Study of a Tetravalent Meningococcal Diphtheria Toxoid Conjugate Vaccine in Toddlers 9 to 18 Months of Age

This is a Phase II, open-label, parallel, exploratory, multi-center study in healthy toddlers.

Inclusion criteria

• Aged either 9, 12, 15 or 18 months of age or 3 to < 6 years of age on the day of inclusion.
• Informed consent form that has been approved by the site's Institutional Review Board (IRB) and signed by the parent or legal guardian
• Able to attend all scheduled visits and to comply with all trial procedures

Exclusion criteria

• History of a serious chronic disease that could interfere with trial conduct or completion.
• Known or suspected impairment of immunologic function.
• Acute medical illness with or without fever within the last 72 hours, or rectal temperature ≥ 100.4°F (≥ 38.0°C) or axillary temperature ≥ 99.4°F (≥ 37.4°C) on the day of inclusion.
• History of invasive meningococcal disease (confirmed either clinically, serologically or microbiologically) or previous meningococcal vaccination.
• Administration of immune globulin or other blood products within 3 months, or oral or parenteral corticosteroids or other immunosuppressive therapy within the last 6 weeks of the study vaccine. Individuals on a tapering dose schedule of oral steroids lasting < 7 days may be included in the trial as long as they have not received more than one course within the last two weeks prior to enrollment.
• Antibiotic therapy within the 72 hours prior to having any blood sample drawn.
• Received or scheduled to receive any vaccine in the 28-day period prior to receipt of either dose of the study vaccine, or scheduled to receive any vaccination other than influenza vaccination and hyposensitization therapy in the 28-day period after receipt of either dose of the study vaccine. Hyposensitization therapy and influenza vaccination may be received up to two weeks before or after receiving the trial vaccine.
• Suspected or known hypersensitivity to any of the vaccine components or history of a life-threatening reaction to the trial vaccine or a vaccine containing the same substances.
• Thrombocytopenia or a bleeding disorder contraindicating intramuscular vaccination
• Unable to attend one or more of the scheduled visits or to comply with the study procedures.
• Participation in another clinical trial in the 4 weeks preceding enrollment.
• Planned participation in another clinical trial during the present trial period.
• Any condition which, in the opinion of the investigator, would pose a health risk to the subject or interfere with the evaluation of the vaccine.