Veterinary and Biomedical Sciences, Department of


Date of this Version



Vu HLX, Ma F, Laegreid WW, Pattnaik AK, Steffen D, Doster AR, Osorio FA. 2015. A synthetic porcine reproductive and respiratory syndrome virus strain confers unprecedented levels of heterologous protection. J Virol 89:12070 –12083. doi:10.1128/JVI.01657-15.


Copyright © 2015, American Society for Microbiology.


Current vaccines do not provide sufficient levels of protection against divergent porcine reproductive and respiratory syndrome virus (PRRSV) strains circulating in the field, mainly due to the substantial variation of the viral genome. We describe here a novel approach to generate a PRRSV vaccine candidate that could confer unprecedented levels of heterologous protection against divergent PRRSV isolates. By using a set of 59 nonredundant, full-genome sequences of type 2 PRRSVs, a consensus genome (designated PRRSV-CON) was generated by aligning these 59 PRRSV full-genome sequences, followed by selecting the most common nucleotide found at each position of the alignment. Next, the synthetic PRRSV-CON strain was generated through the use of reverse genetics. PRRSV-CON replicates as efficiently as our prototype PRRSV strain FL12, both in vitro and in vivo. Importantly, when inoculated into pigs, PRRSV-CON confers significantly broader levels of heterologous protection than does wild-type PRRSV. Collectively, our data demonstrate that PRRSV-CON can serve as an excellent candidate for the development of a broadly protective PRRSV vaccine.