The invention relates to a multi-HBV immunogen viral vector vaccine comprising: a viral vector comprising an immunogen expression cassette, wherein the expression of a protein encoded by the expression cassette is arranged to be driven by a promoter, wherein the immunogen expression cassette encodes: a) HBV Core; b) a modified HBV polymerase (Pmut), wherein the modification is a mutation to wild-type HBV polymerase to substantially remove polymerase function; c) HBV surface antigen (HbsAg); and d) an intergenic sequence that is arranged to cause expression of at least the HBV surface antigen (HbsAg) as a separate protein from the HBV core and the modified HBV polymerase (Pmut), wherein the intergenic sequence is downstream (3') of the sequences encoding the HBV core and the modified HBV polymerase (Pmut) and upstream (5') of the sequence encoding the HBV surface antigen (HbsAg); and related compositions, vaccination methods and methods of treatment or prophylaxis of HBV infection.