Progresses Toward Polio Eradication in Asian Countries: Its History and Japan's Contributions.

Japan experienced a large outbreak of wild poliovirus in the 1960s. The government made an exceptional decision to import oral polio vaccines (OPVs) from the Soviet Union and Canada while bypassing the usual approval process for medical products. Mass vaccination and subsequent, routine immunization successfully contained the wild poliovirus; the last case in Japan was reported in 1980. Domestic OPV had been used to sustain Japan's polio-free state. In 2012, the world's first inactivated polio vaccine developed from the Sabin vaccine replaced OPVs. Domestic vaccines combined with Sabin-derived inactivated polio vaccine are currently used in Japan. When the World Health Assembly announced the Global Polio Eradication Initiative in 1988, the Japanese government made a commitment to support endemic countries. The Japan International Cooperation Agency supported the establishment of microbiological laboratories, surveillance, distribution of polio vaccines and capacity building. Vaccine-derived poliovirus emerged as a new, international risk in the early 2000s. Vaccine-derived poliovirus was also detected in several Asian countries and required an outbreak response with additional vaccinations and strengthened surveillance. Genetically stable, novel, oral polio vaccine type 2 became available for use in outbreak responses and was used in Indonesia. Japan maintains its commitment to work toward the eradication of the poliovirus.