Immunogenicity of a single 4CMenB vaccine booster in adolescents 11 years after childhood immunisation

•Two doses of 4CMenB are required in naïve adolescents to elicit sufficient bactericidal activity.•Impact of childhood vaccination with 4CMenB on response to a single boost at adolescence is unknown.•No safety concerns raised after administration of fourth to sixth doses of 4CMenB in adolescence.•A single dose induced better responses in previously vaccinated than in naïve adolescents.•Responses to the adolescent dose were better when a preschool boost had been administered.