Reuters Health Information (2004-09-13): Hepatitis B vaccine linked with increased MS risk
Hepatitis B vaccine linked with increased MS risk
Last Updated: 2004-09-13 16:00:26 -0400 (Reuters Health)
NEW YORK (Reuters Health) - Immunization with the
recombinant hepatitis B vaccine may be associated with an increased
risk of multiple sclerosis, according to review of a database that
prospectively tracks healthcare utilization in the UK.
Nevertheless, "any decision concerning hepatitis B vaccination needs
to take into account the large benefits derived from the prevention of
a common and potentially lethal infection," lead author Dr. Miguel A.
Hernan, an epidemiologist at Harvard School of Public Health in Boston,
and his associates write in their report in the September 14th issue of
Hepatitis B vaccine (HBV) is considered one of the safest vaccines
ever produced, Dr. Hernan's team points out. Several studies that have
looked for a connection between HBV and MS have failed to find one. But
because of methodologic limitations of those studies that may have
influenced their conclusions, the team conducted a nested case-control
study using the General Practice Research Database in the UK.
One hundred sixty-three patients who had been included in the
database for at least 3 years prior to their first symptom (index date)
were diagnosed with MS between 1993 and 2000. The 1604 control subjects
were matched by age, gender, and time of database entry.
Eleven (6.7%) MS patients were vaccinated in the 3 years before the index date, compared with 39 (2.4%) of control subjects.
The authors estimate that HBV immunization was associated with a 3-fold increase in incidence of MS within the next 3 years.
However, Dr. Hernan's group notes, there was no increased risk if
the date of diagnosis of MS was the index date, nor was there increased
risk with a greater number of immunizations. They also emphasize that
93% of the cases had never been vaccinated against hepatitis B.
In a journal editorial, Drs. Robert T. Naismith and Anne H. Cross
comment that "the question remains as to whether these 11 cases of MS
can be generalized to the population at large."
Given the number of studies and expert panels that have found no
link between HBV and MS, the two editorialists from Washington
University in St. Louis urge that "this article should be viewed as
another piece of the puzzle of MS causation, but the data presented do
not provide proof of an association sufficient to implement policy
changes with regard to immunization programs."