivery of the first of millions of doses of a vaccine from GlaxoSmithKline was "imminent".

The first people to be immunized will be patients in hospital who are suffering serious illnesses that make them more vulnerable to the disease.

Hospital staff who have daily contact with seriously ill people will also be at the front of the line to get the shot.

Donaldson said Britain was "well into the second wave" of swine flu, which was "proving so far to be a slow burn."

He said there was a possibility that the virus might peak at a lower level previously feared, which would be "incredibly positive news."

"Any breathing space we get ... we will take because it gives us the opportunity to fight this disease and save lives," he said.

The World Health Organization earlier this week restated its confidence in vaccination, saying it was the most important tool against the pandemic after some reports said some people were reluctant to be injected with the new vaccines.

The European Commission gave a licence for Baxter's Celvapan vaccine against H1N1 on Wednesday, following earlier green lights for Pandemrix and Focetria vaccines made by GlaxoSmithKline and Novartis.