Inclusion Criteria:
Subjects who the investigator believes that parent(s)/Legally Acceptable Representative(s) [LAR(s)] can and will comply with the requirements of the protocol.
A male or female 1 to 17 years of age at the time of the first vaccination.
Written informed consent obtained from the parent(s)/LAR(s) of the subject and informed assent obtained from the subject, if appropriate, prior to enrolment.
Female subjects of non-childbearing potential may be enrolled in the study.
Female subjects of childbearing potential may be enrolled in the study, if
- the subject has practiced adequate contraception for one month (30 days) prior to the first vaccine dose, and
- has a negative pregnancy test on the day of vaccination, and
- has agreed to continue adequate contraception from administration of the first vaccine dose until 2 months after administration of the second vaccine dose.
Additional inclusion criterion for At-risk group • Subjects with an increased risk for meningococcal disease, such as anatomic asplenia or some degree of functional asplenia or complement deficiencies.
Additional inclusion criteria for Healthy group
- Healthy subject as established by medical history and clinical examination before entering into the study.
- Age-matched to a subject from the At-risk group according to age strata 1-5 years, 6-10 years and 11 to 17 years.
Exclusion Criteria:
- Child in care.
- Use of any investigational or non-registered product other than the study vaccine within 30 days preceding the first dose of study vaccine, or planned use during the study period (until the phone contact at Month 8).
- Planned administration/administration of a vaccine not foreseen by the study protocol during the period starting 30 days before administration of each study vaccine dose until 30 days after administration of each study vaccine dose. Administration of licensed inactivated influenza vaccines is allowed as per local recommendations.
- Concurrently participating in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational product.
- History of meningococcal disease.
- Any confirmed or suspected Human Immunodeficiency Virus (HIV) infection, based on medical history and physical examination.
- Administration of immunoglobulins and/or any blood products within the 3 months preceding the first dose of study vaccine until one month after the second dose of study vaccine.
- History of any reaction or hypersensitivity likely to be exacerbated by any component of the vaccine including latex.
- Major congenital defects.
- History of any neurological disorders or seizures, including Guillain-Barré syndrome (GBS). History of a simple, single febrile seizure is permitted.
- Acute disease and/or fever at the time of enrolment.
- Pregnant or lactating female.
- History of chronic alcohol consumption and/or drug abuse.
- Female planning to become pregnant or planning to discontinue contraceptive precautions.
Additional exclusion criteria for the At-risk group
• Vaccination against meningococcal disease of any serogroup
- within the last 3 years for subjects younger than 7 years.
- within the last 5 years for subjects 7 years and older.
Additional exclusion criteria for the Healthy group
- Vaccination against meningococcal disease of any serogroup with polysaccharide or conjugate vaccine within the last 5 years.
- Chronic administration of immunosuppressants or other immune-modifying drugs within 6 months prior to the first vaccine dose.
- Family history of congenital or hereditary immunodeficiency.
- Any confirmed or suspected immunosuppressive or immunodeficient condition.
- Serious chronic illness.
- History of asplenia or hyposplenia or complement deficiencies.