Genomic sequence and virulence comparison of four Type 2 porcine reproductive and respiratory syndrome virus strains

► We compared the whole genomic sequence and virulence of 4 Type 2 PRRSV isolates. ► Genomic sequence evaluation indicates that SDSU73 is most similar to strain JA142. ► Nucleotide sequences of NADC30 and NADC31 are more similar to strain MN184. ► SDSU73, MN184, and NADC30 were all more virulent than NADC31.