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.