Investigators Find No Overall Link Between Hepatitis B Vaccine and MS
A study evaluating the potential that hepatitis B vaccination increases the risk of developing MS found no general increase in risk from exposure to the vaccine. However, the investigators did find a possible hint that a specific brand of the vaccine may increase the risk of MS, but that finding requires confirmation. The study, led by Yann Mikaeloff, MD, PhD (Assistance Publique-Hôpitaux de Paris, INSERM), evaluated vaccination records of 349 children in France who had experienced a neurologic episode. Most previous studies have found no link between MS and hepatitis B vaccine, which can prevent serious health problems associated with hepatitis B virus infection. The study will appear in the journal Neurology (early online publication, October 8, 2008).
Background: Hepatitis B virus causes some 4 million acute infections worldwide annually. More than 350 million individuals are chronic carriers of the virus after infection, and some 25% of those (some 5,000 per year in the U.S.) will die as a consequence of cirrhosis of the liver or liver cancer brought on by the viral infection. Vaccination against hepatitis B has been established to be safe and effective in helping to prevent infection and subsequent liver disease.
However, in recent years, concerns have been raised that vaccination against hepatitis B virus might increase risk for developing a variety of diseases, including MS. The concerns related to MS were due in part to a report from France in the mid-1990s of a possible increase in autoimmune diseases, including MS, after hepatitis B vaccination. However, efforts to confirm this report had been unsuccessful and two separate reports concluded that there was no evidence of an association between vaccination and the risk either of developing MS or having MS relapses (The New England Journal of Medicine, February 1, 2001). The World Health Organization and, separately, the Institute of Medicine reviewed all available data and concluded that there was no association between hepatitis B and MS.
The Study: Dr. Mikaeloff’s team evaluated cases selected from patients enrolled in “KIDSEP,” which compiles information on children with neurological disorders in France. They selected 403 patients who had one neurologic episode caused by inflammation/demyelination between January 1, 1994, and December 31, 2003, before the age of 16 years, and born in France. They matched each case with up to 12 controls selected from the general population of France.
The team sent a questionnaire to all participants, and requested a copy of the child’s vaccination history. Of the original group, 349 cases and 2941 controls responded and provided enough information to be included in the analysis.
Of the group who experienced a neurologic episode, 24.4% had been vaccinated in the three years before symptom onset, compared to 27.3% of the controls. There was no association between the development of confirmed MS and general hepatitis B vaccination. However, children who eventually developed MS were significantly more likely to have received a particular vaccine, Engerix B. In their paper, the authors suggest that since the link between MS and the Engerix B vaccine was the only one to emerge from among a number of analyses, it could have been due to chance. These results warrant confirmation to determine if indeed this link holds up and if any significant difference exists among vaccine brands.
Comment: “Importantly, overall, these findings show no association between MS and hepatitis B vaccine,” says John Richert, MD, Executive Vice President of Research & Clinical Programs. “This is in concert with the majority of published research on the subject. Future studies should determine any differences between vaccination brands, but hepatitis B is a serious disease and people should not translate these findings into a reason not to protect themselves against it.”