SARS (severe acute respiratory syndrome virus, a coronavirus) immunogens, antigens, or epitopes, nucleic acid molecules encoding such immunogens, antigens, or epitopes; vectors containing such nucleic acid molecules, e.g., viral vectors such as baculovirus vectors, DNA vectors, such as DNA plasmid vectors, e.g., DNA plasmids that express a nucleic acid molecule in a mammalian cell, uses for such immunogens, antigens or epitopes and vectors, e.g., as an active component immunogenic, immunological or vaccine compositions, or to generate antibodies, such as monoclonal antibodies, and methods for making, and using such immunogens, antigens or epitopes, vectors, antibodies, including in methods for eliciting an immunological or immunogenic or vaccine response, as well as in assays or diagnostic kits or methods, are discussed, as well as a seamless fusion of sequences in a plasmid or vector, e.g., a sequence encoding a leader sequence and a sequence encoding a protein, epitope or immunogen or antigen.