Twinrix Alternative Schedule Study

A Study Comparing the Effectiveness of Two Different Vaccination Schedules of the Combined Hepatitis A and B Vaccine(Twinrix Adult1440/20)

To compare the efficiency of protection against hepatitis-B virus by administration of the combined vaccine against hepatitis A and B using the schedule 0-1-12 months against the schedule 0-1-6 months.

1. To compare the seroconversion (>= 1 IU/l) and seroprotection (>= 10 IU/l) rate at month 6,7,12 and 13.
2. To compare the distribution of anti-HBs at these different moments.

Inclusion Criteria:

• 18 years or older;
• a good physical condition as confirmed by history and physical examination at entry of the study;
• for female participants who could become pregnant in the course of the study a contraceptive programme is foreseen;
• all participants have provided written informed consent.

Exclusion Criteria:

• Employees occupationally exposed to hepatitis B virus
• Other exclusion criteria listed for the vaccine (licensed vaccine):
• Each acute disease at the inclusion in the study;
• A history of hypersensibility to one of the components of the vaccine;
• Simultaneous participation in another clinical trial