Whether they are caused by or coincidental to the vaccination requires further study. Such reports do not mean that the vaccine is unsafe for the population, however, since millions of persons have received the vaccine without problem. While reported, there is no confirmed scientific evidence that hepatitis B vaccine causes chronic illness, including multiple sclerosis, chronic fatigue syndrome, rheumatoid arthritis, or autoimmune disorders. There is no risk of HBV infection from the vaccine. Large-scale hepatitis B immunization programs in Taiwan, Alaska, and New Zealand have observed no association between vaccination and the occurrence of serious adverse events.
Additional evaluations are ongoing.
Although none of the persons who developed anaphylaxis died, anaphylactic reactions can be life-threatening, and therefore further vaccination with hepatitis B vaccine is contraindicated in persons with a history of anaphylaxis after a previous dose of vaccine. Studies are in progress to better quantify the possible slight risk of hair loss. Any presumed risk of adverse events associated with hepatitis B vaccination must be balanced with the expected 4,000 to 5,000 HBV-related liver disease deaths that would occur without immunization, assuming a 5 percent lifetime risk of HBV infection. The scientific evidence to date does not support hepatitis B vaccination causing MS or other demyelinating diseases. Eventually, in most patients, remissions do not reach baseline levels and permanent disability and sometimes death occurs.