Protection of swine by live and inactivated vaccines prepared from a leader proteinase-deficient serotype A12 foot-and-mouth disease virus.
Previously, we demonstrated that a genetically engineered variant of foot-and-mouth disease virus (FMDV) serotype A12 lacking the leader proteinase-coding region (A12-LLV2) was attenuated and induced an immune response that partially protected cattle from FMD. In this study, A12-LLV2 was tested in swine as a live or chemically inactivated vaccine. Animals vaccinated with chemically inactivated A12-LLV2 or wild-type (WT) virus in oil adjuvant developed high levels of neutralizing antibodies and were protected from FMD upon challenge. Animals vaccinated with live A12-LLV2 did not exhibit signs of FMD, did not spread virus to other animals, developed a neutralizing antibody response and antibodies to nonstructural protein 3D, and were partially protected from FMD. Animals given a similar dose of chemically inactivated A12-LLV2 in the absence of adjuvant developed a poor immune response and were not protected from FMD, indicating that limited replication was responsible for the improved immune response found in animals vaccinated with live A12-LLV2. The results demonstrate the potential of A12-LLV2 as a live-attenuated vaccine as well as a safe source of antigen for chemically inactivated vaccines.
Chinsangaram
J
J
USDA, ARS, NAA, Plum Island Animal Disease Center, Greenport, NY 11944, USA.
Mason
P W
PW
Grubman
M J
MJ
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D005537:Aphthovirus / Q000145:classification / Q000235:genetics / Q000276:immunology*; D006224:Cricetinae; D010450:Endopeptidases / Q000172:deficiency / Q000235:genetics; D005260:Female; D005536:Foot-and-Mouth Disease / Q000517:prevention & control*; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control*; D014613:Vaccines, Attenuated / Q000276:immunology / Q000627:therapeutic use; D015164:Vaccines, Inactivated / Q000276:immunology / Q000627:therapeutic use; D014765:Viral Vaccines / Q000276:immunology / Q000627:therapeutic use*; D014779:Virus Replication / Q000502:physiology
D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D015164:Vaccines, Inactivated; D014765:Viral Vaccines; D010450:Endopeptidases