Hepatitis B is a liver disease caused by the hepatitis B virus (HBV). According to the World Health Organization (WHO), approximately 30 percent of the world's population has evidence of infection with HBV. In the United States, approximately 5 out of 100 people get HBV infection at sometime in their lifetimes, if not vaccinated. Hepatitis B vaccine protects against hepatitis B and has been available since 1982. WHO recommends the hepatitis B vaccine for all children.
Target Audience
The primary routes of spread of HBV include from mother to baby, from child to child, through unsafe injections and blood transfusions and through sexual contact.
Besides all children, the Centers for Disease Control and Prevention recommends that hepatitis B vaccine be given to people at increased risk of getting hepatitis B. This includes health care personnel, laboratory workers handling blood, police, firemen, hemophiliacs, people in intimate contact with hepatitis B carriers, individuals with multiple sex partners, homosexuals, prostitutes, intravenous drug abusers, and people traveling to high-risk areas.
Schedule
Hepatitis B vaccine causes production of hepatitis B antibodies in the body, which protect against infection from hepatitis B virus. For adults, the vaccine is usually given in a course of 3 injections at zero, 1, and 6-month intervals. For children, the schedule is flexible, and clinicians usually incorporate hepatitis B vaccination into an existing childhood immunization schedule such as at the same time as the three doses of diphtheria-tetanus-pertussis vaccine.
Effective
According to a report published by the Immunization Action Coalition, at least 9 out of 10 healthy young adults and more than 9 out of 10 infants, children, and adolescents develop protective antibodies and subsequent immunity to HBV infection after 3 doses of vaccine. Some people opt for a blood test to check if they have produced enough antibodies to ensure protection. Some people may need an extra dose. Very small numbers of people will not respond to the vaccine.
According the "New York Times," hepatitis B vaccine is 95 percent effective in preventing HBV infection and its chronic consequences, and is the first vaccine against a major human cancer.
Safety and Side Effects
Since 1982, an estimated 70 million adolescents and adults, and 50 million infants and children have received at least one dose of hepatitis B vaccine in the United States. Hepatitis B vaccines have been shown to be safe in infants, children, adolescents and adults. The majority of children who receive this vaccine have no side effects. However, the hepatitis B vaccine may cause mild reactions such as irritation, redness, swelling, warmth, itching, bruising or pain at the injection site. Fewer than 1 out of 3 children experience a mild reaction. Other side effects include headache, weakness, fatigue, sore throat, low-grade fever, nausea, dizziness, flu-like symptoms and general body discomfort. Adults are slightly more likely to experience more mild side effects than children. Serious allergic reactions following hepatitis B vaccination are rare.
Site of Administration
Hepatitis B vaccine is recommended to be given via the muscle. The thigh muscle is the preferred site of administration for infants, 12 months of age and younger. For children who are a little older, either the thigh or the upper arm muscle can be used. The preferred site of administration for adolescents and adults is the upper arm muscle.
Engerix-B and Recombivax HB
The only hepatitis B vaccines available in the United States are Engerix-B and Recombivax HB. Both are produced by genetic engineering, or recombinant DNA technology. A gene responsible for surface protein of a hepatitis B virus is inserted into Baker's yeast, causing the production of antigens, which are collected and purified and made into a vaccine. Antigens stimulate the body to produce antibodies that protect against HBV when it attacks the body. Because only surface antigens of the virus are manufactured, it is impossible to get HBV infection from the vaccine.
Hepatitis B vaccine is also made in combination with other vaccines in the United States. A combination vaccine called Twinrix that contains Engerix-B and a hepatitis A vaccine is also available.
