Immune Efficacy Of Inactivated Vaccine Of Porcine Pseudorabies Virus Triple Gene Deletion Strain

Since 2011,a new round of pseudorabies epidemics has erupted in China.The new round of pseudorabies epidemic has mixed infections and complex disease types.Research have shown that the existing vaccines have poor immune protection against some wild-type infections.Therefore,it is very important to develop a vaccine that could effectively prevent and control the new pseudorabies epidemic.Based on the successful construction of attenuated PRV strains(GD0304 TK-/g E-/g I-strain)in the laboratory,development of a new inactivated vaccine against pseudorabies virus(GD0304 TK-/g E-/g I-strain)with this attenuated strain.In order to understand the immunological efficacy of the porcine pseudorabies inactivated vaccine(GD0304 TK~-/g E~-/g I~-strain)and provide reference data for further clinical application of the vaccine,the experiment firstly used the mouse immune challenge protection test to explore the immune efficacy of the gene-deficient strain.The mice were immunized with different groups of mice using the pseudorabies inactivated vaccine and the control vaccine(Bartha K61).Intensive immunization once after 3 weeks of the first exemption,blood sampling before the challenge for serum neutralization experiments.The results showed that the neutralizing titers of PRV GD0304 in the pig pseudorabies inactivated vaccine group,Bartha K61 vaccine group and experimental control group were 1:25.1,1:5.62 and 0,and the protection rate of attack were 100%,50%and 0%;After the necropsy,no significant pathological changes were observed in the experimental pseudorabies inactivated vaccine group.The Bartha K61 vaccine group and the control group had obvious clinical symptoms and pathological changes.Based on the above results,it can be preliminarily concluded that the immune efficacy of the pseudorabies inactivated vaccine(GD0304 TK~-/g E~-/g I~-strain)is stronger than that of the Bartha K61 attenuated vaccine,and it can effectively protect the immunized mice from the pseudorabies variant strain.Based on the mouse challenge protection test,using target animals to studied the immunogenicity of the pseudorabies inactivated vaccine(GD0304 TK~-/g E~-/g I~-strain).Immunization of piglets with pseudorabies inactivated vaccine and commercial inactivated vaccine.The strengthen immunization after 3 weeks of the first exemption.After the first exemption,collected blood once a week to detect g E and g B antibody levels.The challenge after 2 weeks of the strengthen immunization.After the challenge,no inactivated seedlings showed obvious clinical symptoms,and no obvious lesions were observed after the necropsy.After the challenge,inactivated vaccine group not showed obvious clinical symptoms,and no obvious lesions were observed after the necropsy.The commercial inactivated seedling group,1/5 piglets have clinical symptoms;The experimental control group,all piglets were infected after the challenge,and 3/5 piglets died.The results of nasal detoxification showed that the output of piglets in the commercial inactivated vaccine group was higher than that in the pseudorabies inactivated vaccine group,and was lower than that in the control group.The results of serum neutralization experiments showed that the serum neutralizing titers of PRV GD0304 in pigs of pseudorabies inactivated vaccine and commercial inactivated vaccine group were 1:15.8 and1:11.2.The serum of piglets in control group did not neutralize PRV GD0304.Therefore,compared with the commercial inactivated vaccine,the pig pseudorabies inactivated vaccine(GD0304 TK~-/g E~-/g I~-strain)could more effectively protect piglets from the attack of PRV GD0304 strain.In order to select high-quality adjuvants to improve the immune effect of the pig pseudorabies inactivated vaccine(GD0304 TK~-/g E~-/g I~-strain),The three different adjuvants,such as ISA 201,IMS 1313 and GEL 01,were using to prepared vaccines and immunize piglets.The strengthen immunization after 3 weeks of the first exemption.After the first exemption,collected blood once a week to detect g E and g B antibody levels.After the challenge,no obvious pseudorabies clinical symptoms and lesions were observed in the piglets of the inactivated vaccine(ISA 201)group.The inactivated vaccine(IMS 1313)group 1/5 piglets showed mild clinical symptoms;The inactivated vaccine(GEL 01)group 2/5 piglets showed mild mild clinical symptoms,including 1 case of tonsil enlargement,suppuration,lung bleeding.The experimental control group,all piglets were infected after the challenge,and 3/5 piglets died.The results of intranasal detoxification showed that the piglets in the control group were the highest in the control group and the lowest in the inactivated vaccine(IMS 1313)group.The results of serum neutralization experiments showed that the neutralizing titers of PRV GD0304 in serum of inactivated vaccine(ISA 201),inactivated vaccine(IMS 1313)and inactivated vaccine(GEL 01)groups were 1:15.8,1:19.9,1:11.2.The above results indicated that the inactivated porcine pseudorabies vaccine(GD0304 TK~-/g E~-/g I~-strain)prepared by three different adjuvants could provide effective protection to weaned piglets.ISA201 and IMS 1313 adjuvants are more suitable for the development of inactivated porcine pseudorabies vaccine(GD0304 TK~-/g E~-/g I~-strain).