Neutralizing antibody against severe acute respiratory syndrome (SARS)‐coronavirus spike is highly effective for the protection of mice in the murine SARS model

Ishii, Koji; Hasegawa, Hideki; Nagata, Noriyo; Ami, Yasushi; Fukushi, Shuetsu; Taguchi, Fumihiro; Tsunetsugu‐Yokota, Yasuko

We evaluated the efficacy of three SARS vaccine candidates in a murine SARS model utilizing low‐virulence Pp and SARS‐CoV coinfection. Vaccinated mice were protected from severe respiratory disease in parallel with a low virus titer in the lungs and a high neutralizing antibody titer in the plasma. Importantly, the administration of spike protein‐specific neutralizing monoclonal antibody protected mice from the disease, indicating that the neutralization is sufficient for protection. Moreover, a high level of IL‐6 and MCP‐1 production, but not other 18 cytokines tested, on days 2 and 3 after SARS‐CoV infection was closely linked to the virus replication and disease severity, suggesting the importance of these cytokines in the lung pathogenicity of SARS‐CoV infection.