|
- 现金
- 222032 元
- 精华
- 285
- 帖子
- 67620
- 注册时间
- 2001-11-10
- 最后登录
- 2023-5-7
|
1楼
发表于 2002-6-5 18:04
Hepatitis B, Nerve Diseases Not Linked: U.S. Report
Thu May 30, 5:21 PM ET
By Todd Zwillich
WASHINGTON (Reuters Health) - 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.
The panel also said that not enough evidence exists to connect the vaccine with neurological diseases in infants given the shot. The group recommended further studies of the disorders in vaccinated children, but called for no review of current national immunization policies.
"Evidence favors rejection of a causal relationship between hepatitis B vaccine administered to adults and incident multiple sclerosis," states the report, released Thursday by the Institute of Medicine (news - web sites) (IOM).
The vaccine also does not appear to be implicated in causing symptom relapses in people with mild MS, it states.
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.
Both disorders result in muscle weakness and loss of reflexes. An increased risk of Guillain-Barre was linked to the 1976 vaccine against swine flu.
Patients' concerns have also worried physicians, who fear that vaccine fears may be steering parents and at-risk adults away from obtaining protection against hepatitis B. The disease is transferred via contact with bodily fluids, including blood and semen, and is a leading cause of cirrhosis and liver cancer.
"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 help trigger a process called demyelination in the nervous system. The process leads to the breakdown of the fat-like insulation surrounding nerves. That breakdown is a root cause of MS and other disorders such as optic neuritis because it causes disruptions in the transmission of nerve signals.
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.
Tue Jun 4, 1:33 PM ET - (Reuters)
|
|
