Field investigations of perceived PCV2 vaccine failures and experimental challenge trials that support transitioning to a PCV2b-based vaccine

摘要

Porcine circovirus associated disease (PCVAD) is now an important and globally recognized disease. The predominate genotype of porcine circovirus type 2 (PCV2) in the pig population today is PCV2b' yet the currently available commercial vaccines are PCV2a-based.2 PCV2 vaccines are widely accepted as being effective in controlling PCVAD; however, perceived PCV2 vaccine failures occur on a regular basis. The first objective of this study was to summarize findings in two cases of PCVAD outbreaks in vaccinated herds. To our knowledge, a direct side-by side comparison of the efficacy of both genotype 2a and 2b-based PCV2 vaccines has not been conducted to date. Therefore, the second objective of this study was to compare the ability of PCV2a- and PCV2b-based vaccines to control PCV2b viremia in a challenge model that mimics the US field situation.