To establish the production process of inactivated poliovirus vaccine (IPV) derived from Sabin strain and evaluate the immunogenicity of Sabin strain IPV (sIPV).

TypesⅠ, Ⅱ, and Ⅲ Sabin strain polioviruses were cultured in Vero cells to prepare trivalent sIPV. D antigen contents of sIPV were quantified by ELISA.Virus titers were tested. Virus was identified by electron microscope and electrophoresis. Antigen purity was tested. Host cell DNA and protein contents were determined. Immunogenicity of sIPV was compared with wild type IPV by potency test in rats. Dynamic changes of neutralizing antibody titer were observed.

D antigen contents of typesⅠ, Ⅱ, and Ⅲ polioviruses were 2 437, 365, and 1 253 DU/ml, and average virus titers were 8.4, 7.8, and 7.9 lg 50% cell culture infectious dose per ml, respectively. The purity of purified virus fluid was >99%. By electron microscopy, 20-30 nm diameter virus particles were observed and confirmed by electrophoresis.Residual DNA content and host cell protein content of purified virus fluid were 12.3 pg/500 μl and 9.8 ng/ml, respectively. The geometric mean titers (GMTs) of neutralizing antibodies against types Ⅰ, Ⅱ, and Ⅲ induced by 3 injections of sIPV were 9 397.8, 554.7, and 4 668.4, respectively, significantly higher than that of wild type IPV for type Ⅰ ( t=-3.429, P=0.004), and no significant difference for type Ⅱ and type Ⅲ. The neutralizing antibody GMTs kept at a higher level within 19 weeks after primary immunization.

A stable production process of sIPV is developed and the vaccine products have good immunogenicity.

Poliovirus vaccine, inactivated; Immunogenicity; Preparation