Speculative Review on the Feasibility of Porcine Circovirus 2 Elimination.

Porcine circovirus 2 (PCV2) is still infecting pigs after almost 20 years of massive vaccination all over the world. Vaccines are highly effective at counteracting the clinical signs of systemic disease caused by PCV2 and can significantly reduce the number of subclinically infected pigs. However, current vaccination programs based on one single dose in piglets are insufficient to prevent infection in a proportion of animals. Moreover, systematic vaccination of the herd changes viral epidemiology and, consequently, can cause modifications in infection timing. Such a scenario may prompt intrauterine and piglet early infections, thus facilitating viral circulation even before vaccination takes place. Considering the demonstrated high vaccine efficacy, it would be legitimate to explore the possibility of eliminating PCV2 from swine herds, but only one attempt to eliminate the virus from a herd has been published so far. The present speculative review evaluates the existing scientific literature regarding the feasibility of getting rid of this virus under commercial farm conditions. The use of PCV2 vaccination in all swine populations within a herd and the implementation of regional or national control programs are foreseen as compulsory for the eventual successful elimination of this endemic viral infection.