Press Release WHO/67 2 October 1998 NO SCIENTIFIC JUSTIFICATION TO SUSPEND HEPATITIS B IMMUNIZATION On 1 October 1998, the French Ministry of Health announced a decision to suspend routine HB immunization of adolescents in French schools, while continuing the immunization of infants and high risk adults. This decision followed concerns, despite lack of scientific evidence establishing a causal relationship, that Hepatitis B immunization might be linked to the development or flare-up of demyelinating diseases such as multiple sclerosis (MS), and comes in the wake of enormous pressure from anti-vaccine groups. WHO, with the assistance of external experts in neurology, epidemiology, immunology and public health, has carefully reviewed the scientific evidence on whether Hepatitis B vaccine can cause demyelinating diseases such as MS. WHO believes that available scientific data does not demonstrate a causal association between HB immunization and central nervous system diseases, including MS. Over 1 billion doses of Hepatitis B (HB) vaccine have been used since 1981 with an outstanding record of safety and efficacy, and the vaccine is 95% effective in preventing the development of the chronic carrier state of Hepatitis B. HB vaccine is the first vaccine against a major human cancer, as it is the chronic carriers of Hepatitis B who are at a high risk of death from cirrhosis of the liver and liver cancer. Recognizing the enormous value of Hepatitis B vaccine, the World Health Assembly recommended in 1992 that all countries incorporate Hepatitis B vaccine into their routine immunization programmes. To date, 100 countries have added Hepatitis B vaccine into their national immunization programmes, and many industrial countries have begun programmes of immunizing adolescents as well. Although France will continue infant and high risk adult immunization, WHO is concerned that the decision taken yesterday may lead to loss of public confidence in this vaccine, and decisions by other countries to suspend or delay introduction of HB vaccine. There are over 350 million chronic carriers of Hepatitis B at high risk from cirrhosis of the liver and liver cancer. Stopping immunization could see these numbers increase. There have been previous experiences with other vaccines, such as Diphtheria, Tetanus, Pertussis (DTP) vaccine, where unsubstantiated hypotheses and anti-vaccine information lead to loss of public confidence and reduced coverage. Millions of cases of pertussis and hundreds of deaths followed reduced use of DTP in several countries. WHO strongly recommends that all countries already using Hepatitis B vaccine as a routine vaccine in their national immunization programmes continue to do so, and that countries not yet using the vaccine begin as soon as possible. For further information, journalists can contact Gregory Hartl, WHO, Geneva. Telephone (41 22) 791 44 58. Fax (41 22) 791 48 58. E-Mail: hartlg@who.int All WHO Press Releases, Fact Sheets and Features as well as other information on this subject can be obtained on Internet on the WHO home page http://www.who.int