Trends in Prevalence of Protective Levels of Hepatitis B Surface Antibody Among Adults Aged 18–49 Years With Risk Factors for Hepatitis B Virus Infection—United States, 2003–2014

Abstract Background Hepatitis B virus (HBV) infection can be prevented through vaccination. However, previous data show that only about 24%–45% of US adults at high risk of HBV infection are protected. Our aims were to assess prevalence and trends in protective levels of hepatitis B surface antibody (anti-HBs) from 2003 to 2014 and explore factors associated with protection among adults at high risk. Methods Data were taken from the 2003–2014 National Health and Nutrition Examination surveys. Our sample included adults aged 18-49 years who were tested for HBV and reported at least 1 of the following infection risks: history of sexually transmitted disease, sex with men (for men), infection with human immunodeficiency virus, and injection drug use. We calculated the prevalence of anti-HBs (≥10 mIU/mL), indicative of immunity from vaccination, among respondents for three 4-year time intervals (2003–2006, 2007–2010, and 2011–2014) and applied the Cochran-Mantel-Haenszel test to assess trends. Using multivariable logistic regression, we examined factors associated with positive anti-HBs serology. Results The prevalence of positive anti-HBs serology was 23.4%. Prevalence increased from 2003–2006 (16.3%) to 2007–2010 (27.3%), but no change occurred from 2007–2010 (27.3%) to 2011–2014 (28.1%). Among factors predicting positive anti-HBs serology were young age and higher education. Conclusions By 2014, less than one-third of adults aged 18-49 years at risk of infection exhibited protective antibodies ≥10 mIU/mL. Because these adults account for a majority of unprotected adults, targeted intervention strategies are essential to achieve the hepatitis B elimination goal.