Antibody repertoire development in fetal and neonatal piglets. XV. Porcine circovirus type 2 infection differentially affects serum IgG levels and antibodies to ORF2 in piglets free from other environmental factors

► PCV2 does not cause generalized polyclonal B cell activation. ► Infected piglets make strong IgG responses to ORF2 of PCV2. ► PCV2 would be a poor adjuvant for a killed PCV2 vaccine. ► Compelling evidence that PCV2 is immunosuppressive was not found. ► Differences in Ig levels and anti-ORF2 responses may be genetic.