Inactivation of Wild Poliovirus with β-Propiolactone

Antiviral vaccines are usually created by inactivating viruses using physical or chemical methods. Inactivation of poliovirus with β-propiolactone (BPL) has advantages, including the absence of a requirement for long-term incubation with the inactivating agent, which minimizes the risk of negative effects of the potentially dangerous substance on the virus and reduces the duration of the inactivation process.

BPL was applied at 0.2% (w/v) concentration under two conditions: 4 °C for 24 h and 37 °C for 3 h. Inactivation completeness was confirmed on Vero cell culture, while immunogenicity was assessed in guinea pigs via neutralizing antibody test.

Two variants of virus inactivation made it possible to obtain inactivated samples that retained their immunogenic properties. BPL-inactivated samples retained sufficient D-antigen levels and elicited neutralizing antibodies comparable to or exceeding those from formaldehyde-inactivated controls. The inactivation method at 37 °C provided faster inactivation, while at 4 °C it provided a smooth decrease in virus titer. These results confirm that β-propiolactone is a viable alternative to formaldehyde for the production of inactivated polio vaccine (IPV), providing rapid inactivation of the virus compared to inactivation with formaldehyde while maintaining immunogenicity, as confirmed by guinea pig control.