The Final Stage of Developing Genetically Modified Inactivated Sabin Vaccine for the Eradication of Poliovirus

The polio vaccine is one of the most successful vaccines which have reduced worldwide poliomyelitis caused by poliovirus infection. The poliovirus is a human enterovirus which belongs to the Picornaviridae family. Formalin- Inactivated Poliovirus Vaccine (IPV) developed by Salk was the first poliovirus vaccine to be licensed in 1955. The IPV was the only poliovirus vaccine available until licensure of the Oral Poliovirus Vaccine (OPV) in1963. The OPV is a live attenuated vaccine that has long-lasting immune response but requires several boosters, is safe and effective. Elimination of poliomyelitis in the developing world was achieved mainly through mass vaccination with the OPV despite its ability to revert to the wild type. However, polio still persistently remained endemic in Afghanistan and Pakistan. One of the most anticipated next generation vaccines is an IPV based on the attenuated Sabin poliovirus strains. An attenuated Sabin IPV (sIPV) has been used in Japan for the past 3 years in their routine immunization program and licensed in China to be introduced in routine immunization in several provinces. The sIPV is produced from poliovirus strains that have an antigenic structure identical to the currently used wild-type strains but were rendered non-pathogenic by genetic manipulations.