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.

Inclusion Criteria:

• Infants in stable health
• Male or female 6 to 8 weeks of age
• Signed informed consent by the infant's parent(s) or legally acceptable representative(s)

Exclusion Criteria:

• Known or suspected poliomyelitis
• Known or suspected febrile(symptom of a fever), or chronic illnesses
• Fever ≥ 38.0℃/100.4℉ within 3 days prior to study registration or intake of drug preventing fever
• Known or suspected immune disorders (abnormal activity in protective system in human body) or received immunosuppressive therapy (treatment for weaken protective system in human body)
• Previous use of blood or blood-derived products
• Previous use of polio vaccines
• Seizures (temporary abnormalities in muscle tone or movements due to abnormal activity in the brain)
• Bleeding disorders
• Household contact or intimate exposure with a confirmed case of polio
• Any history of allergy (hypersensitivity) to the components of the polio vaccine
• Participation in another interventional clinical trial simultaneously or within 30 days