Hepatitis B Titer of 11.2 mIU/mL: Booster Not Recommended
A booster dose is not recommended for an immunocompetent individual with a hepatitis B surface antibody (anti-HBs) titer of 11.2 mIU/mL who previously completed a primary vaccination series and achieved protective levels. 1
Understanding the Titer Result
Your titer of 11.2 mIU/mL is above the protective threshold of 10 mIU/mL, indicating you have adequate immunity against hepatitis B. 2
The CDC Advisory Committee on Immunization Practices (ACIP) recognizes antibody titers ≥10 mIU/mL as conferring protection against hepatitis B infection. 3
Why No Booster Is Needed
For healthy individuals who completed the primary hepatitis B vaccination series and showed an adequate response, immunity is long-lasting and booster doses are generally not recommended. 1
The presence of immune memory, rather than circulating antibody levels, is the key determinant of long-term protection against clinical disease. 1
Immune memory can persist even when antibody levels decline below 10 mIU/mL in immunocompetent individuals, providing protection through rapid anamnestic response upon exposure. 1, 4
The American Gastroenterological Association concluded there is insufficient evidence to support using anti-HBs titers to guide prophylaxis decisions, as the effect of titer level on protection has not been well established. 2
Important Exceptions Requiring Different Management
You WOULD need annual monitoring and boosters if you are:
On hemodialysis: Annual anti-HBs testing is required, with booster doses administered when levels decline below 10 mIU/mL. 1, 3
Immunocompromised: Annual anti-HBs testing and booster doses should be considered if you have ongoing risk for exposure. 1, 4
Healthcare personnel with occupational exposure risk: If you never achieved anti-HBs ≥10 mIU/mL after primary vaccination, you would need additional doses. 1
Common Pitfalls to Avoid
Do not confuse the initial post-vaccination testing threshold (which should ideally be >100 mIU/mL to ensure durability) with the ongoing protection threshold of ≥10 mIU/mL. 5, 6
Do not administer unnecessary booster doses to healthy individuals who responded to the primary series, as this is not supported by current evidence. 1
Do not assume that declining antibody levels mean loss of protection in immunocompetent individuals—cellular immune memory provides ongoing protection. 1, 4
For immunocompromised persons and liver transplant recipients, regular serological testing and revaccination to maintain anti-HBs ≥10 mIU/mL are recommended. 4