Evaluation of the new commercial recombinant chimeric subunit vaccine PRRSFREE in challenge with heterologous types 1 and 2 porcine reproductive and respiratory syndrome virus.
The objective of this study was to evaluate a new recombinant chimeric vaccine against porcine reproductive and respiratory syndrome virus (PRRSV). The subunit vaccine, PRRSFREE, from Reber Genetics, Taiwan, Republic of China, is based on a plasmid containing a detoxifiedPseudomonasexotoxin carrying open reading frame (ORF) 7, 1b, and 5 and 6 chimeric subunits of types 1 and 2 PRRSV. Pigs were injected intramuscularly with 2.0 mL of the vaccine at 21 and 42 d of age, according to the manufacturer's recommendation. At the age of 63 d the pigs were inoculated intranasally with either type 1 or type 2 PRRSV. Regardless of the genotype of the challenging PRRSV, the vaccinated challenged pigs had significantly lower (P< 0.05) mean rectal temperature, respiratory score, lung lesion score, and amount of PRRSV antigen within areas of interstitial pneumonia, along with overall lower levels of viremia due to type 1 or type 2 PRRSV compared with the unvaccinated challenged pigs. The vaccinated challenged pigs also had significantly higher (P< 0.05) numbers of interferon-γ secreting cells compared with the unvaccinated challenged pigs. This study demonstrated that the new vaccine provides protection against respiratory disease from heterologous types 1 and 2 PRRSV challenge in growing pigs.
Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, 151-742, Seoul, Republic of Korea.
Jiwoon
J
Jeong
Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, 151-742, Seoul, Republic of Korea.
Changhoon
C
Park
Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, 151-742, Seoul, Republic of Korea.
Kyuhyung
K
Choi
Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, 151-742, Seoul, Republic of Korea.
Chanhee
C
Chae
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D008168:Lung / Q000821:virology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000517:prevention & control*; D019316:Porcine respiratory and reproductive syndrome virus / Q000145:classification*; D012367:RNA, Viral; D011994:Recombinant Proteins / Q000276:immunology*; D013552:Swine; D022223:Vaccines, Subunit / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*; D014766:Viremia
D000914:Antibodies, Viral; D012367:RNA, Viral; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; D014765:Viral Vaccines