Responding to HBV Exposures in Health Care Settings

The following are guidelines for people exposed to HBV inside a health care facility. These are considered occupational settings.

• The recommendation for vaccinated clinicians depends on their vaccination and serological test results. Protection of exposed clinicians depends on confirmation of vaccine uptake and testing status.
• The recommendation for unvaccinated or incompletely vaccinated clinicians depends on the HBsAg testing status of the source patient they are exposed to.

• Some people will not respond to HepB vaccines. These patients should receive HBIG as soon as possible.
• Clinicians who are susceptible to HBV infection should receive both HepB vaccine and HBIG as soon as possible.

The following guidelines are for people exposed to HBV* in places outside a health care facility. These are considered non-occupational settings.

For cases in which the source patient is known HBsAg positive, please adhere to the following guidelines:

• If you have been vaccinated but have not had post-vaccination testing, you should receive a single dose of HepB vaccine after exposure.
• If you are vaccinated and had post-vaccination testing that confirms anti-HBs levels >=10mlU/ml^ǂ indicating adequate immunity, no further treatment is necessary.
• If you are exposed in the process of being vaccinated, you should receive a dose of hepatitis B immune globulin (HBIG) and complete the full HepB vaccine series (it is not necessary to restart the vaccination series).
• If you are not vaccinated or don't know if you were ever vaccinated, you should receive both HBIG and HepB vaccine as soon as possible after exposure (preferably within 24 hours).

For cases in which the source patient's HBsAg status is unknown, please adhere to the following guidelines:

• If you have been vaccinated with written documentation of a complete HepB vaccine series, you do not require any further treatment
• If you are exposed in the process of being vaccinated, you should complete the full HepB vaccine series (it is not necessary to restart the vaccination series).
• If you are not vaccinated or don't know if you were ever vaccinated, you should receive the HepB vaccine series with the first dose administered as soon as possible after exposure (preferably within 24 hours).

For additional information and guidelines, see the University of Washington's resource on Occupational HBV Postexposure Prophylaxis.

FOOTNOTES:

*Through a distinct, identifiable exposure to blood or body fluids that contain blood.

ǂ Anti-HBs levels of ≥10 mIU/mL are generally considered seroprotective; however, different assays have different assay cutoff values based on which reported levels of anti-HBs might vary depending on the assay used. Refer to the package insert of the test for the determination of actual/correct levels of anti-HBs antibodies.

For vaccinated clinicians (who have written documentation of a complete HepB vaccine series) with anti-HBs of 10 mIU/mL or more, testing the source patient for HBsAg is unnecessary. No postexposure prophylaxis for HBV is necessary, regardless of the source patient’s HBsAg status. See Table 1 for quick reference.

For vaccinated clinicians (who have written documentation of a complete HepB vaccine series) without previous anti-HBs testing, two simultaneous tests should be completed without delay:

1. The clinician should be tested for anti-HBs.
2. The source patient (if known) should be tested for HBsAg.

The anti-HBs test should allow for detection of the concentration of anti-HBs that is considered protective (10 mIU/mL or more). See Table 1.

If the clinician has anti-HBs of less than 10 mIU/mL and the source patient is HBsAg-positive or has an unknown HBsAg status, the clinician should receive one dose of HBIG and be revaccinated as soon as possible after the exposure. HepB vaccine may be administered simultaneously with HBIG but must be administered in a different anatomical injection site (e.g., separate limb).

The clinician should then receive the second two doses of HepB vaccine to complete the second series (six doses total when accounting for the original series) according to the vaccination schedule. Anti-HBs testing should be performed 1–2 months after the final vaccine dose so the clinician's vaccine response status can be documented for future exposures.

If the clinician has anti-HBs of less than 10 mIU/mL and the source patient is HBsAg- negative, the clinician should receive an additional single HepB vaccine dose, followed by repeat anti-HBs testing 1–2 months later. Clinicians whose anti-HBs remains less than 10 mIU/mL should undergo revaccination with two more doses (likely six doses total when accounting for the original series). Anti-HBs testing should be performed 1–2 months after the final dose of vaccine.

If the clinician has anti-HBs of 10 mIU/mL or more at the time of the exposure, no postexposure HBV management is necessary, regardless of the source patient's HBsAg status.

For vaccinated clinicians with anti-HBs of less than 10 mIU/mL after two complete HepB vaccine series, the source patient should be tested for HBsAg as soon as possible after the exposure. If the source patient is HBsAg-positive or has unknown HBsAg status, the clinician should receive two doses of HBIG.23 The first dose should be administered as soon as possible after the exposure, and the second dose should be administered 1 month later.

HepB vaccine is not recommended for the exposed clinician who has previously completed two HepB vaccine series. If the source patient is HBsAg-negative, neither HBIG nor HepB vaccine is necessary. See Table 1.

For unvaccinated or incompletely vaccinated clinicians, the source patient should be tested for HBsAg as soon as possible after the exposure. Testing unvaccinated or incompletely vaccinated clinicians for anti-HBs is not necessary and is potentially misleading. This is because anti-HBs of 10 mIU/mL or more can only indicate vaccine-induced protection for those who have completed an approved vaccination series.4 See Table 1.

If the source patient is HBsAg-positive or has an unknown HBsAg status, the clinician should receive one dose of HBIG and one dose of HepB vaccine, administered as soon as possible after the exposure. HepB vaccine may be administered simultaneously with HBIG at a separate anatomical injection site (e.g., separate limb). The clinician should complete the HepB vaccine series according to the vaccination schedule.

To document the clinician's vaccine response status for future exposures, anti-HBs testing should be performed approximately 1–2 months after the final vaccine dose. The anti-HBs test should allow for detection of the concentration of anti-HBs that is considered protective (10 mIU/mL or more). Because anti-HBs testing of clinicians who received HBIG should be performed after anti-HBs from HBIG is no longer detectable (6 months after administration), it might be necessary to defer anti-HBs testing for a period longer than 1–2 months after the last vaccine dose in these situations. See Table 1.

Clinicians with anti-HBs of 10 mIU/mL or more after receipt of the primary vaccine series are considered immune. Immunocompetent people have long-term protection and do not need further periodic testing to assess anti-HBs levels.

Clinicians with anti-HBs of less than 10 mIU/mL after receipt of the primary series should be revaccinated. For these clinicians, anti-HBs testing should be performed 1–2 months after completing the second vaccine series so the clinician's vaccine response status can be documented for future exposures.

If the source patient is HBsAg-negative, the clinician should complete the HepB vaccine series according to the vaccination schedule. So that the clinician's response status can be documented for future exposures, anti-HBs testing should be performed approximately 1–2 months after the final vaccine dose. See Table 1.

Clinicians with anti-HBs of 10 mIU/mL or more after receiving the primary vaccine series are considered immune. People who are immunocompetent have long-term protection and should not need further anti-HBs testing. Clinicians with anti-HBs of less than 10 mIU/mL after receiving the primary series should be revaccinated.

Clinicians who have anti-HBs of less than 10 mIU/mL (or who are unvaccinated or incompletely vaccinated) and sustain an exposure to a source patient who is HBsAg-positive or has an unknown HBsAg status should undergo baseline testing for HBV infection as soon as possible after the exposure, and follow-up testing approximately 6 months later. Testing immediately after exposure should consist of total anti-HBc, and follow-up testing approximately 6 months later should consist of HBsAg and total anti-HBc. See Table 1.

Clinicians exposed to a source patient who is HBsAg-positive or has an unknown HBsAg status do not need to take special precautions to prevent secondary transmission during the follow-up period. However, they should refrain from donating blood, plasma, organs, tissue, or semen.3

The exposed clinician does not need to modify sexual practices or refrain from becoming pregnant.3 If an exposed clinician is breastfeeding, they do not need to stop.35 No modifications to an exposed clinician's patient-care responsibilities are necessary to prevent transmission to patients based solely on exposure to a source patient who is HBsAg-positive or has an unknown HBsAg status.

An increasing number of clinicians have received routine HepB vaccination during childhood. Postvaccination serological testing is not recommended after routine infant or adolescent HepB vaccination. Because vaccine-induced anti-HBs wanes over time, testing clinicians for anti-HBs years after vaccination might not distinguish vaccine non-responders from responders.

Preexposure assessment of current or past anti-HBs results upon hire or matriculation, followed by one or more additional doses of HepB vaccine for clinicians with anti-HBs of less than 10 mIU/mL and retesting anti-HBs, if necessary, helps to ensure that clinicians will be protected if they have an exposure to HBV-containing blood or body fluids. See Box 5; Figure 3 on MMWR for reference.

Clinicians who cannot provide documentation of three doses of HepB vaccine should be considered unvaccinated and should complete the vaccine series. Postvaccination serological testing for anti-HBs is recommended 1–2 months after the third vaccine dose.

Clinicians who are inadvertently tested before receiving three documented doses of HepB vaccine and have anti-HBs of 10 mIU/mL or more should not be considered immune because anti-HBs of 10 mIU/mL or more is a known correlate of protection only when testing follows a documented three-dose series. Health care facilities are encouraged to try to locate vaccine records for clinicians and to enter all vaccine doses in their state immunization information system.