AMBIRIX Suspension for injection Ref.[49680] Active ingredients: Hepatitis A, inactivated vaccine Hepatitis B, purified antigen

Pharmaco-therapeutic group: Vaccines, Hepatitis vaccines
ATC code: J07BC20

Mechanism of action

Ambirix confers immunity against HAV and HBV infection by inducing specific anti-HAV and anti-HBs antibodies.

Clinical studies

Immune responses post-primary vaccination

In clinical studies involving subjects from 1 year up to and including 15 years old, seropositivity rates for anti-HAV antibodies were 99.1% one month after the first dose and 100% after the second dose given at month 6 (i.e month 7). Seropositivity rates for anti-HBs antibodies were 74.2% one month after the first dose and 100% after the second dose given at month 6 (i.e. month 7). The anti-HBs seroprotection rates (titers ≥10 mlU/ml) at these time points were 37.4% and 98.2% respectively.

In a comparative clinical trial conducted among subjects aged from 12 years up to and including 15 years of age, 142 received two doses of Ambirix and 147 received the standard three-dose (0, 1, 6 months) of the combined HAB vaccine. The latter contained 360 ELISA Units of formalin inactivated hepatitis A virus and 10 micrograms of recombinant hepatitis B surface antigen. For the 289 subjects evaluable for immunogenicity, seroprotection rates (SP in the table below) against hepatitis B were significantly higher at months 2 and 6 with the three-dose vaccine than with Ambirix. The immune response elicited by Ambirix at month 7 (i.e. after completion of the vaccination course) was non-inferior to that to the three-dose vaccine.

^* containing 360 ELISA Units of formalin inactivated hepatitis A virus and 10 micrograms of recombinant hepatitis B surface antigen

Immune responses obtained one month after the full vaccination course (i.e at month 7) in a comparative clinical trial in children aged 1-11 years are presented in the following table. Also shown are the results reported in the comparative study performed in 12-15 year-olds. In both studies, subjects received either a two-dose schedule of Ambirix or a three-dose regimen of the combined HAB vaccine (360/10) containing 360 ELISA Units of formalin inactivated hepatitis A virus and 10 micrograms of recombinant hepatitis B surface antigen.

^* containing 360 ELISA Units of formalin inactivated hepatitis A virus and 10 micrograms of recombinant hepatitis B surface antigen

Immune response post-primary vaccination using 0-12 month schedule

In a clinical study, 102 subjects aged from 12 years up to and including 15 years received the second dose of Ambirix at month 12. Seropositivity rates for anti-HAV were 99.0% and seropositivity rates for anti-HBs were 99.0% at month 13 with seroprotection rates of 97.0%.

Persistence of immune responses

The persistence of immune responses was evaluated in children up to 15 years after primary vaccination with Ambirix and is presented in the Table below.

After 15 years in subjects aged 12-15 years at primary vaccination the anti-HAV and anti-HBs antibody concentrations were comparable between groups that had received Ambirix or a 3-dose regimen of the combined HAB vaccine (360/10). In the Ambirix group, a challenge dose of a HBV vaccine was given to a limited number of subjects (n=8) whose anti-HBs antibody concentrations decreased to <10 mIU/ml and all mounted an anamnestic response.

Concomitant vaccinations

When the first dose of Ambirix was administered concomitantly with a booster dose of a combined diphtheria, tetanus, acellular pertussis, inactivated poliomyelitis and Haemophilus influenzae type b vaccine (DTPa-IPV+Hib) or with the first dose of a combined Measles-Mumps-Rubella vaccine in the second year of life, immune responses to all antigens were satisfactory.