PRRSV-VR2332减毒活疫苗不影响猪瘟疫苗和猪圆环病毒2型灭活疫苗诱导的抗体产生

本研究拟评估仔猪接种猪繁殖与呼吸综合征减毒活疫苗对猪圆环病毒病疫苗、猪瘟疫苗免疫的干扰情况，并分析不同免疫方式对仔猪生长性能的影响，以期为探究PRRSV减毒活疫苗与PCV2、CSF疫苗的联合免疫提供数据参考。本研究先以100头仔猪为研究对象，将其随机分为A、B、C、D 4组。其中A组仔猪免疫PRRSV减毒活疫苗7 d后免疫PCV2疫苗；B组仔猪同期分点注射PRRSV减毒活疫苗和PCV2疫苗；C组仔猪仅免疫PCV2疫苗；D组仔猪仅免疫PRRSV减毒活疫苗。另外再筛选100头仔猪，随机分为E、F、G、H 4组。E组仔猪于免疫PRRSV减毒活疫苗12 d后免疫CSF疫苗；F组仔猪同期分点注射PRRSV减毒活疫苗和CSF疫苗；G组仔猪仅免疫CSF疫苗；H组仔猪仅免疫PRRSV减毒活疫苗。免疫4周后，测定仔猪血清中相关抗体水平。同时，称量免疫前后各组仔猪的体重，计算不同免疫方案仔猪的平均日增重。结果表明：A~D组中， A组和B组仔猪在免疫4周后均产生了较高水平的PRRSV及PCV2抗体，且A组抗体水平略高于B组。C组仔猪仅产生了PCV2抗体，D组仔猪产生了较高水平的PRRSV抗体。E~H 4组中，E组和F组仔猪均产生了较高水平的PRRSV及CSFV抗体。G组仔猪仅产生了高水平的CSFV抗体，H组仔猪仅产生了高水平的PRRSV抗体。A、B、C、D 4组中B组仔猪的平均日增重最高；而E、F、G、H 4组中E组仔猪的平均日增重显著高于其他3组。PRRSV减毒活疫苗与PCV2疫苗或CSF疫苗同期分点免疫、免疫PRRSV减毒活疫苗一段时间后再免疫PCV2或CSF疫苗均能诱导仔猪产生高水平的抗体；在体液免疫方面，PRRSV减毒活疫苗免疫与否均未对另外二种疫苗表现出明显的干扰作用。在仔猪28日龄时同期分点免疫PRRSV减毒活疫苗与PCV2疫苗，12 d后再免疫CSF疫苗的免疫方案不仅能诱导仔猪产生高水平抗体，还可以使仔猪具备较高的平均日增重。

PRRSV-VR2332 Modified Live Attenuated Vaccine does not Affect the Antibody Production Induced by Classical Swine Fever Vaccine and Inactivated Porcine Circovirus Type 2 Vaccine

This study intends to evaluate the interference of porcine reproductive and respiratory syndrome virus modified live attenuated virus vaccine (PRRSV MLV-vaccine) on the immune effect of PCV2 and CSFV vaccine, and analyze the effects of different immunization methods on the growth of piglets. It is expected to provide data for exploring the combined immunization of PRRSV MLV-vaccine and PCV2 and CSF vaccine. In this study, 100 piglets were selected and randomly divided into A, B, C, and D 4 groups. Group A was immunized with PCV2 vaccine 7 days after the PRRSV MLV-vaccine; group B was simultaneously immunized with PRRSV MLV-vaccine and PCV2 vaccine; group C was immunized with PCV2 vaccine and group D was immunized with PRRSV MLV-vaccine. Then another 100 piglets were selected and randomly divided into E, F, G, and H 4 groups. Group E was injected with CSFV vaccine 12 days after the PRRSV MLV-vaccine; group F was simultaneously immunized with PRRSV MLV-vaccine and CSFV vaccine; group G was immunized with CSFV vaccine and group H was immunized with PRRSV MLV-vaccine. After 4 weeks of immunization, the level of antibodies in the serum of the piglets was measured. The weight of piglets in each group was measured before and after the experiment, and the average daily gain (ADG) of piglets in different groups was calculated. In groups A-D, group A and B produced high level of antibody responses against PRRSV and PCV2. Group C only produced high level of antibody responses against PCV2, while group D produced high level of antibody responses against PRRS. Among the 4 groups of E-H, the group E and F produced high level of antibody responses against PRRSV and CSFV. Group G only produced high level of antibody responses against CSFV, while group H only produced high level of antibody responses against PRRSV. The ADG of group B among the A, B, C, and D was the highest; while the ADG of group F among the of E, F, G, and H was significantly higher than that of the other three groups. Both simultaneous immunization with PRRSV MLV-vaccine and PCV2 or CSFV vaccine, and subsequent immunization with PCV2 or CSFV vaccine after vaccination with PRRSV MLV-vaccine, could induce high levels of antibody production; in terms of humoral immunity, neither immunization nor non-immunization of the PRRSV MLV-vaccine showed significant immune interference to the other two vaccines. Therefore, “simultaneous immunization with PRRSV MLV-vaccine and PCV2 vaccine at 28 days of age, followed by immunization with CSFV vaccine 12 days later” not only induced high levels of antibody responses, but also resulted in a higher ADG.