 Does
Hepatitis B Vaccination Raise the Risk of Multiple Sclerosis?
Hepatitis
B virus (HBV) is
highly preventable with a vaccine, which is recommended
as a routine immunization for infants, as well as for adults at risk, including
men who have sex with men, sexually active individuals with multiple partners,
injection drug users, healthcare and public safety workers, people
with HIV or with other types of chronic liver
disease (including hepatitis C), and travelers to regions with a high hepatitis
B prevalence.
There are 2 FDA-approved hepatitis B vaccine brands available,
Engerix-B and
Recombivax
HB; there is also a combination hepatitis A and B vaccine called Twinrix.
Some
people are hesitant to receive the vaccine due to a fear of side effects. Among
these is multiple sclerosis, a disease that involves the loss of myelin, the fatty
covering that facilitates conduction in neurons. Various studies have suggested
a link between demyelinating diseases and the HBV vaccine, but others have found
no such association.
Yann Mikaeloff from INSERM in Paris in colleagues
conducted a population-based case-control study of the association between inflammatory
demyelination and HBV vaccination in children; results were published in the October
8, 2008 advance online edition of Neurology.
The 349 case patients
were children (under age 16) in France who experienced a first episode of acute
central nervous system (CNS) inflammatory demyelination between 1994 and 2003.
Each case patient was matched on the basis of age, sex, and geographical location
with up to 12 control subjects randomly selected from the general population.
Information on vaccinations was confirmed by a copy of vaccination certificates.
The odds ratios (OR) of CNS inflammatory demyelination associated with hepatitis
B vaccination were estimated using conditional logistic regression.
Results
•
The rates of hepatitis B vaccination in the 3 years before the start of the study
were 24.4% for the 349 case patients with demyelination and 27.3% for the 2941
matched control subjects.
•
Hepatitis B vaccination during this period was not associated with an increase
in the rate of CNS inflammatory demyelination (adjusted OR 0.74).
•
There was no significant association as a function of the number of injections
or HBV vaccine brand.
•
However, when the analysis was restricted to subjects compliant with vaccination,
vaccine exposure more than 3 years before the study was associated with a trend
toward an increased risk of demyelination (OR 1.50).
•
This elevation in risk was essentially attributable to the Engerix B vaccine (OR
1.74).
•
The risk was particularly elevated for this brand in patients with confirmed multiple
sclerosis (OR 2.77).
"Hepatitis
B vaccination does not generally increase the risk of CNS inflammatory demyelination
in childhood," the study authors concluded. However, they added, "the
Engerix B vaccine appears to increase this risk, particularly for confirmed multiple
sclerosis, in the longer term."
"This association cannot be taken
as confirmation that the vaccine caused MS," according to a media statement
issued by the American Academy of Neurology, which publishes the journal. "Further
studies are needed to determine whether this is a causal relationship."
Assistance
Publique-Hôpitaux de Paris, Service de Neurologie Pédiatrique and
Centre de Référence National des Maladies Inflammatoires du Cerveau
de l'Enfant, INSERM U822, and INSERM U802, Hôpital Bicêtre, Université
Paris Sud 11, Le Kremlin Bicêtre, France; Division of Clinical Epidemiology,
McGill University and Royal Victoria Hospital, Montreal, Canada.
10/10/08
Reference
Y
Mikaeloff, G Caridade, S Suissa, and others. Hepatitis B vaccine and the risk
of CNS inflammatory demyelination in childhood. Neurology. October 8, 2008
[Epub ahead of print]. (Abstract).
Other
source
American Academy of Neurology. Majority of Children Vaccinated Against
Hepatitis B Not at Increased Risk of MS. Press release. September 25, 2008. |
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