Antibody persistence and booster responses 24-36 months after different 4CMenB vaccination schedules in infants and children: A randomised trial.

OBJECTIVES

This phase IIIb, open-label, multicentre, extension study (NCT01894919) evaluated long-term antibody persistence and booster responses in participants who received a reduced 2 + 1 or licensed 3 + 1 meningococcal serogroup B vaccine (4CMenB)-schedule (infants), or 2-dose catch-up schedule (2-10-year-olds) in parent study NCT01339923.

MATERIALS AND

METHODS

Children aged 35 months to 12 years (N = 851) were enrolled. Follow-on participants (N = 646) were randomised 2:1 to vaccination and non-vaccination subsets; vaccination subsets received an additional 4CMenB dose. Newly enrolled vaccine-naïve participants (N = 205) received 2 catch-up doses, 1 month apart (accelerated schedule). Antibody levels were determined using human serum bactericidal assay (hSBA) against MenB indicator strains for fHbp, NadA, PorA and NHBA. Safety was also evaluated.

RESULTS

Antibody levels declined across follow-on groups at 24-36 months versus 1 month post-vaccination. Antibody persistence and booster responses were similar between infants receiving the reduced or licensed 4CMenB-schedule. An additional dose in follow-on participants induced higher hSBA titres than a first dose in vaccine-naïve children. Two catch-up doses in vaccine-naïve participants induced robust antibody responses. No safety concerns were identified.

CONCLUSION

Antibody persistence, booster responses, and safety profiles were similar with either 2 + 1 or 3 + 1 vaccination schedules. The accelerated schedule in vaccine-naïve children induced robust antibody responses.