What is hepatitis B?

Hepatitis B is a serious disease that is caused by the hepatitis B virus (HBV) which usually exists in the blood and bodily fluids of the infected (or HBV+) person. The virus infects people of all ages and every year, about 200,000 people are newly infected in the United States. Of this 200,000, 90 percent eventually recover and clear the virus, but over 11,000 will have to be hospitalized and over 20,000 (10 percent) will become chronically (permanently) infected with the virus. About 1.25 million people in the United States have chronic HBV infection, and more than 4,000 people die each year from hepatitis B related liver disease. Before the introduction of the hepatitis B vaccine, over 30,000 children were infected annually, and it is estimated that about a third of our current chronic HBV infections are persons infected either as children or infants prior to the introduction of the hepatitis B vaccine. In fact, the younger a child is at the time of infection with HBV, the greater the likelihood that the child will become chronically infected and be at greater risk for liver disease as an adult.

What is the treatment for hepatitis B?

There is no known cure for hepatitis B. Thus, prevention is the best option to dealing with this disease. Currently, the only Food and Drug Administration (FDA)-approved medicines for treatment of hepatitis B are interferon alpha and lamivudine. Interferon alpha, which is administered via injections, often has side effects, some of which may be severe, and is usually used only for persons whose liver enzyme tests are abnormal. The FDA recently approved Lamivudine in December 1998 for the treatment of chronic hepatitis B in adults. This DNA polymerase inhibitor was originally used for treatment of HIV, and unlike interferon alpha, is available in oral form and appears to have fewer side effects. However, there is a significant risk of viral mutations leading to drug resistance thereby diminishing the drug’s effectiveness. Please consult a physician regarding the therapeutic benefits and side effects of any of these treatments.

What is the hepatitis B vaccine?

The hepatitis B vaccine has been available since 1982. The vaccines currently in use in the United States are made with recombinant DNA technology, and contain protein portions of HBV (usually parts of the outer protein or the surface antigen of HBV). Thus, the vaccines do not contain any live virus. The vaccine is administered intramuscularly in three doses usually given on a schedule of 0,1, and 6 months, but there can be flexibility in this schedule. More than 95 percent of children and adolescents and more than 90 percent of young, healthy adults develop adequate immunity following the recommended three doses. Persons who respond to the vaccine are protected from both acute hepatitis B infections as well as chronic infection.

Who should be vaccinated?

The Advisory Committee on Immunization Practices (ACIP) recommends hepatitis B vaccination for everyone 18 years of age and younger, and for adults over 18 years of age who are at risk for HBV infection, which include:

• Sexually active heterosexual adults with more than one sex partner in the prior 6 months, or have a history of sexually transmitted disease;
• Homosexual and bisexual men;
• Illicit injection drug users;
• Persons at occupational risk of infection;
• Hemodialysis patients;
• Household and sex contacts of persons with chronic HBV infection;
• Clients and staff of institutions for the developmentally disabled.

Why is vaccination recommended for all children as opposed to children living in families where there is the highest risk of HBV infection?

Routine vaccination of all children and adolescents is recommended because a major part of the disease burden of HBV is due to the large number of HBV infections that occur among children. As discussed earlier, a significant number of our chronic carriers of HBV were infected as children and if it were not for the vaccine, over 30,000 children would be infected annually. Most of these infections occur among children of mothers who are not infected with HBV and thus cannot be protected by perinatal hepatitis B prevention programs. Additionally, it is impossible to identify and selectively vaccinate only those children who would be at risk for HBV infection.

While it is true that most HBV infections occur in older adolescents and adults, it has been difficult to reduce the incidence of new HBV infections by selectively vaccinating older adolescents/adults in high-risk groups. In fact, over 30 percent of people infected with HBV have no idea where they might have got their infection! By vaccinating children for hepatitis B, they will now be protected against HBV infection when they become older adolescents and adults.

What are possible serious side effects?

Serious side effects after administration of the hepatitis B vaccine are extremely rare. There have been some anecdotal reports of the association of hepatitis B vaccination with chronic illness such as autoimmune disorders. However, there have been no scientific data supporting these claims. Large-scale immunization exercises have been ongoing in many other countries and in the United States, and thus far there has been no association of hepatitis B vaccination with serious adverse events. No clear association has been demonstrated between hepatitis B vaccination and disorders such as Guillain-Barre syndrome, transverse myelitis, optic neuritis, and seizures. Even then, such alleged associations are still being studied to further ensure the safety of the vaccine. A recent study demonstrated that persons who developed rheumatoid arthritis following hepatitis B vaccination were actually genetically susceptible to rheumatoid arthritis, making it difficult to correlate the occurrence of rheumatoid arthritis with hepatitis B vaccination. Considering the large number of doses of HBV vaccine administered and the very low numbers of serious adverse reactions, it is possible that adverse reactions reported after hepatitis B vaccination may represent coincidence rather than causation.

Finally, as with any vaccination, the risk of anaphylaxis (hives, difficulty breathing, shock) is a real. There is an estimated incidence of about 1 anaphylactic reaction per 600,000 vaccine doses distributed. Thus, further administration of hepatitis B vaccine would be contraindicated (not recommended) for persons who have demonstrated a previous anaphylactic reaction following a previous dose of hepatitis B vaccine.

Any presumed risk of adverse side effects associated with the hepatitis B vaccine must be balanced with the expected 4,000 to 5,000 chronic HBV-related deaths and 30,000 childhood HBV infections that would occur in the absence of HBV immunization. Given the frequency and severity of hepatitis B infection, the benefits of vaccination far outweigh the known and potential risks.