 Participants will receive a total of 5 doses of Hep B: One dose of Hep B monovalent vaccine given at birth or within 1 week after birth followed by 3 doses of the Sanofi Pasteurs hexavalent vaccine given at 2, 3, and 4 months of age Primary Series and then at 16 to 17 months of age booster to comply with Vietnamese vaccination recommendations. 