title: [The first episode of central nervous system demyelinization and hepatitis B virus vaccination].
abstract: BACKGROUND
  Central nervous system (CNS) demyelinating episodes have been described following numerous vaccines but there is no definite conclusion about a causal relationship. Recently, in France, in the context of an Expanded Program on Immunization, several cases of CNS demyelination have been observed following injection of recombinant hepatitis B (HB) vaccine, leading to great concern.
  
  
  METHODS
  We performed a hospital-based case-control study of 121 patients with a first episode of CNS demyelination occuring between July 1993 and December 1995 and 121 age and sex matched controls seen in the same period. Data on vaccinations history of cases and controls were collected by a postal questionnaire and confirmed by a phone interview.
  
  
  RESULTS
  Adjusted odds ratio (OR) obtained from conditional logistic regression between a first episode of CNS demyelination and any vaccination were equal to 1.4 (95 p. 100 CI 0. 5-4.3) for an exposure within the 60 previous days and 2.1 (95 p. 100 CI 0.7-6.0) for an exposure within the 61-180 previous days. Similar results were found for HB vaccine exposure within the 60 previous days (adjusted OR=1.7, 95 p. 100 CI 0.5-6.3) or within the 61 to 180 previous days (adjusted OR= 1.5, 95 p. 100 CI 0.5-5.3).
  
  
  CONCLUSIONS
  These findings did not permit to exclude confidently an association between HB vaccine and the occurrence of a first CNS demyelinating episode.
authors.affiliation: Unité de Recherches Epidémiologiques en Neurologie et Psychopathologie, INSERM U360, Paris, France. e.touze@wanadoo.fr
authors.forename: E
authors.initials: E
authors.lastname: Touzé
authors.forename: O
authors.initials: O
authors.lastname: Gout
authors.forename: M H
authors.initials: MH
authors.lastname: Verdier-Taillefer
authors.forename: O
authors.initials: O
authors.lastname: Lyon-Caen
authors.forename: A
authors.initials: A
authors.lastname: Alpérovitch
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002490:Central Nervous System / Q000473:pathology*; D003711:Demyelinating Diseases / Q000209:etiology* / Q000473:pathology*; D005260:Female; D006509:Hepatitis B / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000009:adverse effects*; D006801:Humans; D008297:Male; D010865:Pilot Projects; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D013997:Time Factors
chemical_list: D017325:Hepatitis B Vaccines