From the Guidelines
A positive Hepatitis B surface antibody (HBsAb) with a negative Hepatitis B core antibody (HBcAb) indicates successful vaccination against Hepatitis B virus without prior natural infection. This pattern shows that the individual has developed immunity to Hepatitis B through vaccination rather than from recovering from an actual infection. The surface antibody (HBsAb) is the protective antibody that prevents future infection, and levels above 10 mIU/mL are generally considered protective 1. Since the core antibody (HBcAb) is negative, this confirms the person has never been infected with the actual virus, as core antibodies only develop in response to natural infection.
Key Points
- This serologic pattern represents the ideal outcome of Hepatitis B vaccination programs, providing protection without the person ever having experienced the disease 1.
- No further vaccination is needed unless the person becomes immunocompromised or HBsAb levels fall below protective levels in high-risk individuals 1.
- The presence of anti-HBs typically indicates immunity from HBV infection, and infection or immunization with one serotype of HBV confers immunity to all serotypes 1.
- It's essential to note that while this pattern is indicative of successful vaccination, antibody levels may decline over time, and in some cases, individuals may become susceptible to infection again if they become immunocompromised 1.
Clinical Implications
- Individuals with this serologic pattern are considered immune to Hepatitis B and are not at risk of transmitting the virus to others 1.
- However, it's crucial to monitor HBsAb levels in high-risk individuals, such as those with compromised immune systems, to ensure they remain protected against HBV infection 1.
- In cases where HBsAb levels fall below protective levels, revaccination or other preventive measures may be necessary to maintain immunity 1.
From the Research
Interpretation of Hepatitis B Surface Antibody and Hepatitis B Core Antibody Results
- A positive Hepatitis B surface antibody (HBsAb) result indicates that the individual has immunity to Hepatitis B, either through vaccination or past infection 2.
- A negative Hepatitis B core antibody (HBcAb) result suggests that the individual has not been infected with Hepatitis B in the past, or that the infection was cleared without the development of core antibodies 3, 2.
Implications of HBsAb Positive and HBcAb Negative Results
- The presence of HBsAb without HBcAb indicates that the individual is immune to Hepatitis B, but has not had a past infection that resulted in the development of core antibodies 4, 5.
- This combination of results may be seen in individuals who have been vaccinated against Hepatitis B, as the vaccine only induces the production of surface antibodies, not core antibodies 2, 6.
- The presence of HBsAb has been shown to protect against de novo Hepatitis B infection in individuals with HBcAb-positive liver grafts, and may also reduce the risk of Hepatitis B reactivation in individuals undergoing direct-acting antiviral therapy for Hepatitis C 4, 5.
Clinical Significance
- The interpretation of HBsAb and HBcAb results is important for determining an individual's immunity to Hepatitis B and guiding clinical management decisions 3, 4, 5, 2, 6.
- Further testing, such as measurement of HBsAb titers, may be necessary to confirm immunity and determine the need for additional vaccination or prophylactic measures 4, 5.