Meningococcal serogroup B vaccine (4CMenB): Booster dose in previously vaccinated infants and primary vaccination in toddlers and two-year-old children.

OBJECTIVE

The multicomponent, recombinant serogroup B vaccine, 4CMenB, is approved in Europe, Canada and Australia from two months of age. We investigated persistence to booster doses at 12 months of age following infant vaccination, and immune response to catch-up vaccination of toddlers and children up to two years of age.

METHODS

We assessed persistence of immune responses after one year in participants vaccinated as infants, and responses to two doses at 12-15 or 24-26 months of age in vaccine-naïve children, as serum bactericidal activity with human complement (hSBA) against indicator strains for four vaccine antigens. Adverse events were recorded after each vaccination.

RESULTS

High antibody titers were induced against all four 4CMenB components following booster vaccination in infant-primed toddlers and after two doses in previously unvaccinated toddlers or two-year-olds. Antibodies waned over 12 months, particularly those against NZ OMV. Systemic reactogenicity in toddlers was lower than in infants, and lower again in vaccine-naïve two-year-olds. Local reactogenicity was common in all groups.

CONCLUSIONS

Four infant or two toddler 4CMenB vaccinations elicit immune responses believed to be protective for the first two years of life, which can be boosted. Reactogenicity is lower in toddlers than in infants.