To determine the efficacy of the pCEA-SARS-CoV tumor vaccine, mice were orally immunized with 1 × 108 pCEA- and pCEA-SARS-CoV-transformed S. typhimurium 14 days before inoculation with colon cancer CT26/CEA cells. Here, CEACAM5 is linked to malignant colon neoplasm.