Engineering foot-and-mouth disease viruses with improved growth properties for vaccine development.
BACKGROUND
No licensed vaccine is currently available against serotype A foot-and-mouth disease (FMD) in China, despite the isolation of A/WH/CHA/09 in 2009, partly because this strain does not replicate well in baby hamster kidney (BHK) cells.


RESULTS
A novel plasmid-based reverse genetics system was used to construct a chimeric strain by replacing the P1 gene in the vaccine strain O/CHA/99 with that from the epidemic stain A/WH/CHA/09. The chimeric virus displayed growth kinetics similar to those of O/CHA/99 and was selected for use as a candidate vaccine strain after 12 passages in BHK cells. Cattle were vaccinated with the inactivated vaccine and humoral immune responses were induced in most of the animals on day 7. A challenge infection with A/WH/CHA/09 on day 28 indicated that the group given a 4-µg dose was fully protected and neither developed viremia nor seroconverted to a 3ABC antigen.


CONCLUSIONS
Our data demonstrate that the chimeric virus not only propagates well in BHK cells and has excellent antigenic matching against serotype A FMD, but is also a potential marker vaccine to distinguish infection from vaccination. These results suggest that reverse genetics technology is a useful tool for engineering vaccines for the prevention and control of FMD.
State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.
Haixue
H
Zheng
Jianhong
J
Guo
Ye
Y
Jin
Fan
F
Yang
Jijun
J
He
Lv
L
Lv
Kesan
K
Zhang
Qiong
Q
Wu
Xiangtao
X
Liu
Xuepeng
X
Cai
D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood / Q000276:immunology; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology* / Q000517:prevention & control; D002460:Cell Line; D006224:Cricetinae; D005536:Foot-and-Mouth Disease / Q000276:immunology* / Q000517:prevention & control; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics* / Q000254:growth & development / Q000276:immunology*; D023061:Gene Order; D051379:Mice; D010957:Plasmids / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics* / Q000276:immunology*
D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D012367:RNA, Viral; D015164:Vaccines, Inactivated; D014765:Viral Vaccines