Diabetes, obesity, and older age are considered main risk factors that yield non-responses to different HBV vaccines.
There are various risk factors that yield lower responses to immunizations and negative outcomes for chronic hepatitis B virus (HBV) infections, including diabetes mellitus, older age, and obesity, leading to a need to enhance immunogenicity of HBV vaccines for adults with these risk factors.
In data presented during the American Diabetes Association’s (ADA) 81th Scientific Sessions, a team, led by Francisco Diaz-Mitoma, MD, PhD, VBI Vaccines, 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.
In the study, the researchers examined 1607 adult patients from the US (42.3%), Europe (41.6%), and Canada (16.1%).
The investigators evaluated Immunogenicity, measured as rate of non-response (% not achieving anti-HBs levels ≥10 mIU/mL), anti-HBs geometric mean concentration (GMC), and safety in all adults, as well as key subgroups.
The overall non-response rates were 23.5% for 1A-HBV and 8.6% for 3A-HBV.
However, the non-response rates rose for patients with the identified risk factors of diabetes, older age, and obesity
For diabetics, non-response rates were 41.7% for 1A-HBV and 16.7% for 3A-HBV and 34.3% for 1A-HBV and 16.4% for 3A-HBV for individuals at least 45 years old. For patients with a body mass index (BMI) greater than 30 kg/m2, the non-response rates were 31.9% for 1A-HBV and 10.8% for 3A-HBV.
The mean GMC of anti-HBs was higher for 3A-HBV compared to 1A-HBV (1424.5 vs. 235.4 mIU/mL).
The mean GMC was also consistently higher among all key subgroups.
In addition, 7.5% of patients in the 3A-HBV arm and 8.0% of participants in the 1A-HBV cohort had a stable and well controlled DM (HbA1c <8.5%), of which 81.4% were at least 45 years old and 36.7% had BMI greater than 30 kg/m2.
The safety of the 2 vaccines were similar, except for higher rates of injection site pain, tenderness and myalgia of mild to moderate severity and mean duration of 1-2 days following the injection of 3A-
The completion rate was also similar in both groups of patients in the cohort. For 1A-HBV, the completion rate of all 3 doses was 96.8%, compared to 95.2% for all 3 doses of 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,” the authors wrote.
Earlier this year, researchers found patients with chronic hepatitis C virus (HCV) infection often have poor responses to hepatitis B virus (HBV) vaccination even if they have been treated for HCV and achieved sustained viral response (SVR).
The data offer new insights into the limitations of the HBV vaccine, and could help identify which patients are most likely to benefit from vaccination, and which patients might not.
Among the vaccinated, 57.1% responded to the vaccine, but only 5.1% achieved a seroprotective level of HBsAb titer. Among those with HBcAb, the response rate was just 5.6%, compared to 64.5% in patients without. A multivariate analysis suggested that advanced age, and presence of isolated HBcAb were linked with poor responses.
The study, “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,” was published online by ADA 2021.