Questions & Answers
Hepatitis B - The Vaccine
Back to Parent Q&A Category Back to All Hepatitis B Q&A Back to All Q&A Back to Hepatitis B


  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.