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).