Study to Evaluate Eupolio(IPV)'s Safety, Long-term Protective Effect and Boosting Effect of One Booster Dose in the Three Primary Vaccination Plus Boosting Schedule, and Protective Effect in the Schedule With Bivalent OPV in Infants

Eupolio is inactivated poliovirus vaccine (IPV). Major purpose of this study is to evaluate safety of Eupolio in 2,000 infants. In addition to the safety, long-term protection after completion of the three primary vaccinations and extent of protective level after a single boosting dose of Eupolio will be evaluated. As IPV plus bOPV vaccination schedule (3 doses of bOPV plus 2 doses of IPV in infant-toddle vaccination schedule) has been implemented in some countries, this study will also evaluate Eupolio\'s safety and protective effect in that schedule.