An oral mucosal DNA vaccine for SARS coronavirus infections.

1. When different forms of SARS coronavirus (SARS-CoV) spike protein-based vaccines for generation of a neutralising antibody response to SARS-CoV were injected into a mouse model, all the mice immunised with intramuscular tPA-optimised 800 DNA vaccine boosted with intraperitoneal recombinant spike polypeptide generated by Escherichia coli and intramuscular CTLA4Hinge SARS800 DNA vaccine boosted with intraperitoneal S-peptide had neutralising antibody titres of>1:1280.2. This observation may have major practical value for field studies, such as the immunisation of civet cats, as the cost of recombinant proteins produced by E coli is much lower than those produced by eukaryotic systems.3. This study indicates that the type of vaccine used for priming is crucial for determining the type of immune response developed.Subsequent doses will boost the immune response generated by the first dose of vaccine.