MenACWY-CRM conjugate vaccine booster dose given 4-6 years after priming: Results from a phase IIIb, multicenter, open label study in adolescents and adults.

•A booster MenACWY-CRM dose was given 4–6 years post-MenACWY-CRM or -MenACWY-D priming.•The immune response to the booster was sufficient after priming with either vaccine.•A least 93.2% of primed participants had seroresponse for each vaccine serogroup at 28 days after the booster dose.•An anamnestic response was seen within 5 days after the booster dose.•The booster MenACWY-CRM dose had a clinically acceptable safety profile.