Hepatitis B Vaccination FAQ for Researchers

Hepatitis B virus is transmitted between people by direct blood-to-blood contact or semen and vaginal fluid of an infected person and is also an occupational risk for individuals with potential for exposure to human blood, body fluids, tissues, and cells.

Modes of transmission are the same as those for the human immunodeficiency virus (HIV), but the Hepatitis B virus is 50 to 100 times more infectious. Unlike HIV, the Hepatitis B virus can survive outside the body for at least 7 days. During this time, the virus can still cause infection if it enters the body of a person who is not protected by the vaccine.

A safe and effective vaccine against Hepatitis B has been available since 1982 and is the first vaccine against a major human cancer.

If a protective antibody response develops after vaccination, vaccine recipients are virtually 100% protected against clinical illness. After administration of the 3-dose Hepatitis B vaccination series, more than 90% of healthy adults age 40 years or younger develop adequate antibody responses. After age 40, the proportion of persons who have a protective antibody response to vaccination begins to decline below 90%, and by age 60 years, protective levels of antibody develop in only 75% of vaccinated persons.

Hepatitis B vaccination is strongly recommended for employees who have occupational exposure to bloodborne pathogens (BBP).

• See Bloodborne Pathogens Program for more information.
• See Vaccination for Researchers and Research Support Staff for more information. 

If you are at risk for occupational exposure to Hepatitis B Virus (HBV) and you cannot provide documentation of receiving 3 doses of Hepatitis B vaccine in the past, the recommendation is to repeat vaccination with the complete 3-dose vaccination series, with post-vaccination antibody titer testing 1 to 2 months after the third dose.

If at all possible, you should contact the medical facility where you received your Hepatitis B vaccination to request a copy of your vaccination record. Contact the COEM EH&S Occupational Health Nurse if you have questions.

Although a positive Hepatitis B antibody (anti-HBs) titer indicates that you were immune at the time you were tested, this result does not accurately reflect long-term immunity. Long-term immunity has been shown only for persons attaining an adequate anti-HBs titer result (≥10 mIU/mL) 1 to 2 months after completing a 3-dose vaccination series.

The Centers for Disease Control and Prevention (CDC) does not recommend using a positive anti-HBs titer as verification of immunity for an individual who cannot provide documentation of receiving 3 doses of hepatitis B vaccine in the past. For individuals without documentation of previous vaccination, the CDC's Advisory Committee on Immunization Practices (ACIP) recommends following the procedure outlined above.

Post-vaccination testing (anti-HBs) should only be done 1 to 2 months after the last dose of Hepatitis B vaccine. If adequate anti-HBs (≥10 mIU/mL) is present, then no further testing needs to be done. Studies indicate that immunologic memory remains intact for more than 25 years and confers protection against HBV infection even though anti-HBs levels might become low or decline below detectable levels over time.

No. It is not necessary to restart the series or add doses because of an extended interval between doses. The Hepatitis B vaccine series can be continued from where it was stopped.

The usual schedule for adults is 2 doses separated by no less than 4 weeks, and a third dose 4 to 6 months after the second dose. If an accelerated schedule is needed, the minimum interval between the first 2 doses is 4 weeks, and the minimum interval between the second and third doses is 8 weeks. However, the first and third doses should be separated by no less than 16 weeks. Doses given at less than these minimum intervals should not be counted as part of the vaccination series.