Safety and Immunogenicity of a Monovalent Conjugated Vaccine Against Haemophilus Influenzae Type b

Inclusion Criteria: * Infants of either sex, aged 2 - 4 months * In good health as determined by: * medical history * physical examination * clinical judgment of the investigator; * Available for all visits scheduled in the study and able to comply with all study regulations * For whom written informed consent has been obtained from at least one parent or legal guardian Exclusion Criteria: * Parent or legal guardian is unwilling or unable to give written informed consent to participate in study * Infants who have received any other Haemophilus influenzae type b immunization dose before * Infants who presented a previous disease potentially related to Haemophilus influenzae type b * Infants who had household contact and/or intimate exposure in the previous 30 days to an individual with ascertained Haemophilus influenzae type b disease * Premature (before 37th week of gestation) or birth weight less than 2500 g * History of anaphylactic shock, asthma, urticaria or other allergic reaction after previous vaccinations or hypersensitivity to any vaccine component * Fever ≥ 38.0 °C (axillary body temperature) or/and significant acute or chronic infection requiring systemic antibiotic or antiviral therapy within the past 7 days before enrollment * Subjects with any serious chronic disease such as cardiac, neurological, metabolic, hematologic, or neoplastic disease * Known/suspected immunodeficiency, or autoimmune disease, or any immunologic disorder * Subjects with any neurological disorder, e.g., epilepsy or history of seizure disorder * Subjects with a clinically significant genetic anomaly * Treatment with corticosteroids or other immunosuppressive drugs * Any previous treatment with parenteral immunoglobulin preparation, blood products, and/or plasma derivatives * Any vaccination administered within one week (7 days) before enrollment and/ or any planned administration of any vaccine outside the Chinese routine vaccination program. * Participation in any other investigational trial simultaneously * Planned surgery during the study period * Any condition, which, in the opinion of the investigator, might interfere with the evaluation of the study objective