Central nervous system demyelinating disease following GenHevac B (R) vaccination: spontaneous reports over a 10-year period (1989-1999)

OBJECTIVES: To describe and analyze spontaneous reports of central nervous system (CNS) demyelinating disease including multiple sclerosis, following vaccination with GenHevac B(R) vaccine, from 1989 to December 31,1998. METHODS: Descriptive analysis of adverse event reports in the vaccinated po pulation, including the number of cases of CNS demyelinating disease, their frequencies, their dates of onset in relation to dates of report and their distribution according to age, sex and the number of injections. A Kaplan- Meier curve was used to analyze the time period between the last dose of va ccine and the onset of CNS demyelinating disease. RESULTS: Overall, 187 cases of CNS demyelinating disease were spontaneously reported, (0.54 reports per 100 000 doses GenHevac B(R) distributed). The average time period between the occuming date of onset of the disease and i ts subsequent report was 24 months, The average age of onset was 31.7 years old and 73% of cases were women. The time between the last dose of vaccine and the onset of disease was regularly distributed from 1 day to 5 years ( median : 60 days). CONCLUSION: These results, together with available clinical, epidemiologica l data regarding multiple sclerosis, do not suggest a causal relationship b etween CNS demyelinating disease and vaccination with GenHevac B(R).