The MPA initiates research on vaccine safety and narcolepsy
Thursday, February 02, 2012
The Medical Products Agency (MPA) has previously presented results from studies performed in Sweden on the safety of the pandemic vaccine Pandemrix. To further elucidate an association between narcolepsy and vaccination the MPA has initiated further research. The studies are coordinated by the MPA and are conducted both by in-house and by independent researchers and are expected to be ongoing during 2012.
An association between narcolepsy and Pandemrix in children and adolescents (<20 years of age) has been shown in scientific studies. A variety of factors are suspected to be related to falling ill in narcolepsy. Besides hereditary/genetic characteristics factors such as infection with influenza or other infections have been discussed. However, it is not clear to what extent these factors really are triggers or if there is just a temporal relationship. It is of great importance to gain a better understanding of any mechanism explaining the increased risk of narcolepsy. The MPA has therefore taken on to coordinate further research.
Important issues that need to be addressed are:
- How can the increased prevalence of narcolepsy in children and adolescents vaccinated with Pandemrix be explained?
- To what extent do genetic factors explain an increased susceptibility to narcolepsy?
- Which immunological mechanisms could explain an association between vaccination and/or H1N1 infection and narcolepsy?
- What explains the difference in narcolepsy-incidence between northern and southern parts of Sweden?
- Is it possible to identify risk factors/mechanisms for the development of autoimmune disease related to vaccination?
- What impact has the H1N1 infection and other infections, and their relation to the time point for immunization for the development of narcolepsy?
- Does the clinical picture of narcolepsy cases associated with vaccination with Pandemrix differ from the ordinary presentation of the disease?
- How will the incidence of narcolepsy develop after the pandemic period in relation to the known disease prevalence in Sweden?
Researchers at the Karolinska Institutet (KI), the Swedish Institute for Communicable Disease Control (SMI) and the Medical Products Agency are responsible for the project which will be ongoing during 2012.
The results of the planned studies are important for the understanding of the relationship between vaccination with Pandemrix and the onset of narcolepsy and may also increase the knowledge of other diseases mediated by autoimmune mechanisms. Answers to questions about the relationship between vaccination and infections and autoimmune disease given by these studies could contribute to improved vaccine safety.