|FULTON, R - Oklahoma State University|
|SALIKI, J - University Of Georgia|
|LANDIS, C - Oklahoma State University|
|BURGE, L - Oklahoma State University|
|PAYTON, M - Oklahoma State University|
Submitted to: Virus Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/11/2017
Publication Date: 5/2/2017
Citation: Fulton, R.W., Neill, J.D., Saliki, J.T., Landis, C., Burge, L.J., Payton, M.E. 2017. Genomic and antigenic characterization of bovine parainfluenze-3 viruses in the United States including modified live virus vaccine (MLV) strains and field strains from cattle. Virus Research. 235:77-81. https://doi.org/10.1016/j.virusres.2017.04.009.
Interpretive Summary: Bovine parainfluenza 3 virus (BPI3V) is a viral pathogen often associated with bovine respiratory disease. It is also a common component of multivalent, modified live bovine viral vaccines (MLV) that are sold in this country. Recently it was found that there were two types of BPI3V circulating here that previously had been described only in Australia and Asia. Using molecular tests including real time PCR and viral genome sequencing, BPI3V strains could be separated into BPI3V types A, B, and C. Isolates from cattle with bovine respiratory disease clinical signs and commercial vaccines with MLV BPI3V were typed using these molecular tests. All MLV strains tested belonged to type BPI3V A. In most cases BPI3V field strains from calves receiving MLV vaccines were types B or C. Antigenic differences between the BPI3V types were indicated by lower antibody levels against BPI3V C strains than BPI3V A in serums from cattle receiving MLV BPI3V A vaccines. This study further demonstrates that there is antigenic variability amongst BPI3V types. In addition, molecular tests should be performed to differentiate field from vaccine strains. Current BPI3V type A vaccines should be evaluated for efficacy against types BPI3V B and BPI3V C.
Technical Abstract: This study investigated the genetic and antigenic characterization of parainfluenza-3 virus (PI3V) of cattle. Using molecular tests including real time PCR and viral genome sequencing, PI3V strains could be separated into PI3V types, including PI3V A, PI3V B, and PI3V C. Isolates from cattle with bovine respiratory disease clinical signs and commercial vaccines in the U.S. with MLV PI3V were typed using these molecular tests. All the MLV vaccine strains tested were PI3V A. In most cases PI3V field strains from calves receiving MLV vaccines were types heterologous to the vaccine type A. Also antigenic differences were noted as PI3V C strains had lower antibody levels than PI3V A in serums from cattle receiving MLV PI3V A vaccines. This study further demonstrates there is genetic variability of U.S. PI3V strains and also antigenic variability. In addition, isolates from cattle with BRD signs and receiving MLV vaccines may have heterologous types to the vaccines, and molecular tests should be performed to differentiate field from vaccine strains. Potentially the efficacy of current PI3V A vaccines should be evaluated with other types such a PI3V A and PI3V B.