Background Combined hepatitis A and B vaccine administered on an accelerated schedule provides a rapid immune response against both hepatitis A and B viruses, which might be especially relevant for individuals who need protection quickly.
Methods A prospective, open-label, randomized study to compare the immunogenicity and reactogenicity of the combined hepatitis A and B vaccine Twinrix (GlaxoSmithKline Biologicals, Rixensart, Belgium) (≥720 EL.U/mL inactivated hepatitis A antigen and 20 μg/mL recombinant hepatitis B surface antigen [HBsAg]) administered at 0, 7, 21 to 30 days, and 12 months compared with concurrent administration of Havrix [GlaxoSmithKline Biologicals, Rixensart, Belgium (≥1440 EL.U/mL inactivated hepatitis A antigen)] at 0 and 12 months, and Engerix-B [GlaxoSmithKline Biologicals, Rixensart, Belgium (20 μg/mL recombinant HBsAg)] at 0, 1, 2, and 12 months in seronegative healthy adults.
Results At month 13, the anti-hepatitis B seroprotection rates (>10 mIU/mL) for the combined vaccine compared to the monovalent hepatitis B vaccine were 96.4% (95% CI: 92.7–98.5) and 93.4% (95% CI: 89.0–96.4), respectively. The anti-hepatitis A seroconversion rates were 100% in both groups (95% CI: 98.1–100). At day 37, the anti-hepatitis A seroconversion rates were similar in both groups (98.5% for combined vaccine, 98.6% for the monovalent vaccine group), but the combined vaccine resulted in a statistically significantly ( p < 0.001) better anti-hepatitis B seroprotection compared to monovalent hepatitis B vaccine, 63.2% versus 43.5%, respectively. The reactogenicity profile was similar in both study groups.
Conclusions The combined hepatitis A and B vaccine administered on an accelerated schedule was at least as immunogenic and as well tolerated as the corresponding monovalent vaccines.