Best practice and future challenges for vaccination against porcine circovirus type 2

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.