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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #298896
Title: Efficacy of type 2 PRRSV vaccine against Chinese and Vietnamese HP-PRRSV challenge in pigs

Author
item Lager, Kelly
item Schlink, Sarah
item Brockmeier, Susan
item Miller, Laura
item HENNINGSON, JAMIE - Kansas State University
item Kappes, Matthew
item Kehrli Jr, Marcus
item Loving, Crystal
item GUO, BAOQUING - Iowa State University
item SWENSON, SABRINA - Animal And Plant Health Inspection Service (APHIS)
item YANG, HAN-CHUN - China Agricultural University
item Faaberg, Kay

Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2014
Publication Date: 11/12/2014
Citation: Lager, K.M., Schlink, S.N., Brockmeier, S.L., Miller, L.C., Henningson, J.N., Kappes, M.A., Kehrli, M.E., Loving, C.L., Guo, B., Swenson, S.L., Yang, H., Faaberg, K.S. 2014. Efficacy of type 2 PRRSV vaccine against Chinese and Vietnamese HP-PRRSV challenge in pigs. Vaccine. 32(48):6457–6462.

Interpretive Summary: Porcine reproductive and respiratory syndrome (PRRS) is the number one disease problem for U.S. swine as well as in most pork producing countries. It is caused by a virus (PRRSV) which induces reproductive losses in the sow herd and respiratory disease in growing pigs. Depending on husbandry, immune status of the herd, and virulence of the virus isolate (disease causing capabilities), the severity of disease and magnitude of economic loss can be variable. Although vaccines are available, there use is not always successful indicating a lack of cross-protection between vaccine strains and circulating viruses in the field. To date, there is no clear method to determine if a vaccine confers protection against a specific isolate except for empirical animal studies. In 2006, a new lineage of PRRSV emerged in Chinese swine herds that were suffering dramatic losses resulting in those viruses being described as "Highly Pathogenic PRRSV" (HP-PRRSV). Experimental reproduction of severe disease with HP-PRRSV isolates and virus that was derived from HP-PRRSV clones, demonstrated the causal role of this virus in the regional epidemics. This paper reports the efficacy of a U.S. commercially available PRRSV vaccine in young pigs against challenge with a Chinese and Vietnamese HP-PRRSV isolate. Results show the vaccine could induce partial protection indicating the potential for vaccine use in control of HP-PRRSV infections control.

Technical Abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) causes significant reproductive losses in the sow herd and respiratory disease in growing pigs. It is a virus that belongs to the family Arteriviridae virus for which there are two major genotypes, Type 1 represented by Lelystad virus, the European prototype virus, and Type 2 represented by the North American prototype virus, VR-2332. Depending on husbandry, immune status of the herd, and virulence of the isolate, the severity of disease and magnitude of economic loss can be variable. Vaccine use is not always successful indicating a lack of cross-protection between vaccine strains and circulating wild-type viruses. To date, there is no clear method to demonstrate if a vaccine confers protection against a specific isolate except for empirical animal studies. In 2006, a new lineage of PRRSV emerged in Chinese swine herds that were suffering dramatic losses resulting in those viruses being described as "Highly Pathogenic PRRSV" (HP-PRRSV). Analysis of the isolates revealed this virus was derived from endemic Type 2 PRRSV. Experimental reproduction of severe disease with HP-PRRSV isolates and virus derived from HP-PRRSV clones demonstrated the causal role of this virus. Recently, partial heterologous protection has been reported for Type 1 and Type 2 attenuated PRRSV vaccines against challenge by different Chinese HP-PRRSV isolates providing some hope for reducing economic loss. This paper reports the efficacy of a commercially available Type 2 attenuated vaccine in young pigs against heterologous challenge with a Chinese and Vietnamese HP-PRRSV isolate demonstrating the potential for vaccine use in control of HP-PRRSV infections control.