A novel HLA-A2.1-specific SARS coronavirus (SARS-CoV) nucleocapsid (N) protein epitope (N220-N228 LALLLLDRL) able to activate cytotoxic T cells in vitro has been identified. 2. When used with a single-chain-trimer system, the SARS-CoV N protein epitope (N220-N228 LALLLLDRL) can stimulate a cytotoxic T-cell response against N-protein expressing cells in the HLA-A2.1K(b) transgenic mouse model.