Hepatitis B vaccine and the risk of CNS inflammatory demyelination in childhood.

In a new analysis of a case-control study based on the French KIDSEP cohort, Mikaeloff et al.1 conclude that there is no overall association of hepatitis B vaccine (HB) with acute onset demyelinating disease but that there is a long-term increase in the risk of multiple sclerosis (MS) in children compliant with national vaccination schedules and immunized against HB with the Engerix B® vaccine. Unfortunately, these results were leaked to the lay press before their publication in Neurology ®, fueling new rumors about the risk of HB vaccination. We would like to stress major interpretational issues that preclude any reliable conclusion from being drawn about a possible link in this study between the Engerix R® vaccine and the risk of MS in children. A very large number of analyses were undertaken. A total of 50 results appear in the article, and the list of “sensitivity” analyses suggests that many more were done. The probability of detecting several significant associations through pure chance was therefore very high. Concluding that there is a difference between Engerix B® and other vaccines because the odds …