[Poliovirus vaccine].

To avoid the risk of vaccine-associated paralytic poliomyelitis (VAPP) and polio outbreaks due to circulating vaccine-derived polioviruses, an inactivated poliovirus vaccine (IPV) was introduced for routine immunization in a number of countries with a low risk of polio outbreaks. Currently, production and marketing of a standalone conventional IPV and two diphtheria-pertussis-tetanus-IPV (Sabin-derived IPV; sIPV) products have been submitted, and it is expected that the IPV products will be introduced in Japan in the autumn of 2012. At the same time, a decline in the OPV immunization rate became apparent in Japan due to serious public concerns about a remaining risk of VAPP and introduction of IPV in the near future. Therefore, the recent development of polio immunity gaps should be carefully monitored, and surveillance of suspected polio cases and laboratory diagnosis of polioviruses have to be intensified for the transition period from OPV to IPV in Japan. The development of sIPV is one of the most realistic options to introduce affordable IPV to developing countries. In this regard, further clinical studies on its efficacy, safety, and interchangeability of sIPV will be needed after the introduction of the sIPV products, which will be licensed in Japan for the first time in the world.