immunogenicity and safety of sanofi pasteur's combined vaccine given as a three-dose primary series at 2, 3,4 months of age and followed by a booster dose given at 16 to 17 months of age in vietnamese infants who previously received a dose of hepatitis b vaccine at birth or within 1 week after birth

Conditions: Diphtheria; Tetanus; Pertussis; Poliomyelitis; Hepatitis B; Haemophilus Influenzae Type b

Summary: the purpose of this study is to describe the immunogenicity and safety of sanofi pasteur's dtap-ipv-hep b-prp-t fully liquid combined hexavalent vaccine (hexaxim®) administered at 2, 3, and 4 months of age and at 16 to 17 months of age in infants and toddlers who received a dose of hep b vaccine at birth or within 1 week after birth. primary objective: * to describe the safety profile after each and all doses of sanofi-pasteur's dtap-ipv-hep b-prp-t combined vaccine in vietnamese infants and toddlers. secondary objective: * to demonstrate the non-inferiority of the immune response to all antigens induced by the study vaccine in vietnamese infants one month after the third dose in a 3-dose primary series with the immune response to all antigens induced by the same study vaccine outside vietnam. * to evaluate the immunogenicity of the study vaccine one month after the 3-dose primary series. * to describe the persistence of all antibodies before receipt of the booster vaccination. * to evaluate the immunogenicity of the study vaccine one month after the booster.

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 pasteur's hexavalent vaccine given as primary series at 2, 3, and 4 months of age and then a booster dose at 16 to 17 months of age, to comply with vietnamese vaccination recommendations.

Eligibility criteria:
inclusion criteria: * aged 61 to 91 days on the day of the first study visit * born at full term of pregnancy (≥ 37 weeks) and with a birth weight ≥2.5 kg * informed consent form has been signed and dated by the parent(s) or other legally acceptable representative (and by an independent witness if required by local regulations) * subject and parent/legally acceptable representative are able to attend all scheduled visits and to comply with all trial procedures * have received one dose of hep b vaccine at birth or within 1 week after birth (documented according to the national recommendations). exclusion criteria: * participation in the 4 weeks preceding the first trial vaccination or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure * receipt of any vaccine in the 4 weeks preceding the first trial vaccination or planned receipt of any other vaccine within the period from 8 days before to 8 days after each subsequent trial vaccination except for bacille calmette guerin (bcg) vaccination (any administration of oral poliovirus vaccine (opv) in the context of oral poliovirus vaccine-national immunization days (nids) does not fall within the scope of this exclusion criterion) * previous vaccination against diphtheria, tetanus, pertussis, poliomyelitis, hepatitis b (except the dose of hep b vaccine given at birth or within 1 week after birth) diseases or haemophilus influenzae type b infection with either the trial vaccine or another vaccine (any administration of opv in the context of opv-nids does not fall within the scope of this exclusion criterion) * past or current receipt of immune globulins, blood or blood-derived products or planned administration during the trial * known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy since birth; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks since birth) * history of diphtheria, tetanus, pertussis, poliomyelitis, hepatitis b, or haemophilus influenzae type b infections (confirmed either clinically, serologically or microbiologically) * known personal or maternal history of human immunodeficiency virus (hiv), or hepatitis c seropositivity * known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccine used in the trial or to a vaccine containing any of the same substances * known thrombocytopenia, as reported by the parent/legally acceptable representative * bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular vaccination * history of seizures * in an emergency setting, or hospitalized involuntarily * chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion * moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (temperature ≥38.0°c). a prospective subject should not be included in the study until the condition has resolved or the febrile event has subsided * identified as a natural or adopted child of the investigator, relatives or employee with direct involvement in the proposed study.

Keywords: diphtheria tetanus pertussis poliomyelitis hepatitis b haemophilus influenzae type b dtap-ipv-hep b-prp-t combined vaccine (hexaxim®)