Questions & Answers
Hepatitis B - The Vaccine
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  1. How can hepatitis B be prevented?

    If hepatitis B vaccine is administered before infection, it prevents the disease and the carrier state in almost all individuals.

    The hepatitis B vaccine can provide protection in 90% to 95% of healthy young adults. The vaccine can be given safely to infants, children, and adults, usually in three doses over a 6-month period. Even pregnant women can be safely given these shots, if their risk factors warrant it. Hepatitis B shots are very safe, and side effects are rare. Hepatitis B vaccine is that first vaccine that prevents cancer—liver cancer.

  2. How safe and effective is the vaccine?
    Hepatitis B vaccine has an outstanding record of safety and effectiveness. Studies have shown that the vaccine is 95% effective in preventing children and adults from developing chronic infection.

  3. What are the risks from hepatitis B vaccine?
    A vaccine, like any medicine, is capable of causing serious problems, such as severe allergic reactions. The risk of hepatitis B vaccine causing serious harm or death is extremely small. Getting hepatitis B vaccine is much safer than getting hepatitis B disease.

  4. Who should get immunized?
    • All babies, at birth
    • All children 0 to 18 years of age who have not been immunized
    • People of any age whose behavior puts them at high risk for hepatitis B infection
    • People whose job exposes them to human blood

  5. If there is a moderate or severe reaction, what should I do?
    Any unusual condition, such as a serious allergic reaction, high fever or unusual behavior should be reported to your health care provider. Serious allergic reactions are extremely rare with any vaccine. If one were to occur, it would be within in a few minutes to a few hours after the shot. Signs can include difficulty breathing, hoarseness or wheezing, hives, paleness, weakness, a fast heart beat or dizziness. If any of these symptoms occur, you should seek immediate medical attention, then explain the details of the event to your doctor and ask them to report the event to the Vaccine Adverse Event Reporting System (VAERS,

  6. At what age are hepatitis B shots routinely given?
    In the U.S., hepatitis B shots are routinely recommended for all children 0 to 18 years of age. For babies, the first hepatitis B shot is recommended to be given in the hospital just after birth. Older children and teens should be immunized at the earliest opportunity. Any adult who is at risk for hepatitis B infection should start the vaccine series right away.

  7. Where can I get hepatitis B shots?
    At any military immunization clinic. In the private sector, Tricare and children's health insurance often cover the cost of this vaccine. If a child is uninsured, ask your local health department for assistance. For adults, contact the healthcare provider first, to find out if the vaccine is covered under the health plan. For people who are uninsured, call your local health department for advice.


  1. How many shots are needed?
    Usually three shots are needed for the best protection against hepatitis B, but some protection is provided from receiving as little as one dose. The shots are usually given on a schedule of 0, 1, and 6 months, but there is flexibility in the timing of these injections. As with other vaccines, if one falls behind on the schedule, just continue from where you left off. Hepatitis B shots will not help or cure a person who is already infected with the hepatitis B virus.

  2. How is the vaccine administered?
    A recombinant vaccine is used to prevent hepatitis B. The vaccine is given in a three-dose series (0, 1 and 6 months), injected into the muscle (intramuscularly) into the upper thigh of an infant or the deltoid muscle of an adult.

  3. For how long is hepatitis B vaccine effective?
    Long-term studies of healthy adults and children indicate that hepatitis B vaccine protects against chronic hepatitis B infection for at least 15 years, even though antibody levels might decline below detectable levels.

  4. Are booster doses of hepatitis B vaccine needed?
    No, booster doses of hepatitis B vaccine are not recommended routinely. Data shows that vaccine-induced hepatitis B surface antibody (anti-HBs) levels might decline over time. But immune-cell memory remains intact indefinitely after immunization. People with declining antibody levels are still protected against clinical illness and chronic disease.

  5. If my hepatitis B immunization series is interrupted, do I have to start over?
    No. If the immunization series is interrupted, resume with the next dose in the series.

  6. Do I have to re-start the hepatitis B series if I am late in getting a dose?
    No. If you are late getting a vaccine dose, you do not have to restart the series or get extra doses. As with other vaccines, if you fall behind, just continue from where you left off. Longer times between doses do not make the vaccine less effective. It is best, however, to get your delayed doses as soon as possible to make sure that you are protected against the disease.

  7. I have completed the hepatitis B vaccine series more than once, but my labs still show that I am susceptible to hepatitis B disease. Should I repeat the series?
    Some people do not respond to hepatitis B vaccination. They are called "non-responders." There are specific guidelines for steps to take with non-responders who do not show positive lab tests. Non-responders should be counseled that they may be susceptible to hepatitis infection and certain precautions should be taken. More information is available at You also may contact a IHB healthcare provider if you have questions.


  1. Are there any contraindications to hepatitis B vaccine?

    Some people should not get hepatitis B vaccine or should wait.

    People should not get hepatitis B vaccine if they have ever had a life-threatening allergic reaction to baker’s yeast (the kind used for making bread) or to a previous dose of hepatitis B vaccine.

    People who are moderately or severely ill at the time the shot is scheduled should wait until they recover before getting the hepatitis B vaccine.

  2. Where can I receive more information about hepatitis B?

    Contact your local and state health departments for more information. You can also contact the following organizations:

  3. Sources

    CDC Hepatitis B:

    CDC Vaccine Information Statement:

    Immunization Action Coalition:

    World Health Organization:

    Developed in cooperation with the Immunization Action Coalition and the Centers for Disease & Control and Prevention (CDC).