<p>(<b>A</b>) Schematic diagram of recombinant vaccinia virus RVJSS1, which contains two expression cassettes in a back-to-back orientation, flanked by vaccinia virus TK region sequences. Virus RVJSS1 was a Tiantan strain vaccinia virus with a <i>lacZ</i> gene led by a p11 promoter inserted into the TK region; the expression cassette on the right consists of the SS1 fusion protein led by the 7.5 K promoter. (<b>B</b>) Immunofluorescence assay to confirm SS1 fusion protein expression. CEF cells were infected by the purified RVJSS1 virus and fixed, permeabilised, stained with rabbit anti-PreS1 antibody and fluorescein isothiocyanate (FITC) conjugated to a secondary antibody, and then visualised using fluorescence microscopy. (<b>C</b>) Western blot analyses to detect expression of SS1 fusion proteins in CEFs infected with RVJSS1 using specific antibodies. The expression bands of the SS1 proteins are indicated by arrowheads. (<b>D</b>) Negative staining of purified HBVSS1 particles vaccine using electron microscopy.</p
