A swine flu vaccine has been linked to rare cases of serious sleeping disorder and should be used as the last line of protection for adolescents, warn European watchdogs. Pandemrix has been deemed inappropriate for children under the age of twenty and should only be given to children who are at risk of H1N1 flu if other vaccines are unavailable.
The EMA (European Medicine Agency) said that six million doses of the vaccine have been given in the UK. Pandemrix could trigger narcolepsy, a rare disorder which causes a person to fall asleep suddenly and unexpectedly with potentially hazardous effects. The cause of narcolepsy remains unclear. Some people may be predisposed to the condition by their genetics.
Suggested initial triggers include infections such as measles or mumps, accidents and the hormonal changes that take place in puberty. It most often begins between the ages of fifteen and thirty. Pandemrix made by GlaxoSmithKline was the most widely used in the UK during the 2009/10 flu epidemic. However, the jab is no longer in use and the remaining stocks will be destroyed this autumn.
Studies found a six- to thirteen-fold increased risk of narcolepsy in children and adolescents vaccinated with Pandemrix in comparison to unvaccinated children. But the EMA said vaccine is likely to have interacted with genetic or environmental factors which might elevate the risk of narcolepsy. No increased risk was found in adults over the age of twenty.
Overall, Pandemrix has been given to more than thirty-one million people worldwide. A statement by GSK stated it had received three hundred and thirty five cases of narcolepsy in people vaccinated with Pandemrix. GSK is committed to safety of patients and will continue to work closely with the EMA and other national regulatory organizations in the best interest of patients, stated the company.
The annual seasonal flu vaccines have not been linked to the development of narcolepsy, and there are no new safety concerns associated with these vaccines, explained a spokesperson from MHRA. The regulatory action for Pandemrix vaccines recognizes the potential seriousness of H1N1 infection and ensures the vaccine remains a licensed option to protect children.