Development of a live attenuated vaccine candidate against duck Tembusu viral disease
Guoxin Li1, Xuyuan Gao1, Yali Xiao1
1Department of avian infectious disease, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China.
Abstract:
Duck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that is causing massive economic loss in the Chinese duck industry. To obtain a live vaccine candidate against the disease, the DTMUV isolate FX2010 was passaged serially in chicken embryo fibroblasts (CEFs). Characterization of FX2010-180P revealed that it was unable to replicate efficiently in chicken embryonated eggs, nor intranasally infect mice or shelducks at high doses of 5.5log10 tissue culture infectious doses (TCID50). FX2010-180P did not induce clinical symptoms, or pathological lesions in ducks at a dose of 5.5log10TCID50. The attenuation of FX2010-180P was due to 19 amino acid changes and 15 synonymous mutations. Importantly, FX2010-180P elicited good immune responses in ducks inoculated at low doses (3.5log10TCID50) and provided complete protection against challenge with a virulent strain. These results indicate that FX2010-180P is a promising candidate live vaccine for prevention of duck Tembusu viral disease.
