Generation by reverse genetics of an effective attenuated Newcastle disease virus vaccine based on a prevalent highly virulent Chinese strain.
OBJECTIVE
To investigate whether the differences between the circulating Newcastle disease virus (NDV) isolates and the used vaccine might account for the current ND outbreaks in vaccinated poultry flocks.


RESULTS
A reverse genetics system using prevalent genotype VIId isolate SG10 was constructed and a mutant virus, named aSG10, was developed by changing the virulent F protein cleavage site motif "(112)RRQKR↓F(117)" into an avirulent motif "(112)GRQGR↓L(117)". The attenuated pathogenicity of aSG10 was confirmed from the mean death time and intracerebral pathogenicity index. aSG10 and LaSota both protected vaccinated birds from death after challenge with highly virulent genotype VII NDV, strain SG10. However, aSG10 significantly reduced the challenge virus shedding from the vaccinated birds compared to LaSota vaccine. We also generated a recombinant virus, aSG10-enhanced green fluorescent protein (EGFP), which expresses EGFP. aSG10-EGFP stably expressed EGFP for at least 10 passages.


CONCLUSIONS
The mutant, aSG10, can be safely used as a vaccine vector and is a potential vaccine candidate in increasing the protective efficacy for the control of current ND epidemic in China.
Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, China, studenta@126.com.
Meng-Meng
MM
Liu
Jin-Long
JL
Cheng
Xiao-Hui
XH
Yu
Zhuo-Ming
ZM
Qin
Fu-Lin
FL
Tian
Guo-Zhong
GZ
Zhang
D000818:Animals; D001715:Bird Diseases / Q000453:epidemiology / Q000821:virology; D001921:Brain / Q000473:pathology; D002681:China / Q000453:epidemiology; D006801:Humans; D009521:Newcastle Disease / Q000453:epidemiology / Q000821:virology; D009522:Newcastle disease virus / Q000235:genetics* / Q000276:immunology* / Q000472:pathogenicity; D011200:Poultry; D011201:Poultry Diseases / Q000453:epidemiology / Q000517:prevention & control / Q000821:virology; D059386:Reverse Genetics; D016019:Survival Analysis; D014613:Vaccines, Attenuated / Q000009:adverse effects / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D014614:Vaccines, Synthetic / Q000009:adverse effects / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D014765:Viral Vaccines / Q000009:adverse effects / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification
D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014765:Viral Vaccines