[Polio vaccines and biorisk management of polioviruses]

Japan is the first country where inactivated polio vaccines derived from Sabin attenuated strains, which are used to manufacture oral polio vaccines, were introduced in routine immunization program. The Sabin-derived inactivated vaccine has been developed based on the fact that Sabin strains are less neurovirulent and manufactured at safer productionfacilities than wild polioviruses. It is also convincing that Sabin strains are more safely used for evaluating the efficacy of inactivated vaccines in rat immunogenicity tests. However, in the current situation where polioviruses are close to being eradicated, the facilities that manufacture vaccines and/or conduct quality control of them are needed to meet the biorisk management requirements established by WHO, which are based on the Polio Eradication & Endgame Strategic Plan 2013-2018. At present, type 2 polioviruses including Sabin 2 strain should be contained in the facilities which meet the WHO biorisk management requirements. The respective facilities are expected to give full consideration based on a careful risk assessment of viral transmission not only to personnel, but also to the environment and the community around the facilities, and the establishment of biorisk management will be needed. Thus, the facilities handling and storing infectious polioviruses must be certified as poliovirus-essential facilities following the WHO biorisk management requirements.