A Study to Evaluate Immune Response and Safety of Two Doses of GSK Biologicals' HRV Liquid Vaccine in Healthy Infants.

Inclusion Criteria: * Healthy infants between, and including, 5-10 weeks of age at the time of the first dose of HRV liquid vaccine or placebo. * Birth weight of the subject should be \> 2000 grams. * Written informed consent obtained from the parent or guardian of the subject. Exclusion Criteria: * Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine within 30 days preceding the first dose of study vaccine, or planned use during the study period. * Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose. * Planned administration/ administration of a vaccine not foreseen by the study protocol except for DTPw, HBV and OPV vaccines within 14 days before each dose of HRV liquid vaccine or placebo and ending 14 days after. BCG is administered at birth according to the local EPI. * Concurrently participating in another clinical study, at any time during the study period. * Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required). * History of allergic disease or reactions likely to be exacerbated by any component of the HRV liquid vaccine or placebo. * Acute disease at the time of enrolment. * Administration of immunoglobulins and/or any blood products since birth or planned administration during the study period.