Efficacy of AMERVAC®- PRRS after heterologous challenge with a pathogenic Chinese-like PRRS virus

Throughout the second half of 2006, large-scale, devastating outbreaks of porcine reproductive and respiratory syndrome (PRRS) affected several provinces of China¹.

That epidemic was linked to a hypervirulent genotype-II PRRS virus (PRRSV) harboring a distinctive deletion¹. Economic losses from those outbreaks results from deaths but also from loss weight and impaired performance. Control of such outbreaks proved difficult and those hypervirulent strains spread in Asia.

At present, genotype I strains are also present in different countries of Asia. AMERVACR-PRRS (a genotype-I vaccine) is being marketed in Asia for the prevention PRRS virus infections. Is feasible that some herds vaccinated with AMERVACR-PRRS could confront the infection with a hypervirulent Asian strain. The present study was intended to determine if vaccination with AMERVACR-PRRS could produce some beneficial effect on performance of pigs infected with the hypervirulent strain.

Merce Roca¹ Sergi Bruguera¹ Mariona Gimeno², ³ Ivan Diaz2 Ivan Galindo²,³ Joaquim Segales², ³Enric Mateu², ³ Natalia Bello¹, David Llopart¹, Jaime Maldonado¹, Ricard March¹