195-LB: Lower Nonresponse Rates to 3-Antigen HBV Vaccine among Adults with Diabetes, Age 45 and Over, or Obesity Compared with a Single-Antigen HBV Vaccine: PROTECT Study

Diabetes mellitus (DM), older age (≥45 years) and obesity (BMI >30 kg/m2) are associated with lower response to immunizations and worse outcomes of chronic hepatitis B infection. Therefore, there is a need to enhance immunogenicity of HBV vaccine for adults, especially those with DM, older age, and obesity. PROTECT study compared the immunogenicity and safety of 3-doses of 3-antigen / 3A-HBV (Sci-B-Vac) and 1-antigen / 1A-HBV (Engerix-B) HBV vaccines administered at months 0, 1 and 6. The study enrolled 1607 adults age ≥18 years in the US (42.3%), Europe (41.6%) and Canada (16.1%). Immunogenicity, measured as rate of non-response (% not achieving anti-HBs levels ≥10 mIU/mL), anti-HBs geometric mean concentration (GMC), and safety were evaluated in all adults and key subgroups of interest. Of 1607 study participants, 7.5% (3A-HBV arm) and 8.0% (1A-HBV arm) had a stable and well controlled DM (HbA1c 30 kg/m2. Overall non-response rates were 23.5% (1A-HBV) and 8.6% (3A-HBV). For diabetics, non-response rates were 41.7% (1A-HBV) and 16.7% (3A-HBV), for those age ≥45 years, 34.3% (1A-HBV) and 16.4% (3A-HBV) and for BMI >30 kg/m2, 31.9% (1A-HBV) and 10.8% (3A-HBV). Mean GMC of anti-HBs was higher for 3A-HBV compared to 1A-HBV (1424.5 vs. 235.4 mIU/mL) and consistently higher across key subgroups, including those with DM, age ≥45 years and BMI >30 kg/m2. Safety of 3A-HBV was comparable to 1A-HBV except for higher rates of injection site pain, tenderness and myalgia of mild to moderate severity and mean duration of 1-2 days. Completion rate of all 3 vaccine doses was high at 96.8% (1A-HBV) and 95.2% (3A-HBV). Immunization with 3A-HBV achieved lower rates of non-response compared to 1A-HBV in all adults, including those with diabetes, older age, and obesity. Disclosure F. Diaz-mitoma: Consultant; Self; VBI Vaccines. Protect study group: n/a. T. Vesikari: Research Support; Self; VBI Vaccines. J. M. Langley: Research Support; Self; GlaxoSmithKline plc., Medicago, VIDO, Entos, Merck & Co., Inc., Pfizer Inc., Sanofi. A. Hossain: None. N. Machluf: Employee; Self; VBI Vaccines. J. Spaans: Employee; Self; VBI Vaccines Inc. B. Yassin-rajkumar: None. D. E. Anderson: Employee; Self; VBI Vaccines, Inc., Stock/Shareholder; Self; VBI Vaccines, Inc. V. Popovic: Employee; Self; VBI Vaccines.