The trial is a phase III, non-inferiority, observer-blind, randomised, active controlled, multicentre clinical trial with 2 parallel groups: IPV-Al SSI (investigational vaccine) and IPV SSI (comparator vaccine). The vaccines will be administered at 2, 4 and 6 months of age.

In addition to the trial vaccines (IPV-Al SSI or IPV SSI), the trial subjects will receive concomitant childhood vaccinations during the trial period. The trial vaccine (IPV-Al SSI or IPV SSI) is administered in the RIGHT thigh, whereas the other injectable childhood vaccines are administered in the opposite (LEFT) thigh.

At Visit 1 (inclusion, screening, blood sample, randomisation and 1st vaccination), written informed consent is obtained and the subject's eligibility is assessed according to the pre-specified in-/exclusion criteria. Information on medical history, demographics and concomitant medication are collected and a physical examination is performed and vital signs are measured. A prevaccination blood sample is taken for polio antibody determinations and the subject is randomly allocated into one of the two vaccination groups and vaccinated. A subset of 200 subjects are randomly chosen to have an extra blood sample taken at Visit 3. The subject is observed for immediate AEs 30 minutes after all vaccinations. An eDiary, thermometer and ruler are handed out to the parents for measurements of temperature and recording of injection site reactions and solicited systemic AEs. These activities are performed daily, starting on the day of the vaccination and the following 2 days and until resolved, and for recording of any other AEs as instructed by the trial staff. A contact to the parents via telephone will be made after the vaccination visit to remind the parents to fill in the eDiary and to check if they have any questions regarding how use the eDiary.

At Visit 2 (2nd vaccination), 2 months after Visit 1, the eDiary is collected and AEs and concomitant medications are recorded. Contraindications are reviewed, the 2nd vaccination is administered, immediate reactions are observed and the eDiary is returned to the partents for recordings of AEs and concomitant medications. A contact to the parents via telephone will be made after the vaccination visit to remind the parents to fill in the eDiary and to check if they have any questions regarding how use the eDiary.

At Visit 3 (3rd vaccination), 2 months after Visit 2, the eDiary is collected and AEs and concomitant medication are recorded. A blood sample from a subset of the subjects is taken for polio antibody determinations. Contraindications are reviewed, the 3rd vaccination is given, immediate reactions are observed and the eDiary is returned to the parents. A contact to the parents via telephone will be made after the vaccination visit to remind the parents to fill in the eDiary and to check if they have any questions regarding how use the eDiary.

At Visit 4 (blood sample and trial completion), 1 month after Visit 3, the eDiary is collected and AEs and concomitant medications are recorded and a blood sample for polio antibody determination is taken.

A safety follow-up telephone call will be conducted at 12 months of age.

Inclusion Criteria:

• Infants 2 months of age (54-75 days of age) on date of first vaccination
• Healthy assessed from medical history and physical examination
• Parent(s)/guardian(s) have been properly informed about the trial and signed informed consent form
• Parent(s)/guardian(s)granted access to the infant's trial related medical records
• Parent(s)/guardian(s)are likely to comply with trial procedures

Exclusion Criteria:

• Vaccinated with any polio vaccine other than the trial vaccines, prior to inclusion or planned during the trial
• OPV vaccination or known exposure to poliovirus (wild or vaccine-derived) in household (living together) within 3 months prior to inclusion or planned during the trial
• Low birth weight (< 2,500 g)
• Known or suspected immunodeficiency (e.g. leukaemia, lymphoma) or family history of congenital or hereditary immunodeficiency. HIV infection is not an exclusion criteria
• Severe uncontrolled chronic (e.g. neurologic, pulmonary, gastrointestinal, hepatic, renal or endocrine) disease
• Known or suspected allergy to vaccine constituents (e.g. hypersensitivity to formaldehyde, aluminium or 2-phenoxyethanol)
• Uncontrolled coagulopathy or blood disorder contraindicating intramuscular injections or blood sampling
• Treatment with a product which is likely to modify the immune response (e.g. systemic corticosteroids, blood products and immunoglobulins) prior to inclusion or planned during the trial period
• Participating in another clinical trial
• Not suitable for inclusion in the opinion of the investigator