• "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 main objectives of this study is to determine vaccine efficacy against any rotavirus (RV) gastroenteritis (GE) during the first efficacy 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.

Inclusion criteria:

• Healthy infants 6 -14 weeks of age at the time of the first study vaccination with birth weight > 2000g whose parent/guardian sign a written informed consent and whose parents/guardians can and will comply with the requirements of the protocol (e.g., completion of the diary cards, return for follow-up visits).

Exclusion criteria:

• Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine(s) within 30 days preceding the first dose of study vaccine, or planned use during the study period.
• Planned administration of a vaccine not foreseen by the study protocol within 14 days before each dose of study vaccine(s) and ending 14 days after.
• Chronic administration (defined as more than 14 days) of immunosuppressants since birth. (Topical steroids are allowed.)
• History of diphtheria, tetanus, pertussis, Hib disease and/ or hepatitis B disease (in all subjects). Only for subjects in Spain: history of meningococcal group C disease. Only for subjects in France and Germany: history of disease caused by Streptococcus pneumoniae.
• History of use of experimental rotavirus vaccine.
• Previous vaccination against diphtheria, tetanus, pertussis, Haemophilus influenzae type b (in all subjects). Only for subjects in Spain: previous vaccination against meningococcal group C. Only for subjects in France and Germany: previous vaccination against Streptococcus pneumoniae.
• Any clinically significant history of chronic gastrointestinal disease including any uncorrected congenital malformation of the GI tract, IS or other medical condition determined to be serious by the investigator.
• Any confirmed or suspected immunosuppressive or immunodeficient condition based on medical history and physical examination (no laboratory testing is required).
• History of allergic disease or reaction likely to be exacerbated by any component of the vaccine.
• Acute disease at the time of enrolment. (Acute disease is defined as the presence of a moderate or severe illness with or without fever. All vaccines can be administered to persons with a minor illness such as mild upper respiratory infection with or without low-grade febrile illness, i.e. Oral temperature <37.5°C (99.5°F) / Axillary temperature <37.5°C (99.5°F) / Rectal temperature <38°C (100.4°F).)
• Gastroenteritis within 7 days preceding the first study vaccine administration (warrants deferral of the vaccination).
• A family history of congenital or hereditary immunodeficiency.
• Administration of immunoglobulins and/or blood products since birth or planned administration during the study period.
• History of any neurologic disorders or seizures.
• Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination or laboratory screening tests.