Health officials are considering the possibility of combining protection against swine flu within the seasonal flu vaccine, the Sunday Tribune has learned.

While much depends on the outcome of clinical trials, this could mean at-risk patients who obtain the traditional flu vaccine would automatically receive immunisation from swine flu – without having to get a separate injection.

Such a move would be in line with recent advice from the World Health Organisation, which recommended that this year's seasonal flu vaccine in the northern hemisphere should include protection against three strains, including the H1N1 virus.

A spokeswoman for the HSE stressed that no decision had yet been taken on how best to protect against any 'second wave' of swine flu, and that this would be based on the expert advice it received.

It is understood that some vulnerable groups may also be administered a separate swine-flu jab if this is deemed necessary, regardless of whether they have received protection as part of a seasonal flu jab.

"What we will have this year as every year is a seasonal flu vaccination campaign. The final details of that have yet to be concluded but the possibility of including protection against swine flu in that is a possibility," she said.

Although the HSE expects the current stocks of vaccines to be effective in tackling any resurgence of swine flu, the spokeswoman warned it cannot rule out having to purchase entirely new stocks of an "updated" vaccine to take account of any changes in the make-up of the virus.

"All the international evidence to date points to the virus not changing," she said. "The HSE has 900,000 doses of the Pandemrix vaccine in stock at the national cold chain service which does not expire until September 2011."

But she acknowledged the HSE also has 250,000 doses of a second vaccine, Celvapan, which will have to be thrown away once it expires at the end of September.

Figures previously re­leased by the HSE to this newspaper show that it spent almost €13m buying three million doses of the vaccine –but just 1.1 million shots were actually administered to members of the public.

The overall cost for the swine flu vaccination campaign now stands at €36.5m.