This study will investigate safety and reactogenicity of a monovalent conjugated vaccine against Haemophilus influenzae type b in healthy children

Inclusion Criteria:

• Infants of either sex, aged 16 - 20 months / 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;
• written informed consent 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 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;
• infants who have received any other Haemophilus influenzae type b immunization dose before (for 16-20 months old children who have received a booster vaccination already);
• 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) and/or 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;
• treatment with parenteral immunoglobulin preparation, blood products, and/or plasma derivatives (or: within the past 3 months - applicable for children 16 - 20 months);
• any vaccination administered within 2 weeks (14 days) before enrollment;
• 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