WASHINGTON (Reuters Health) May 31 - There is no hard link between
hepatitis B vaccination and later development of multiple sclerosis (MS) and other
neurological diseases in adults, a federally funded scientific panel concluded in a report
released Thursday.
"Evidence favors rejection of a causal relationship between hepatitis B vaccine
administered to adults and incident multiple sclerosis," states the report, released
by the Institute of Medicine (IOM). The vaccine also does not appear to be implicated in
causing symptom relapses in people with mild MS, it states.
The panel also said that not enough evidence exists to connect the vaccine with
neurological diseases in infants. The group recommended further studies of the disorders
in vaccinated children, but called for no review of current national immunization
policies.
The hepatitis B vaccine has been a part of the routine infant immunization schedule in
the US since 1991. Many adults--including healthcare workers and those traveling to
regions with high levels of the disease--have received the vaccine in its current form
since the late 1980s.
Some consumers' groups and a few lawmakers have voiced concerns that the vaccine
increases the risk for some neurological diseases. Medical case reports have suggested
that some children who receive the vaccine go on to develop neurological disorders like
transverse myelitis or Guillain-Barre syndrome.
"Hopefully our report will ease the concerns of adults who need to be immunized
against hepatitis B and are worried about the risk for multiple sclerosis," said Dr.
Marie C. McCormick, head of the department of maternal and child health at Harvard
University and the chair of the IOM immunization safety review committee.
Thursday's report acknowledged some theoretical concern that the vaccine could trigger
demyelination in the nervous system. But available evidence shows no connection between
the vaccine and demyelination disorders, the experts concluded. In one study, 7.7% of
nearly 400 adults diagnosed with MS between 1995 and 1999 had received the vaccine before
their diagnosis. An equal percentage of similar adults without MS had also received the
vaccine, suggesting that the immunizations were not contributing to increased MS rates.
Still, relatively few studies looking at a possible link between hepatitis B
vaccination and other demyelination diseases have been performed. Panelists concluded that
they had "inadequate" evidence to accept or reject a hard connection to other
less common disorders.
The committee recommended improved surveillance of all healthcare workers who received
the vaccine since 1991 and that government and private health organizations work to ease
the public's fears about vaccine safety.
"The committee is concerned that the public's need for relevant information is not
being effectively met," the report concludes.