The government has provided an "unlimited" indemnity to the manufacturers of the new swine flu vaccine to ensure they are not held liable for any possible adverse side effects.

The controversial move could leave the taxpayer, rather than the multinational companies who produce the drug, facing a potential multimillion euro compensation bill in the coming years.

Any claims will be administered by the State Claims Agency (SCA), although this would depend on what issues, if any, emerge in relation to the H1N1 vaccine.

A spokesman for the Department of Health said doctors administrating the swine flu vaccine will be indemnified under their own indemnity insurance for the delivery of the vaccine.

"However, the government is providing indemnity for the vaccine itself and any adverse effects it may cause in recipients," he said.

"The companies producing the vaccine have extensive experience and expertise in safe vaccine production. Similar to other countries, indemnity has been provided by the government to the two drug companies.

"This vaccine will be produced using methods that have been tried and tested in the yearly process of seasonal flu vaccine production, which is also produced over a short timeframe. These flu vaccines have had a very good safety profile."

The indemnity does not absolve the vaccine companies from compliance with the normal quality assurance standards in the production of the vaccine, he added.

The director of the SCA, Ciaran Breen, confirmed there is no limit to the indemnity offered by the state.

"Our mission is to make sure we pay out in cases which deserve to be paid out, and to ensure that, where they do not, that we limit the exposure of the taxpayer as far as possible," he said.

The move to indemnify, which is seen as essential in ensuring the vaccine is widely administered here, comes after the EU Commission last week announced it has approved two H1N1 swine flu vaccines.

But it is likely to provoke concern about the taxpayer's potential liability should any safety issues emerge from the new vaccines, whose approval was "fast tracked" to ensure their availability in the coming months.

One of the EU-approved vaccines, Pandemrix, manufactured by GlaxoSmithKline, is to be used in Ireland, with details of the mass vaccination programme to be announced by the HSE later this month.