Clinical

Engerix B vaccine may be linked to pediatric CNS inflammatory demyelination

Last Updated: 2009-03-20 18:12:18 -0400 (Reuters Health)

By Scott Baltic

NEW YORK (Reuters Health) - Although hepatitis B vaccination does not appear to generally increase the risk of central nervous system (CNS) inflammatory demyelination in childhood, a recent French study reported in the March issue of the journal Neurology suggests Engerix B vaccine may be associated with such conditions, particularly multiple sclerosis (MS).

When the researchers considered only those participants (of a total of more than 3,000) who were compliant with guidelines for vaccinations in early childhood, exposure to a hepatitis B vaccine more than 3 years earlier was associated with a trend towards increased risk of CNS inflammatory demyelination (odds ratio 1.50), and to MS (OR 1.73), specifically.

"The OR was particularly elevated for (Engerix B vaccine) in patients with confirmed MS," Dr. Yann Mikaeloff of Assistance Publique-Hopitaux in Paris and associates report.

Compliance with vaccination guidelines was defined primarily as at least one dose of Bacille Calmette-Gu�rin (BCG) vaccine, one mumps-rubella-measles vaccine, and four doses of diphtheria-tetanus-poliomyelitis vaccine during the first 2 years of life.

In this population-based, case-control study, the cases were French-born patients with a first episode of acute CNS inflammatory demyelination that occurred between 1994 and 2003 and before the patient was 16 years of age.

Within this group of 349 cases, 198 experienced single episodes (without relapse) of acute disseminated encephalomyelitis, isolated optic neuritis, isolated transverse myelitis, brainstem dysfunction or related syndromes. The remaining 151 developed MS, as confirmed by at least one additional episode.

These cases were matched with up to 12 controls by age, sex and residence. A family history of MS was significantly more common in the cases (2.3%) than in the controls (1.1%).

Of the overall 349 case patients, 154 (44.1%) had received at least one hepatitis B vaccination. In the 3 years before the index date, 24.4% of the cases and 27.3% of the matched controls received a hepatitis B vaccination. Furthermore, shorter or longer time frames, the number of hepatitis B vaccinations, or the brand of vaccine was associated with a higher risk of CNS inflammatory demyelination.

However, a subgroup analysis indicated that exposure to the Engerix B vaccine more than 3 years before the index date was associated with an adjusted OR of 1.50 for CNS inflammatory demyelination and 2.40 for confirmed MS.

Neurology 2009;72:873-880.