AUTHOR=Trevisan Giovani , Magstadt Drew , Woods Amy , Sparks Joel , Zeller Michael , Li Ganwu , Krueger Karen M. , Saxena Anugrah , Zhang Jianqiang , Gauger Phillip C. 

TITLE=A recombinant porcine reproductive and respiratory syndrome virus type 2 field strain derived from two PRRSV-2-modified live virus vaccines

JOURNAL=Frontiers in Veterinary Science

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1149293

DOI=10.3389/fvets.2023.1149293

ISSN=2297-1769

ABSTRACT=A porcine reproductive and respiratory syndrome virus (PRRSV) type 2 (PRRSV-2) isolate was obtained from lung samples collected from a 4.5-month-old pig placed in a wean-to-finish site located in Indiana, United States of America (USA), although no gross or microscopic lesions suggestive of PRRSV infection were observed in lung tissue. Phylogenetic and molecular evolutionary analysis based on the obtained virus sequences indicated that the isolate PRRSV USA/IN105404/2021 was a natural recombinant from Ingelvac PRRS® MLV and Prevacent® PRRS, both PRRSV-2 modified live virus vaccines commercially available in the USA. This study is the first to report the detection of a PRRSV-2 recombinant consisting entirely of 2 modified live virus vaccine strains under field conditions. Based on clinical data and the absence of lung lesions, this recombinant PRRSV-2 strain was not virulent in swine, although its pathogenicity needs to be confirmed by a clinical trial.