Pharmaceutical company GSK has told the High Court that no causal link has been established between the Pandemrix swine flu vaccine and the sleep disorder narcolepsy.

The submission was made by lawyers for GSK Biological in a case taken by a now 26-year-old woman who says she developed narcolepsy from the Pandemrix swine flu vaccine.

Senior Counsel Douglas Clarke told the court that despite ten years of research no link has been found.

Mr Clarke said at the outset that GSK wanted to sympathise with Aoife Bennett and that GSK's defence in the case should not been seen as a criticism of Ms Bennett.

However, he said the claims made against GSK were "at their most neutral, misplaced".

He said the allegations made against GSK that it produced a defective vaccine, that it was negligent and that it failed to tell the truth or allegedly suppressed information and had engaged in a constitutional conspiracy were very grave.

Each of the allegations was rooted in a multiplicity of misplaced contentions and assertions which overlooked critical features of the factual, regulatory, scientific and technological context against which the claims must be assessed.

He said the Pandemrix vaccine was designed and manufactured in emergency circumstances in response to a swine flu pandemic declared by the World Health Organisation. GSK meticulously adhered to the requirements of good clinical practices and regulations laid down by the World Health Organisation, the European Medicines Agency and other authorities, he said.

He said GSK takes the safety of individuals and families extremely seriously and was committed to the highest standards of patient safety.

He said he would produce "powerful evidence" in this case that the level of safety of the product was that which a person was generally entitled to expect and that Pandemrix was not a defective product.

GSK could never have foreseen that Pandemrix could cause narcolepsy and it was not accepted that it did, Mr Clarke added. He said it was scientifically and technologically impossible to know that a person could or would suffer from narcolepsy when the vaccine was put into circulation.

He said the core of the plaintiff's case was not that the product was defective in design or manufacture, but that she was not given the patient information leaflet.

Mr Clarke said contrary to claims that the vaccine had never been tested on teenagers, 100 children between the ages of ten and 17 had been part of a clinical trial.

Mr Clarke also referred to an article in the British Medical journal which referred to Aoife Bennett's case and questioned the safety of the vaccine over others. He said four articles were published in response to the medical journal, one from the European Medicines Agency described its contents as flawed and misleading.

Senior Counsel Rossa Fanning for the Health Products Regulatory Authority which was previously the Irish Medicines Board said the case against it was paper thin.

Mr Fanning said the HPRA had not in fact authorised Pandemrix. It had been done at EU level with the agreement of all member states. A suggestion that the HPRA was a watchdog that did not bark was no more than "a facile soundbite".

He said the body had no role whatsoever in public health programmes. It had a narrow and precisely defined function set down by statute. Its role related to two things, the authorisation of products and post authorisation activities known as pharmacovigilance.

Marketing authorisation for a product may be given at (EU) community level or member state level and in the case of Pandemrix it was authorised by the European Medicines Agency.

He said the plaintiff's legal team had sought to cherry pick a few cautionary comments made by the Irish Medicines Board which were made prior to the authorisation of the vaccine on 29 September 2009. After the 29 September there was a "completely different landscape".

The Pandemrix and Celvaplan vaccines had been approved and there was a 26 member state consensus view that the benefit risk profile was positive and that "never altered", he said. He said the IMB was fully supportive of the use of Pandemrix at the time it was rolled out here in November. 

Earlier, counsel for the State Paul Gallagher said allegations by the plaintiff that the Chief Medical Officer Tony Holohan had misled the public amounted to an extraordinary attack and were totally unjustified.

Mr Gallagher said they had identified statements made by Mr Holohan where the equivalent statement or position was put forward by expert bodies.

He also said the claims that the indemnity clauses in the HSE's contract with GSK somehow controlled how the State would conduct its cases was "completely and utterly wrong". None of the clauses in the contract was inappropriate and all were unremarkable, he said.

The suggestion that there was a "constitutional conspiracy" or something sordid and that the HSE had handed over control of legal proceedings to a third party was "very wrong and should be withdrawn", he said.

Aoife Bennett was 16 when she got the vaccine as part of a vaccination programme, administered by the HSE, amid concern over a potential human swine flu pandemic in 2009.

It is the first case over an alleged link between the vaccine and narcolepsy and is regarded as a test case for as many as 100 other legal actions.

Ms Bennett of Lakelands, Naas in Co Kildare has sued the Minister, the HSE, the producer of the vaccine, Glaxo Smith Kline Biologicals and the Health Products Regulatory Authority.

Her lawyers told the court it was "unforgivable" of the HSE not to tell Aoife and her parents what they knew about it at the time. They claimed the Pandemrix vaccine was never tested on teenagers.

Narcolepsy is autoimmune disease which is incurable. Ms Bennett suffers excessive daytime sleepiness and episodes of sudden weakness known as cataplexy.