A little over a month ago, we reported a swine flu vaccine scare suggesting a link with narcolepsy in children. The scare cited 795 reported narcolepsy cases in 30 million vaccine recipients, to which ACSH s Dr. Gilbert Ross said Incidence of narcolepsy in the general population is estimated to be between 200-500 cases per million. Meaning that the incidence of narcolepsy in vaccine recipients appears to be less than the general population.
Now, researchers at Britain s Health Protection Agency (HPA), stated that the vaccination was associated with a 14 to 16- fold increase in likelihood of developing the chronic sleep disorder narcolepsy.
The study itself, published in the British Medical Journal, examined 75 children between the ages of four and 18 who were diagnosed with narcolepsy from January 2008. They found that 11 of these children had received the vaccine, Pandemrix, before the symptoms began. After adjusting for other clinical conditions, the scientists found that the vaccination was associated with about a 14-fold increased risk of narcolepsy translating into roughly one in 50,000.
The data again do not necessarily indicate a causal relationship, says Dr. Ross. And the risk of getting sick from the virus is much higher than the risk of getting narcolepsy. In fact, none of this information indicates a specific factor that might be causal in such an exceedingly rare effect, if it is real. It could be the vaccine, albeit most unlikely; or the adjuvant, or the influenza virus, or merely a function of better awareness and data collection.
