Hepatitis B:

About 2 billion people have been infected with the hepatitis B virus (HBV) worldwide, and each year 1 million people die, mostly due to cirrhosis and liver cancers that develop in the chronic form of this disease. In the U.S., about 1.25 million people have chronic hepatitis B.

Hepatitis B is also known as serum hepatitis. It spreads through blood and sexual contact. The infection is seen with increased frequency among intravenous drug users who share needles and among the homosexual population. This photograph is an electronmicroscopic image of hepatitis B virus particles. (Courtesy of the CDC.)

Pregnant women with hepatitis B can transmit the virus to their babies. Even if they are not infected at birth, unvaccinated children of infected mothers run a 60% risk of developing hepatitis B before age 5. Although hepatitis B infections have dropped 95% since routine immunization began in the early 1990s, there are still children who aren't immunized, and the disease persists. Universal vaccination against this disease during childhood is very important.

Vaccine for Hepatitis B

Several inactivated virus vaccines, including Recombivax HB, GenHevac B, Hepagene, and Engerix-B, can prevent hepatitis B. Twinrix is a vaccine against both hepatitis A and B. They are safe, even for infants and children. Vaccination programs are proving to reduce the risk for liver cancer.

Hepatitis B Vaccine for Early Childhood. Experts now recommend that all infants and children not previously vaccinated be immunized by the time they reach seventh grade. Typical schedules for hepatitis B vaccinations in childhood are as follows:

• All infants should receive the hepatitis B vaccine soon after birth and before hospital discharge. (The first dose may be delayed if the mother has no evidence of infection, but only with the doctor's permission.) The second dose should be given at 1 - 2 months; and the third between 6 and 18 months (at least 16 weeks after first dose and 8 weeks after second dose). (A fourth dose may also be given if any of the previous doses was a combination vaccine.) This is a safe vaccine, even in newborns, and parents should be sure their infants are immunized.
• Infants of mothers infected with hepatitis B should be treated with immune globulin plus the hepatitis vaccine within 12 hours of birth. The second dose should be given at 1 - 2 months and the third at 6 months. Infants should be tested for antibody status at 9 - 18 months to see if they are chronic virus carriers or need to be revaccinated. Immunization rates are still too low in this group.
• When it is not known if a mother is infected, the infant should receive the vaccine within 12 hours of birth. The mother's blood should then be tested right away. If she is infected, the infant should receive immune globulin within 1 week of birth.
• Children who are 11 - 12 and who have not been immunized should receive 2 or 3 doses of the vaccine (depending on the brand) given over a few months.

Hepatitis B vaccine protection may wane over time. According to a 2007 study, 40% of adolescents who had received a first dose of the vaccine as newborns had declining immunity to the disease by age 14. As of now, routine booster shots are not recommended because more research is needed on the subject. Booster shots may be recommended for those at risk, such as from sexual exposure.

Hepatitis B Vaccine for Adults. The following adults are at very high risk and should be vaccinated:

• Health care and public safety workers who may be exposed to blood products. Such individuals have a risk for hepatitis B that ranges from 15 - 30%.
• People in the same household as hepatitis B-infected individuals. (Unvaccinated people who have had intimate exposure to people with hepatitis B may be protected with immune globulin, which is sometimes administered with the vaccine.)
• Travelers to countries with a high incidence of hepatitis B infection.
• Patients who require transfusions and have not been infected with hepatitis B. (Those with blood clotting disorders should have the vaccination administered under the skin, not injected in the muscle.)
• Sexually active individuals with multiple partners.
• People with any sexually transmitted diseases.

Other people at risk who would benefit from vaccinations include:

• Patients and workers in mental institutions
• Morticians
• Patients undergoing hemodialysis (these people may need larger doses or boosters; they also may need to be revaccinated if blood tests indicate they are losing immunity)
• People who use injected drugs
• Pregnant women at risk for the virus (there is no evidence that the vaccine is dangerous to the fetus)
• People receiving treatments or who have conditions that suppress the immune system may need the vaccination, although its benefits for this group are unclear except for those at high risk, such as people with HIV or spleen abnormalities.

The regimen in adults is typically 3 doses given over 6 months. One study reported that older adults would benefit from a fourth dose without incurring serious side effects. People who abuse alcohol may need higher doses.

A small percentage of people do not develop immunity, even after a vaccine has been given repeatedly. A more potent vaccine is proving to be effective for these people; it loses its effect after 5 years in about one-third of those who receive it.

Side Effects of Hepatitis B Vaccine

Soreness. Soreness at the injection site is the most common side effect.

Nerve Inflammation. There have been reports of nerve inflammation after vaccinations for hepatitis B, and some questions about multiple sclerosis. However, studies and reviews have found no real evidence linking the vaccine to a number of disorders.

Due to even the small theoretical risk of nerve damage in infants, some groups oppose the vaccination in children who are not in high-risk groups. However, this risk must be balanced against the significant reduction in chronic hepatitis and liver cancer cases due to this vaccine, especially around the world. [For more information see In-Depth Report #59: Hepatitis.]