Immunization with the synthetic hepatitis B vaccine may be associated with an increased risk of developing multiple sclerosis, according to review of a UK database.

Even if this is so, “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, at Harvard School of Public Health in Boston, and his associates write in the medical journal Neurology.

Hepatitis B vaccine is considered one of the safest vaccines ever produced, Hernan’s team points out. Several studies that have looked for a connection between hepatitis B vaccination and multiple sclerosis (MS) have failed to find one.

However, because of limitations of those studies, the team conducted another study using the General Practice Research Database in the UK.

One hundred sixty-three patients had been included in the database for at least three years before their first MS symptom were diagnosed. These people were matched by age, gender, and time of database entry to 1604 “control” subjects.

Eleven MS patients (6.7 percent) had been vaccinated against hepatitis B compared with 39 control subjects (2.4 percent). The researchers conclude that hepatitis B vaccination was associated with a 3-fold increase in incidence of MS over three years.

However, Hernan’s group emphasizes that 93 percent of the MS 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 hepatitis B vaccination and MS, the two editorialists from Washington University in St. Louis argue that “the data presented do not provide proof of an association sufficient to implement policy changes with regard to immunization programs.”

SOURCE: Neurology, September 14, 2004.