Association of concurrent porcine circovirus (PCV) 2a and 2b infection with PCV associated disease in vaccinated pigs

Gerber, Priscilla F.; Johnson, J D; Shen, Huigang; Striegel, Dave; Xiao, Chao-Ting; Halbur, Patrick G.; Opriessnig, Tanja

doi:10.1016/j.rvsc.2013.06.004

Cited by 23 publications

(20 citation statements)

References 30 publications

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“…The differential PCR assay does not react with PCV2c due to a primer mismatch. Selected PCV2 PCR-positive samples were sequenced by using a conventional PCR covering the entire ORF2 as described previously [18] at the Iowa State University DNA Facility, Ames, IA, USA.…”

Section: Methodsmentioning

confidence: 99%

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A commercial porcine circovirus (PCV) type 2a-based vaccine reduces PCV2d viremia and shedding and prevents PCV2d transmission to naïve pigs under experimental conditions

Opriessnig

Xiao

Halbur

et al. 2017

Vaccine

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Porcine circovirus type 2 (PCV2) vaccination has been effective in protecting pigs from clinical disease and today is used extensively. Recent studies in vaccinated populations indicate a major PCV2 genotype shift from the predominant PCV2 genotype 2b towards 2d. The aims of this study were to determine the ability of the commercial inactivated PCV2a vaccine Circovac® to protect pigs against experimental challenge with a 2013 PCV2d strain and prevent transmission. Thirty-eight pigs were randomly divided into four groups with 9–10 pigs per group: NEG (sham-vaccinated, sham-challenged), VAC (PCV2a-vaccinated, sham-challenged), VAC + CHAL (PCV2a-vaccinated and PCV2d-challenged), and CHAL (sham-vaccinated, PCV2d-challenged). Vaccination was done at 3 weeks of age using Circovac® according to label instructions. The CHAL and VAC + CHAL groups were challenged with PCV2d at 7 weeks of age and all pigs were necropsied 21 days post-challenge (dpc). The VAC-CHAL pigs seroconverted to PCV2 by 21 days post vaccination (dpv). At PCV2d challenge on 28 dpv, 3/9 VAC and 1/9 VAC + CHAL pigs were seropositive. NEG pigs remained seronegative for the duration of the study. Vaccination significantly reduced PCV2d viremia (VAC + CHAL) at dpc 14 and 21, PCV2d fecal shedding at dpc 14 and 21 and PCV2d nasal shedding at dpc 7, 14 and 21 compared to CHAL pigs. Vaccination significantly reduced mean PCV2 antigen load in lymph nodes in VAC + CHAL pigs compared to CHAL pigs. When pooled serum or feces collected from VAC + CHAL and CHAL pigs at dpc 21 were used to expose single-housed PCV2 naïve pigs, a pooled fecal sample from CHAL pigs contained infectious PCV2 whereas this was not the case for VAC + CHAL pigs suggesting reduction of PCV2d transmission by vaccination. Under the study conditions, the PCV2a-based vaccine was effective in reducing PCV2d viremia, tissue loads, shedding and transmission indicating that PCV2a vaccination should be effective in PCV2d-infected herds.

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Section: Methodsmentioning

confidence: 99%

“…Furthermore, pigs are often co-infected with multiple PCV2 strains [18], [19]. Since the beginning of this decade a newly recognized genotype, PCV2d, emerged in essentially all large pig populations in North America, South America, Europe and Asia [9], [20].…”

Section: Introductionmentioning

confidence: 99%

A commercial porcine circovirus (PCV) type 2a-based vaccine reduces PCV2d viremia and shedding and prevents PCV2d transmission to naïve pigs under experimental conditions

Opriessnig

Xiao

Halbur

et al. 2017

Vaccine

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“…The distribution of PCV2 genotypes continues to evolve in the vaccinated population, as reflected by the change in genotype prevalence to PCV2d [59]. Concurrent infection with PCV2a and PCV2b genotypes is thought to be a potentiating factor in the development of clinical disease and PCV-AD cases, with concurrent PCV2a and PCV2b infections also being observed in the field [94]. …”

Section: Pcv2 Vaccinesmentioning

confidence: 99%

Porcine Circovirus Type 2 (PCV2) Vaccines in the Context of Current Molecular Epidemiology

Karuppannan

Opriessnig

2017

Viruses

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119

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Porcine circovirus type 2 (PCV2) is an economically important swine pathogen and, although small, it has the highest evolution rate among DNA viruses. Since the discovery of PCV2 in the late 1990s, this minimalistic virus with a 1.7 kb single-stranded DNA genome and two indispensable genes has become one of the most important porcine pathogens, and presently is subjected to the highest volume of prophylactic intervention in the form of vaccines in global swine production. PCV2 can currently be divided into five different genotypes, PCV2a through PCV2e. It is well documented that PCV2 continues to evolve, which is reflected by changes in the prevalence of genotypes. During 2006, commercial vaccines for PCV2 were introduced on a large scale in a pig population mainly infected with PCV2b. Since 2012, the PCV2d genotype has essentially replaced the previously predominant PCV2b genotype in North America and similar trends are also documented in other geographic regions such as China and South Korea. This is the second major PCV2 genotype shift since the discovery of the virus. The potential increase in virulence of the emergent PCV2 genotype and the efficacy of the current vaccines derived from PCV2a genotype against the PCV2d genotype viruses has received considerable attention. This review attempts to synthesize the understanding of PCV2 biology, experimental studies on the antigenic variability, and molecular epidemiological analysis of the evolution of PCV2 genotypes.

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“…Although, the current available commercial vaccines have proven highly effective in inducing protective immunity under field conditions Kixmöller et al, 2008;Segales et al, 2009;Pejsak et al, 2010;Beach and Meng, 2012;Gerber et al, 2013;Opriessnig et al, 2014;Segales 2014), vaccination does not provide sterile immunity and vaccinated animals can still be infected with the virus (Kekarainen et al, 2010). Thus, PCV2 is still circulating in vaccinated farms, and the high mutation rates, resembling those of RNA viruses (Firth et al, 2009) together with vaccine pressure might support the evolution of new PCV2 strains with the tendency to evade vaccination (Lv et al, 2014;Kekarainen et al, 2014, Segales 2014.…”

Section: Introductionmentioning

confidence: 99%

Genetic variability of porcine circovirus 2 (PCV2) field isolates from vaccinated and non-vaccinated pig herds in Germany

Reiner

Hofmeister

Willems

2015

Veterinary Microbiology

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Association of concurrent porcine circovirus (PCV) 2a and 2b infection with PCV associated disease in vaccinated pigs

Cited by 23 publications

References 30 publications

A commercial porcine circovirus (PCV) type 2a-based vaccine reduces PCV2d viremia and shedding and prevents PCV2d transmission to naïve pigs under experimental conditions

A commercial porcine circovirus (PCV) type 2a-based vaccine reduces PCV2d viremia and shedding and prevents PCV2d transmission to naïve pigs under experimental conditions

Porcine Circovirus Type 2 (PCV2) Vaccines in the Context of Current Molecular Epidemiology

Genetic variability of porcine circovirus 2 (PCV2) field isolates from vaccinated and non-vaccinated pig herds in Germany

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