- Recently, a unique pox viral vector-based vaccine, PANVAC, has been shown to induce a CD4 and CD8 antigen-specific immune response against the tumor-associated antigens (TAAs), carcinoembryonic antigen (CEA) and mucin-1 (MUC-1). This vaccine also contains transgenes for three human T cell co-stimulatory molecules that can potentially augment an immune response