Abstract: To investigate the impact of vaccination with highly pathogenic porcine reproductive and respiratory syndrome(HP-PRRS) attenuated vaccine(TJM-F92 strain) at gestation of 60 days on immune competency for their piglets. The field test was performed using sows vaccinated with HP-PRRS attenuated vaccine （TJM-F92 strain） as the immunized group, and the unimmunized sows were injected with saline under the same condition as control. The serum and anti-coagulated blood was taken randomly from their piglets at days 10, 20 and 30, for detection of maternal antibodies against PRRSV, CSFV, PRV by ELISA, and T, B lymphocyte function by MTT assay, NO level by Griess’s method and lysozyme activity by agar plate method. The results showed that the vaccination with HP-PRRS attenuated vaccine （TJM-F92 strain） on the sows at gestation of 60 days enhanced the immunologic defense ability for their piglets against PRRSV, the maternal antibody against PRRSV was significantly higher than that of control group at day 10(P＜0.05), and it was benefit for the ability of anti-CSFV and anti-PRV abilities, the blocking antibody against CSFV at day 10 was extremely significantly higher and the infectious antibody against PRV(gE) at day 20 was extremely significantly lower compared with the control group(P＜0.01). The results also showed no significant immunosuppression on T, B lymphocyte transformation assay, NO level and lysozyme content in serum from the piglets between two groups(P＞0.05). The results indicated that the vaccination with HP-PRRS attenuated live vaccine （TJM-F92 strain） at gestation increased maternal antibodies against PRRSV and CSFV, whereas no suppression on the non-specific immunity and T, B cell immunity in their piglets.

Key words:

highly pathogenic porcine reproductive and respiratory syndrome virus(HPmso-bidi-font-family: 宋体" lang="EN-US">-PRRSV); maternal antibody; classical swine fever virus