Persistence of immunity after vaccination with a capsular group B meningococcal vaccine in 3 different toddler schedules [Research]

BACKGROUND:

One schedule for the capsular group B meningococcal vaccine 4CMenB is 2 doses that are administered 2 months apart for children aged 12–23 months, with a booster dose 12–24 months later. Our objective was to provide data on persistence of human serum bactericidal antibody (hSBA) titres in children up to 4 years of age after initial doses at 12–24 months, and immunogenicity of a booster dose at 48 months of age compared with vaccine-naive children.

METHODS:

Children previously immunized, as part of a randomized controlled trial, with 2 doses of 4CMenB vaccine at 12–24 months of age received a booster at 4 years of age. Vaccine-naive age-matched toddlers received 2 doses of 4CMenB. Human serum bactericidal antibody titres against reference strains H44/76, 5/99, NZ98/254 and M10713 were evaluated before and after innoculation with 4CMenB vaccine in 4-year-old children.

RESULTS:

Of 332 children in the study, 123 had previously received 4CMenB and 209 were vaccine-naive controls. Before the booster, the proportions of participants (previously vaccinated groups compared with controls) with hSBA titres of 1:5 or more were as follows: 9%–11% v. 1% (H44/76), 84%–100% v. 4% (5/99), 0%–18% v. 0% (NZ98/254) and 59%–60% v. 60% (M10713). After 1 dose of 4CMenB in previously immunized children, the proportions of participants achieving hSBA titres of 1:5 or more were 100% (H44/76 and 5/99), 70%–100% (NZ98/254) and 90%–100% (M10713).

INTERPRETATION:

We found that waning of hSBA titres by 4 years of age occurred after 2 doses of 4CMenB vaccine administered at 12–24 months, and doses at 12–24 months have a priming effect on the immune system. A booster may be necessary to maintain hSBA titres of 1:5 or more among those children with increased disease risk. Trial registration: ClinicalTrials.gov, no. NCT01717638

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