Adolescent MenACWY Booster Study

Participants will be randomized to receive one of the three doses of licensed MenACWY as a booster dose in adolescents. Serology will be collect at 3 time points; prior to the booster dose and 1 month and 1 year post-vaccination to measure antibody levels. The participants are healthy students in grades 7-9 who have not received their MenACWY vaccine yet and received their routine infant MenC vaccines per previous Canadian schedules.

Inclusion criteria

All the following need to be fulfilled:

• Healthy adolescent
• Previous receipt of appropriate MenC vaccine according to the relevant provincial schedule (see above)
• Parent/legal guardian has given informed consent OR participant has given consent (if participant demonstrates capacity to consent)
• Participant has given consent (as above) OR assent.

Exclusion criteria

The participant may not enter the trial if ANY of the following apply:

• Has already received any doses of MenACWY vaccine at any age
• Previous confirmed or suspected meningococcal disease
• Close contact with an individual with laboratory-confirmed N. meningitidis in prior 12 months
• Previous allergic reaction to a component of any of the 3 vaccines
• Serious chronic or progressive disease
• Confirmed/suspected immunodeficiency
• Receipt of more than 1 week of immunosuppressants or immune modifying drugs (e.g. oral prednisolone >0.5mL/kg/day or intravenous glucocorticoid steroid). Nasal, topical or inhaled steroids are allowed
• Administration of immunoglobulins within the prior 12 months and/or any blood products planned during the study period
• Pregnancy (based on history from adolescent and parent/legal guardian)
• Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial.

TEMPORARY EXCLUSION CRITERIA If the adolescent has a temperature ≥ 38°C, then vaccination (and blood sampling if due to occur at same visit) will be postponed until resolution of fever.