Evaluation The Immune Effect Of Foot And Month Disease Vaccines

Foot and mouth disease(FMD) is an acute and contagious infectious virus disease that can infect cloven-hoofed animals, it’s characteristics is quick outbreak with short latency period and wide transmission. In China, vaccination is the main control measure to prevent animals from attacking of FMD virus as vaccines can help susceptible cattle to maintain high level of antibody. Vaccination program is very important that we should take into consideration. However, there are few vaccination program studies were reported till now. Since 1998, mass vaccination have been carried out on cattle and sheep against FMD in Zhangjiajie, mainly inoculated with O-type FMDV vaccines. O-type and Asia type I FMDV bivalent vaccines were demanded to immunize cattle and sheep since the beginning of 2007. Making a proper new bivalent vaccination program needs more data to support.In this study, liquid-phase blocking ELISA was used as the main testing method to detect FMDV antibody, including the level of maternal antibodies and the effect of primary immunization, as well as different inoculation programs after primary immunization and immunization frequency in a year. Results showed that maternal antibody of newborn calves arose after a week and reached the summit at 21 days which can last 60 days; however, the antibody level and positive rate declined after 90 days. Based on this, we can set the first shot at 90 days. After the primary immunization, the level of antibody will reach the summit at 15days later, and after 60 days, although the antibody positive rate seems proper after vaccinated with O type FMD. but the antibody positive incidence of Asia type I turns to negative after 30 days later, so the second vaccination should be given at 120 days and the third shot at 210 days is the best with significant difference (P<0.01). First immunization at 90 days and second shot at 120 days is significantly better than first shot at 90 days with second shot at 150 days (P<0.05). The research established a scientific and reasonable vaccination program of inactivated vaccines against FMD virus for intensive farms in Xiangxi area:vaccination three times a year that first immunization was given at 90 days of age, second dose was given 1 month later, and then the third one got 4 months apart; but for the scattering raising-holders can do the vaccination with bivalent vaccines three times a year and the second shot can be given at 120 days and then the third one got 6 months apart.