Preparation method of phage display-expressing circovirus antigen vaccine

The invention provides a preparation method of a phage display-expressing circovirus antigen vaccine. The preparation method comprises the following steps: extracting porcine circovirus II type (PCV2) RNA, carrying out inverse transcription, carrying out a polymerase chain reaction (PCR) for amplification so as to obtain porcine II type circovirus ORF2 gene's open reading frame fragments, directionally inserting the fragments into a T4 phage; obtaining a T4 phage with the ORF2 gene by an immunoscreening method; purifying and infecting X-Blue ST1(CCTCC M 2014397) host cell again; carrying out fermental cultivation to obtain the X-Blue ST1 host cell, and carrying out inducible expression and inactivation and taking a culture as an antigen; carrying out ELISA calibration of antigen valence, and carrying out double dilution on the antigen with normal saline to the final concentration of 107U/ml; and a vaccine adjuvant is added according to the ratio of 1:2.5, so as to obtain the vaccine. According to the invention, the phage is utilized to express the porcine circovirus II type antigen and the vaccine is prepared. Thus, the virulence enhancement risk of an attenuated vaccine is avoided. In addition, fermental cultivation is beneficial to large-scale industrial production. Cost of the vaccine provided by the invention is far lower than that of a vaccine produced by a cell culture method.