Epidemiology

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 Neurology.

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."

Neurology 2004;63:772-773,838-842.