Hong Kong Med J 2008;14(Suppl 4):S39-43
Studies of SARS virus vaccines
BJ Zheng, LY Du, GY Zhao, YP Lin, HY Sui, C Chan, S Ma, Y Guan, KY Yuen
1. Intranasal vaccination using inactivated SARS coronavirus (SARS-CoV) vaccine with adjuvant can induce strong systemic (serum immunoglobulin [Ig] G) and respiratory tract local (tracheal-lung wash fluid IgA) antibody responses with neutralising activity.
2. RBD-Fc (protein-based vaccine) is able to induce effective neutralising antibodies able to provide protection from SARS-CoV infection in animal models.
3. A single dose of RBD-rAAV vaccination can induce adequate neutralising antibody against SARS-CoV infection.
4. Additional doses of vaccine increased the production of neutralising antibody 5-fold compared with a single dose.
5. RBD-rAAV vaccination provoked a prolonged antibody response with continually increasing levels of neutralising activity.
6. Intranasal vaccination with RBD-rAAV induced local IgA and systemic IgG neutralising antibodies and specific T-cell responses, able to protect against SARS-CoV infection in animal models.
7. When compared with the RBD-rAAV prime/boost vaccination, RBD-rAAV prime/RBD-peptide boost induced similar levels of Th1 and neutralising antibody responses that protected vaccinated mice from subsequent SARS-CoV challenges,but stronger Th2 and CTL responses.
8. Overall, our findings suggest that the inactivated vaccine, RBD-Fc and RBD-rAAV, can be further developed into effective and safe vaccines against SARS and that intranasal vaccination may be the preferred route of administration.