Provided is a method for reducing viral load of porcine circovirus type 2 (PCV-2) in a pig by inducing an immune response against PCV-2 through the administration of an immunogenic composition comprising a PCV-2 antigen. A preferred antigen is a vector containing a PCV-2 nucleotide sequence. In a particularly preferred embodiment, the PCV-2 nucleotide sequence is ORF4, ORF13, or ORF4 and ORF13. In some embodiments, the immunogenic composition includes one or more additional pig pathogens.