3.4 Immunization of recombinant TM-1 protected chicken against MG infection.
We next tested if twice vaccination could adequately protect chickens from MG infection by monitoring change of clinical sings and bodyweight after MG virulent strain inoculation. After two weeks of challenge, the mean severity-based clinical scores in control and WT group was 2.73±0.28 and 2.65±0.26, which were significantly higher than groups vaccinated with recombinant TM-1 and MG attenuated vaccine with a score of 0.72±0.13 and 0.58±0.19 respectively (Fig.5), indicating an efficient systemic protection against MG virus infection. Additionally, Bodyweight remained similar among all groups up to week 5, suggesting vaccination of recombinant TM-1 antigen and attenuated MG vaccine did not affect gaining weight (Table 1). Nevertheless, chickens in TM-1 and attenuated MG vaccine groups gained significantly more weight than those in control group one week after MG virus challenge (Table 1), confirming the protective effect of recombinant TM-1 antigen prior to MG infection. Scores of air sac lesion showed similar pattern. After two weeks of MG virus challenge, presence of lesions was found significantly more in control groups compared to other two groups, suggesting the recombinant TM-1 vaccine specifically protects air sac in avian respiratory system (Table 2).