A Study to Test 2 Doses of GSK Biologicals' Oral Live Attenuated Human Rotavirus (HRV) Vaccine in Healthy Infants

Inclusion criteria: * Healthy infants 6-12 or 11-17 weeks of age at the time of dose 1 whose parent/guardian sign a written informed consent and whose parents/guardians can and will comply with the requirements of the protocol. 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. * Chronic administration of immunosuppressants or other immune-modifying drugs since birth. * Child is unlikely to remain in the study area during study. * Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection. * History of allergic disease or reaction likely to be exacerbated by any component of the vaccine. * Administration of immunoglobulins and/or blood products since birth or planned administration during the study period. * Any clinically significant history of chronic gastrointestinal disease including any uncorrected congenital malformation of the gastrointestinal tract or other serious medical condition as determined by the investigator. * First or second degree of consanguinity of parents.