Primary Outcome Measures:
- Occurrence of any RV GE caused by the circulating wild-type RV strains during the first efficacy follow-up period.
Secondary Outcome Measures:
- "Occurrence of severe RV GE caused by the circulating wild-type RV strains during the each efficacy follow-up period.
- Occurrence of any and severe RV GE caused by the circulating wild-type RV strains of G1 serotype during each efficacy follow-up period.
- Occurrence of any and severe RV GE caused by the circulating wild-type RV strains of non-G1 serotypes during each efficacy follow-up period.
- Occurrence of hospitalization due to RV GE caused by the circulating wild-type RV strains during each efficacy follow-up period.
- Occurrence of any medical attention (medical provider contact, advice, visit; emergency room contact or visit or hospitalization) for RV GE caused by the circulating wild-type RV strains during each efficacy follow-up period.
- Occurrence of any and severe RV GE caused by the circulating wild-type RV strains during the period starting from Dose 1 of the study vaccine until Visit 5.
- Occurrence of any and severe RV GE caused by the circulating wild-type RV strains during the first efficacy follow-up period in subjects who completed the two-dose vaccination course before the RV epidemic season.
- Occurrence of any and severe RV GE caused by the circulating wild-type RV strains during the first efficacy follow-up period in subjects who were vaccinated during the RV epidemic season.
- Immune response to HRV vaccine at Visit 1 and Visit 3.
- Immune response to all antigens contained in each of the different childhood vaccines at Visit 3 and Visit 4 or Visit 6 (if applicable):
- In a subset of subjects (N=1800), occurrence of each type of solicited symptom within the 8-day solicited follow-up period (Day 0 to Day 7) after each dose of HRV/placebo.
- For all subjects, occurrence of unsolicited symptoms within 31 days (Day 0 to Day 30) after each dose of HRV/placebo and SAEs throughout the entire study period.
The study has two groups: Group HRV and Group Placebo. Two oral doses administered to healthy infants who are 6-14 weeks of age at the time of Dose 1, according to a 0, 1 to 2-month schedule. Routine EPI vaccinations are given at the discretion of the investigator and according to local National Plans of Immunisation schedule in each participating country.