猪圆环病毒2型重组杆状病毒亚单位疫苗制备及其与商品化疫苗免疫效果比较OA

Porcine circovirus type 2(PCV2)infection is one of the major diseases harming China's swine industry,with vaccination as the primary control strategy.To compare the immunization effects of different types of PCV2 vaccines,this study used the PCV2 recombinant baculovirus OKM strain to infect insect cells,purified the recombinant protein,and prepared a subunit vaccine;three commercial vaccines,a whole-virus inactivated PCV2 vaccine,an E.coli-expressed PCV2 subunit vaccine,and an imported baculovirus-expressed PCV2 subunit vaccine,were also selected.Each vaccine was administered to 21-28-day-old piglets confirmed negative for PCV2 nucleic acid and ELISA antibodies to evaluate immunoprotective efficacy.The results showed that the recombinant Cap protein prepared in this study formed typical virus-like particles(VLPs).The prepared subunit vaccine and all three commercial vaccines induced PCV2 ELISA antibodies in piglets.At 35 days post-immunization,piglets were challenged with a virulent PCV2 strain and observed for 25 consecutive days.No abnormal clinical signs or pathological changes were observed in any immunized group after challenge.Although average daily gain(ADG)did not differ significantly among the four immunized groups,all were significantly higher than the non-immunized challenge control group.Protective efficiency in all immunized groups was not less than 80％.Viremia showed no significant differences among immunized groups and was significantly lower than that of the non-immunized challenge control group.These findings indicate that the immunization effect of the recombinant baculovirus-derived PCV2 subunit vaccine(OKM strain)is similar to that of commercial vaccines.