Rotavirus (RV) is the most important cause of acute gastroenteritis (GE) requiring the hospitalization of infants and young children in developed and developing countries and can be a frequent cause of death in children less than 5 years of age (estimated nearly 500,000 annual deaths worldwide). GlaxoSmithKline (GSK) Biologicals has developed a vaccine against human rotavirus gastroenteritis. This study will provide data for Korean regulatory authorities about the immunogenicity and safety of this vaccine in Korean children aged 2 months at the time of the first dose.

The study consists of two groups of children recruited in different centers in Korea. One group will receive the HRV vaccine and one group will receive the placebo. The vaccine or placebo will be administered starting at 2 months of age according to a two dose schedule (0, 2 months). The study will consist of three visits. At the first visit, one blood sample will be taken before vaccination and the first dose will be administered. At the second visit (2 months after first dose), the second vaccine will be administered. At the third visit (2 months after second dose), a blood sample will be taken. A 15-day (Day 0 - 14) follow-up period will be observed for general symptoms solicited in the study (fever, fussiness/irritability, diarrhea, vomiting, loss of appetite and cough/runny nose). A 43-day (Day 0 - 42) follow-up will be observed for other unsolicited symptoms. Serious adverse events will be followed-up throughout the study. A stool sample should be collected from the child at any point during the study if he/she develops any GE.

Inclusion Criteria:

• A male or female between, and including, 6 and 12 weeks (42-90 days) of age at the time of the first vaccination.
• Written informed consent obtained from the parent or guardian of the subject.
• Free of obvious health problems, as established by medical history and physical examination, before entering into the study.
• Subjects for whom the vaccination history is available from vaccination diary cards or medical charts or patient diary cards.

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 placebo, or planned use during the study period.
• Planned administration of a vaccine (including routine paediatric vaccines) not foreseen by the study protocol during the period starting from 14 days before each dose of study vaccine(s) and ending 14 days after.
• Any clinically significant history of chronic gastrointestinal (GI) disease including any uncorrected congenital malformation of the GI tract or other serious medical condition, as determined by the investigator.
• History of allergic disease or reactions likely to be exacerbated by any component of the vaccine.
• Any confirmed or suspected immunosuppressive or immunodeficient condition based on medical history and physical examination (no laboratory testing is required).
• Major congenital defects or serious chronic illnesses such as malignant disease (e.g. melanotic neuroectodermal tumor, malignant rhabdoid tumor, etc.), serious atopic dermatitis, conditions that are the result of premature birth, etc.
• Acute disease at time of enrolment. (Acute disease is defined as the presence of moderate or severe illness with or without fever i.e. temperature >= 37.5°C as measured by an axillary thermometer or >= 38.0°C as measured by a rectal thermometer. A temperature greater than or equal to these cut-offs warrants deferral of the vaccination pending recovery of the subject.)
• GE within 7 days preceding the study vaccine administration (warrants deferral of the vaccination).
• Administration of immunoglobulins and/or blood products since birth or planned administration during the study period. Oral intake of immunoglobulins via, e.g., breastfeeding is allowed.
• Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs since birth. (For corticosteroids, this will mean prednisone, or equivalent, >= 0.5 mg/kg/day. Inhaled and topical steroids are allowed.)
• Previous confirmed occurrence of RV GE.
• Household contact with an immunosuppressed individual

Patient-level data for this study will be made available through www.clinicalstudydatarequest.com following the timelines and process described on this site.