Comparative Immunization in BALB/c Mice with Recombinant Replication-Defective Adenovirus Vector and DNA Plasmid Expressing a SARS-CoV Nucleocapsid Protein Gene

In order to investigate immunogenicity in the induction of humoral and cellular immune responses, severe acute respiratory syndrome associated coronavirus (SARS-CoV)-N gene recombinant replication-defective adenoviral vector, rAd-N, was generated and immunized BALB/c mice in a pcDNA3.1-N prime-rAd-N boost regimen. After humoral and cellular immune response detection, different levels of SARS-CoV N protein specific antibodies and interferon-γ (IFN-γ) secretion are shown compared to controls. The humoral immune response was induced more effectively by the DNA priming and recombinant adenovirus boosting regimen. There is a significant difference between heterogeneous and homologous vaccinations. The heterogeneous combinations were all higher than those of the homologous combinations in the induction of anti-N antibody response. Among the three heterogeneous