Long-term antibody persistence against hepatitis B in adolescents 14-15-years of age vaccinated with 4 doses of hexavalent DTPa-HBV-IPV/Hib vaccine in infancy

Abstract

We evaluated antibody persistence against hepatitis B virus (HBV) in adolescents previously vaccinated with a hexavalent diphtheria-tetanus-acellular pertussis-HBV-inactivated poliovirus-Haemophilus influenzae type b conjugate vaccine (DTPa-HBV-IPV/Hib), as part of the national newborn immunization program in Germany. We also assessed the anamnestic response to a challenge dose of a monovalent HBV vaccine. In this phase 4, open-label, non-randomized study (NCT02798952), 302 adolescents aged 14-15 years, primed in their first 2 years of life with 4 DTPa-HBV-IPV/Hib doses, received one challenge dose of monovalent HBV vaccine. Blood samples were taken before and one month post-vaccination and used to determine antibody levels against hepatitis B surface antigen (HBs). Reactogenicity and safety were also assessed post-challenge dose. Pre-challenge dose, 53.7% of 268 participants included in the according-to-protocol cohort for immunogenicity had anti-HBs antibody concentrations ≥10 mIU/mL (seroprotection cut-off) and 16.8% had anti-HBs antibody concentrations ≥100 mIU/mL. One month post-challenge dose, 93.3% of adolescents had anti-HBs antibody concentrations ≥10 mIU/mL and 87.3% had antibody concentrations ≥100 mIU/mL. An anamnestic response was mounted in 92.5% of adolescents. Injection site pain (in 33.6% of participants) and fatigue (30.2%) were the most frequently reported solicited local and general symptoms, respectively. Six of the 55 unsolicited adverse events reported were considered vaccination-related. Two vaccination-unrelated serious adverse events were reported during the study. Long-term antibody persistence against hepatitis B was observed in 14-15 years old adolescents previously primed in infancy with DTPa-HBV-IPV/Hib. A challenge dose of monovalent HBV vaccine induced strong anamnestic response, with no safety concerns.

Keywords: DTPa-HBV-IPV/Hib; adolescents; anamnestic response; challenge dose; hepatitis B; immune memory; long-term persistence; seroprotection.

Figures

Figure 1.

Focus on Patient Section.

Figure 2.

Participant flow chart. ATP, according-to-protocol; N, number of participants; HBc, hepatitis B core antigen.Note: *One participant also had positive anti-HBc status 1 month post-challenge dose.

Figure 3.

Percentage of adolescents with solicited local and general symptoms (total vaccinated cohort). GI, gastrointestinal; Fever, temperature ≥ 37.5°C; N, number of participants with documented dose.Note: Grade 3 events were defined as preventing normal daily activities (for pain, fatigue, GI symptoms and headache), surface >50 mm (for redness, swelling) and temperature >39°C (fever). Error bars represent 95% confidence intervals.