Swine flu vaccine linked to chronic sleep disorder

FEARS that the swine flu vaccine Pandemrix may be linked to a chronic sleep disorder have been fuelled by data that has emerged just weeks before the European Centre for Disease Prevention and Control concludes a review on its safety.

The study, by Sweden’s Medical Products Agency, revealed an almost seven-fold higher incidence in vaccinated children and adolescents of narcolepsy (sudden and uncontrolled episodes of deep sleep) with cataplexy (symptom of narcolepsy that can cause sudden paralysis of the muscles, often at a time of strong emotion such as anger or laughter), compared to those who were not vaccinated.

The Irish Medicines Board has received 13 reports with clinical information which confirms a diagnosis of narcolepsy in individuals who were administered Pandemrix.

However, the board also pointed out no casual association with vaccination had been established.

There have been 850 doses of the vaccine administered in Ireland.

The Swedish agency said the new data provided “strengthened evidence that vaccination with Pandemrix is associated with an increased risk for narcolepsy with cataplexy in children and adolescents” and that further research was “urgently needed”.

The future of Pandemrix will come under the microscope when the European Medicines Agency (EMA) Committee for Medicinal Products for Human Use will hold a three-day conference from July 18-21 in the wake of a prolonged EU-wide assessment of its safety.

The Irish Medicines Board (IMB), which is represented on the committee, said yesterday that it was “in agreement” with the EMA “that additional data are needed to further assess and to understand the nature of any relationship between vaccination and narcolepsy”.

Two major studies have been ongoing for some months, including one conducted on behalf of the European Centre for Disease Control by VAESCO, a network of research and public health institutions in nine EU states, and a second study conducted by GlaxoSmithKline, manufacturer of Pandemrix. Preliminary results of both studies are expected this month.

In April, the EMA recommended the product information for Pandemrix be amended to advise prescribers to take into account preliminary results from studies on the vaccine and narcolepsy, and to perform an individual benefit-risk assessment when considering its use in children and adolescents.

The IMB recommends anyone with concerns to contact their GP.

Pandemrix has been authorised since September 2009 and was given to at least 30.8 million Europeans during the H1N1 influenza pandemic that year.

The review of Pandemrix and the occurrence of cases of narcolepsy was initiated at the request of the European Commission on August 27, 2010, following an increased number of reports on narcolepsy in Finland and Sweden.