The UK Government has signed a deal with vaccine manufacturers GlaxoSmithKline and Baxter to secure up to 90 million doses of the H1N1 (swine flu) vaccine before a pandemic begins.
The agreement will ensure that there is enough of the vaccine to protect the most vulnerable sectors of the British population, regardless of whether the strain becomes a pandemic or not.
By December enough of the vaccine will be available to protect frontline health and social care workers, older people, those in clinical risk groups and children.
Secretary of State for Health, Alan Johnson said that the UK has so far been effective in containing the spread of the virus, but that preparation for a full-blown pandemic was still very important.
"Scientists tell us that as yet we don't know enough about this novel strain, or whether it's likely to mutate, but that this virus has the potential to become a pandemic and we can't predict how serious that would be," Johnson said.
"We have advance purchase agreements to provide vaccine for the entire UK population which will take effect when Phase 6 pandemic is declared. It will then take over a year for all the vaccine necessary to be provided."
Johnson also added that if the World Health Organization had to raise the threat level from level five to six, advance supply agreements would then take precedence over pre-pandemic contracts.
If a pandemic is declared, advance supply agreements signed by the Government with GSK and Baxter in July 2007, will enable the UK to purchase up to 132 million doses of pandemic-specific vaccine, when it becomes available.
By Daniel Garrun.