Assess the Immunogenicity of the Human Rotavirus (HRV) Vaccine After Reconstitution Without Buffering Agent; & Evaluate the Immunogenicity, Reactogenicity & Safety of the Vaccine After Storage for 7 d at 37°C Following 2 Doses in Healthy Infants

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 clinical examination before entering into the study. 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 (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs prior to the first vaccine dose, since birth. (For corticosteroids, this will mean prednisone, or equivalent, greater than or equal to 0.5 mg/kg/day. Inhaled and topical steroids are allowed.) * Planned administration of a vaccine (except routine paediatric vaccines) not foreseen by the study protocol. (If exceptionally OPV is given, this should be administered at least 14 days apart from the HRV vaccine or placebo dose.) * Any clinically significant history of chronic gastrointestinal 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 illness. * Gastroenteritis 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. * Previous confirmed occurrence of RV gastroenteritis.