Distinct PCV2 variants are circulating in commercial pig farms. How the vaccine induced immunity may affect PCV2 evolution?
These articles on porcine circovirus type 2 associated diseases present the most novel aspects, especially from the practical point of view, on etiology, pathogeny, epidemiology, diagnosis, treatment and prevention of the PCV2 infection.
Porcine circovirus (PCV2)
The benefit on antibiotic use is particularly clear when herds are multicontaminated by pathogenic virus and bacteria, allowing also to maintain animal welfare and operational productivity, but a good immunity against PCV2 is effective also in high health status herds.
Finding an occasional pig with PCVAD within a large population is not unexpected since vaccination compliance is rarely 100%. How does one assess impact of PCVAD in a vaccinated population?
It is a test that allows the verification of the carrying out and/or the quality of the vaccination in cases such as the entrance of piglets for their fattening.
The first cause of PCV vaccine failure is the purchase and use of generic vaccine of low quality and titre, but the exact cause of the failures can occur in various forms.
During 2012 PCV2 variants or mutants (mPCV2) appeared in the USA and were frequently associated with PCV-associated diseases. The possibility of lack of cross-protection of commercial vaccines against mPCV2 is now of major concern.
Reducing piglets mingling in farrowing and nursery facilities was found to delay the infectious process leading to a lower number of early infections. Clustering piglets by litter in small units after weaning also decreased significantly the probability of early infection.