April 25, 2011
A swine flu vaccine which has been given to thousands of children in Britain may cause the sleep disorder narcolepsy.
Symptoms include excessive daytime sleepiness and nodding off suddenly without warning.
All packets of the vaccine Pandemrix will have to carry a warning about the risk following a ruling by the EU regulator, the European Medicines Agency (EMA).
The EMA, which is currently investigating the effects of the vaccine, has also told doctors to weigh up the potential risks before injecting children against the deadly H1N1 virus.