Comparison of efficacy of commercial one dose and two dose PCV2 vaccines using a mixed PRRSV–PCV2–SIV clinical infection model 2–3-months post vaccination
ABSTRACT The study objectives were to compare the duration of immunity of commercially available, one and two dose, killed porcine circovirus type 2 (PCV2) vaccines. Sixty, 3.5-week-old pigs were randomly divided into six treatment groups: one dose vaccines (FDAH-1, BIVI-1), two dose vaccines (Intervet-2, FDAH-2), and non-vaccinated negative and positive controls. Tissue homogenate challenge was conducted 63 (two doses) or 84 (one dose) days post vaccination. Viremia was reduced by 78.5% in pigs vaccinated with one dose and by 97.1% in pigs vaccinated with two dose products and overall microscopic lymphoid lesions were reduced by 78.7% and 81.8%, respectively.
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ABSTRACT: Background Porcine circovirus type 2 (PCV2) is an etiological agent of porcine circovirus diseases (PCVDs). Post-weaning multisystemic wasting syndrome (PMWS) as the most important PCVD is considered a multifactorial disease. It was demonstrated that not only PCV2 but several viruses are associated with PMWS. Studies of viral co-infections in PMWS pigs led often to controversial results. The aim of this work was to determine the presence of emerging (PRRSV), re-emerging (PTV) and newly-emerging (TTSuV1, TTSuV2, PBoV1) viruses in samples of dead pigs suffering from PMWS. The impact of vaccination against PCV2 and the influence of age on the occurrence of single and multiple viral infections in pigs were also investigated.ResultsViruses were detected by PCR, RT-PCR and real-time PCR in the pooled tissue samples (lymph nodes, liver and spleen) of pigs with PMWS (n¿=¿56) which were divided into three groups: suckling piglets, post-weaning pigs and fattening pigs. In addition, lymph node samples were collected from apparently healthy fattening pigs (n¿=¿59). The effect of vaccination against PCV2 with Ingelvac CircoFlex vaccine was also investigated. Between non-vaccinated pigs, the highest prevalence of individual viruses and multiple viral infections were found in diseased post-weaning and fattening animals with PMWS. Severe clinical disease was observed in swine co-infected with PCV2 and PRRSV. The prevalence of TTSuV1 and TTSuV2 was high in all groups of pigs and did not appear to have a significant effect on the syndrome. Simultaneous infection with TTSuV1 and PBoV1 was frequently confirmed in pigs with PMWS. No healthy pig was found to be infected with PRRSV, PTV or PBoV1. Vaccination against PCV2 did not influence the prevalence of TTSuVs, but significantly protected pigs against multiple viral infections.Conclusions Post-weaning PMWS pigs were more often co-infected with viral pathogens than suckling or fattening pigs. Co-infection with PRRSV enforces clinical signs of PMWS, the influence of other viral co-infections is not clear. Vaccination against PCV2 significantly reduced viral co-infections in pigs.BMC Veterinary Research 09/2014; 10(1):221. DOI:10.1186/s12917-014-0221-8 · 1.74 Impact Factor
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ABSTRACT: Porcine circovirus type 2 (PCV2)-systemic disease (SD) (initially named as postweaning multisystemic wasting syndrome) was discovered as an occasional disease affecting postweaning pigs in North-America by mid-1990s. Soon afterward, it was noticed as a devastating disease worldwide. Such scenario prompted to develop vaccine prototypes that worked fairly well under experimental conditions. In spite of the multifactorial nature of the PCV2-SD, the first commercialized vaccines containing inactivated or chimeric PCV2 viruses or PCV2 Cap protein represented by far the best system to control the disease under farm conditions. Moreover, vaccination of non-clinically affected pigs demonstrated a significant improvement of average daily weight gain and, in consequence, the economic importance of the PCV2-subclinical infection. In the present review, a comprehensive overview on PCV2 vaccines and best practices on PCV2 vaccination strategies are presented and discussed.Expert Review of Vaccines 11/2014; 14(3). DOI:10.1586/14760584.2015.983084 · 4.22 Impact Factor
01/2012, Degree: PhD, Supervisor: Hans Nauwynck