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Porcine reproductive and respiratory syndrome (Porcine Reproductive and Respiratory Syndrome, PRRS), 1987 in the United States was first reported in 1991 in the Netherlands, first isolated the pathogen. PRRSV national popular pig production in many parts of the world, causing huge economic losses. The clinical symptoms of PRRS fattening pigs showed fever, loss of appetite, and difficulty in breathing, wheezing and other respiratory symptoms, the sow mummified low earners increased barriers to abortion and other reproductive system. PRRS has presence in our country with the popular wide distribution and caused huge losses. How to combat PRRS, and reduce the economic losses caused by the livestock and poultry industry is an important issue we face. At home and abroad on the molecular biology of PRRSV, PRRS vaccine and adjuvant extensive research, has brought great difficulties due to a wide range of antigenic variation between virus isolates immune to this disease and prevention . In view of PRRSV caused economic losses and its potential hazards, and the urgent need for effective prevention and control means to control the disease epidemic in our country, and PRRSV immune suppression to the elucidation of the pathogenic mechanism for the prevention and treatment to provide a strong theoretical basis, it is around this problem research and discussion is extremely important. 13 46-day-old healthy piglets, swine fever ELISA diagnostic kit for detection, PRRS antibodies and swine fever antibody by the United States DEXX PRRS EI ISA diagnostic kit and Shenzhen Lvshiyuan, Biotechnology Co., Ltd. was negative. Five of the group A, group B 5 and C group were randomly divided into 3 groups were kept isolated. , A 48-day-old inoculated intranasally with PRRSV LC strains (TCID50 l0-5.25 / 0.1 mL) of 3 mL / head. Group B and Group C intranasal inoculation inoculation end of the normal cell cultures 3 mL / head; 50 days of age, the group A and group B immune swine fever vaccine 4 the C group intramuscular injection 4mL saline. Each group daily measurement of body temperature, observed and recorded clinical symptoms. Immune 1,7,14,21,28 and 35 days of age, after vena cava blood collection, blood collection site shearing disinfection per pig blood was collected in duplicate, each 2 (3 mL) and one diagonal in the refrigerator at 4 ℃ allowed to stand overnight, and serum was separated; another heparin isolated lymphocytes, detection of T lymphocyte transformation rate. The results show that: the immune 7 days, B group of classical swine fever vaccine antibody titers highly significant increase (P lt; 0.01); Group A hog cholera vaccine increased antibody titers were not statistically significant (P gt; 0.05). Since 14 days after immunization, the antibody titers of classical swine fever vaccine B group pigs was significantly higher than that in group A, and PRRSV significant inhibition of pigs humoral immune response. The conversion rate of 1 day, A, B, C three groups of pigs in PBMC after immunization no significant difference (P gt; 0.05); immune after 7,21,28 and 35 days, the B group of pigs in PBMC conversion rate higher than that in group A pigs, PRRSV significantly inhibited the cellular immune function of pigs. Three 60-day-old healthy piglets were randomly divided into A, B groups, group A 2, B group one; A group inoculated intranasally with PRRSV LC strains (TCID50 l0-5.25 / 0.1 mL) 3 mL / head ; observation of clinical symptoms, the drug 25 days after the attack, killed to take the lymph nodes, spleen, lungs and liver, neutral formalin fixed paraffin sections, observe the histopathological changes. The results showed that: A group of pigs of the experimental group, the liver can be seen the expansion of the central vein, full of red blood cells, liver sinusoidal expansion, we can see a large number of red blood cells, liver cell necrosis, disintegration, visible cell debris; lymphoid nodules enlargement, increased lymphatic sinuses filled with oozing liquid; spleen lymphoid nodules shrink, be seen scattered in the cell debris and focal hemorrhage; lungs visible widening of the alveolar wall, visible large amounts of exudate in the alveoli and bronchioles, alveolar focal hemorrhage. The control group B group pigs organization no abnormal changes.
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