3 Adjuvated Reduced Dose IPV-Al SSI and Non-adjuvated Full Dose IPV SSI Given as Primary Vaccinations to Infants

The trial is a phase II, dose investigation, parallel and multi-group, observer-blind, randomised, controlled, multicentre and non-inferiority trial.

Three investigational reduced dose adjuvated IPV-Al SSI vaccines and full dose IPV SSI vaccine will be investigated in four parallel groups:

• 1/3 IPV-Al SSI
• 1/5 IPV-Al SSI
• 1/10 IPV-Al SSI
• IPV Vaccine SSI (comparator)

At Visit 1 (screening and 1st vaccination visit), written informed consent is obtained and the subject's eligibility is assessed according to the pre-specified in-/exclusion criteria, including measurement of axillary temperature. If the subject is included, a pre-vaccination blood sample is taken for polio antibody determinations, and the subject is randomly allocated into one of the four groups to be vaccinated.

The subject is observed for ½ an hour after the injection of the investigational medical product (IMP) and any immediate adverse events observed are to be recorded. A diary, thermometer and ruler are handed out to the parents/guardians so that they can measure daily the injection site reactions and the axillary temperature the first 3 days and record any adverse event until the next visit.

At Visit 2 (2nd vaccination visit), 28-42 days after Visit 1, contraindications are reviewed, the 2nd vaccination is given, the diary is collected and adverse events and concomitant medications are recorded in the eCRF. A new diary is handed out.

At Visit 3 (3rd vaccination and blood sample visit), 28-42 days after Visit 2, a blood sample for immunogenicity assessment is taken, contraindications are reviewed, the 3rd vaccination is given, the diary is collected and adverse events and concomitant medications are recorded in the eCRF. A new diary is handed out.

At Visit 4 (blood sample visit), 28-42 days after Visit 3, a blood sample for immunogenicity assessment is taken, the diary is collected, and adverse events and concomitant medications are recorded in the eCRF. The trial termination form is completed.

Inclusion criteria

• Infants of 6 weeks of age (+7 days) on date of first vaccination
• Healthy assessed from medical history and physical examination
• One parent/guardian has been properly informed about the trial and has signed the informed consent form
• One parent/guardian grants access to the infant's trial related medical records
• One parent/guardian is likely to comply with trial procedures

Exclusion criteria

• Vaccinated with poliovirus vaccine (OPV or IPV), other than the trial vaccines, prior to inclusion or planned during the trial (e.g. on national polio immunisation days)
• OPV vaccination or known exposure to poliovirus in household (living together) within 3 month prior to inclusion or planned during the trial
• Has a sibling who is ≤5 years of age, and for whom OPV vaccination is planned during the trial
• Low birth weight (< 2,500 g)
• Known or suspected immunodeficiency (e.g. HIV, leukaemia, lymphoma) or family history of congenital or hereditary immunodeficiency
• Severe uncontrolled chronic disease (e.g. neurologic, pulmonary, gastrointestinal, hepatic, renal or endocrine)
• Known or suspected allergy to vaccine constituents (e.g. hypersensitivity to formaldehyde)
• Acute severe febrile illness at day of vaccination deemed by the investigator to be a contraindication for vaccination
• 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. blood products and immunoglobulins) prior to inclusion or planned during the trial
• Participating in another clinical trial
• Not suitable for inclusion in the opinion of the investigator