Engerix B is indicated for active immunisation against hepatitis B virus infection (HBV) caused by all known subtypes in non immune subjects . The 20 µg dose vaccine in 1.0 ml suspension is intended for use in subjects 16 years of age and above. The 10 µg dose vaccine in 0.5 ml suspension is intended for use in subjects up to and including 15 years of age, including neonates. The categories within the population to be immunised are determined on the basis of official recommendations.It can be expected that hepatitis D will also be prevented by immunisation with Engerix B as hepatitis D (caused by the delta agent) does not occur in the absence of hepatitis B infection.