Hepatitis B immunization for children

Hepatitis B is a viral infection of the liver that sometimes becomes chronic. Eventually, it may lead to liver failure or liver cancer. Hepatitis B is a major health problem in the United States. More than 5,000 people die each year from illnesses related to hepatitis B. The risk of developing a serious infection is higher for young children than adults. Only 10 percent of new hepatitis B infections occur in infants and young children. However, one-third of those who develop chronic hepatitis B acquired the infection at a young age.

Hepatitis B spreads through exposure to fresh or dried infected blood or body fluids (such as semen, saliva and vaginal fluids). Often, the infected person has no symptoms and is unaware he or she is carrying the virus. People who are involved in activities or occupations that include exposure to blood or body fluids are at high risk for developing hepatitis B. However, as many as 30 percent of those who develop the disease have no identified risk factors. Hepatitis B also can spread from an infected mother to her baby, most commonly during birth.

The hepatitis B vaccine is an inactivated vaccine, which means that it contains a dead form of the hepatitis B virus. The vaccine has been used in the United States since 1981. It originally was recommended for those at high risk of developing the illness. However, this approach had little effect on the number of new cases that continued to develop each year. In 1991, the recommendations were revised to include routine immunization of all infants.


Recommendations/dose
The hepatitis B immunization schedule will vary, depending on your child's risk of developing the infection and age, and also the type of vaccine used. But, the typical immunization schedule is three doses. It's important that the first dose be given at birth, the next at ages 1 month to 2 months, and the third at ages 6 months to 18 months. (An extra dose may be given if a combination vaccine is used after the first dose. In this case, the typical schedule may vary slightly, depending on which combination vaccine is used.) Other recommendations are as follows:
If the mother tests negative for hepatitis B, the schedule is as above.

If the mother has hepatitis B or is a carrier of the virus:
the first dose is given within 12 hours of birth, along with the hepatitis B immune globulin
the second dose is given at ages 1 month to 2 months
the third dose is given at age 6 months

If the mother's hepatitis B status unknown:
the first dose is given within 12 hours of birth and the mother is tested for hepatitis B
if she tests positive, the baby will receive the hepatitis B immune globulin as soon as possible (no later than one week after birth) the second dose is given at age 1 to 2 months and the third at age 6 months
if the mother tests negative, the routine schedule for hepatitis B vaccine is followed
Remember, an extra dose may be given if a combination vaccine is used after the first dose given at birth. The schedule may vary slightly, depending on which combination vaccine is used.

All children should receive the vaccine by or before ages 11 years to 12 years.

For older children, the second dose is given one to two months after the first. And, the third dose is given four to six months after the first.

Children ages 11 years to 15 years can receive two larger doses of Merck's RecombivaxHB vaccine instead of three, with the second dose given four to six months after the first.

Young adults can receive the three-dose series at any time. The hepatitis B vaccine is especially important for young adults at high risk for contracting hepatitis B, including males who have sex with males and those who:

have multiple sexual partners
have a sexually transmitted disease
inject illegal drugs
are long-term male prison inmates
are routinely exposed to blood, blood products or human bites (such as health care workers or military personnel)
live or work in an institution for the developmentally disabled
live in, travel to or emigrated from a region of the world where hepatitis B is prevalent
are household members (including those with a child adopted from a foreign country) or sexual contacts of someone who's infected with hepatitis B
receive clotting factors for a blood clotting disorder
receive hemodialysis
If the interval between doses described above is longer than recommended, the child won't have to start the series over or receive extra doses. If the interval between doses is less than recommended, that particular shouldn't be counted as part of series.


Blood testing
It's recommended that babies born to mothers who have hepatitis B or are carriers of the virus have certain blood tests done once the vaccination series is completed. The hepatitis B surface antigen (HbsAg -- a protein found in the outer covering of the hepatitis virus) indicates that the baby is a chronic carrier of hepatitis B. The hepatitis B surface antibody (HbsAb -- one of the body's defenses against the hepatitis B virus) appears about four weeks after the hepatitis B surface antigen disappears. The presence of the antibody means the vaccine is now protecting the baby from hepatitis B.

Effectiveness/booster
After three injections, the vaccine provides 80 to 100 percent protection from hepatitis B. The length of protection is uncertain, but appears to be more than 15 years. A booster isn't currently recommended.

Side effects
Side effects are uncommon. If they do occur, they're usually minor and include soreness, redness, warmth or swelling at the injection site; low-grade fever; fatigue; headache; and irritability. Side effects typically begin within 24 hours and usually disappear within 48 to 72 hours. Allergic reactions are possible, but rare.

Who should wait to get the vaccine?
Your child's doctor may postpone this vaccine if your child has a moderate to severe acute illness.

Who shouldn't get the vaccine?
Your child shouldn't get this vaccine if he or she has had a serious reaction or allergy to a prior hepatitis B vaccination or baker's yeast