Long-term seroprotection after an adolescent booster meningococcal serogroup C vaccination

Abstract

Registered on ClinicalTrials.gov (NCT01459432).

Meningococcal C conjugate age-dependant long-term loss of effectiveness

“…Seroprevalence studies developed in different countries showed a decline in effectiveness in infants parallel to a decline in serum bactericidal antibody titres (SBA), while in adolescents, effectiveness and SBA titres remained more stable in time [9,[13][14][15][16][17][18]. Moreover, SBA titres increased gradually with age between 6 and 18 years of age, in which a single dose of vaccine resulted in persistently high and bactericidal antibody levels up to at least five years after vaccination [16][17][18].…”

Clinical and Epidemiological Differences Among Meningococcal C Conjugate Vaccine Failures and Non-Vaccinated Cases

“…Nevertheless, this is derived from the low proportion of vaccine failures among those vaccinated and we still consider relevant this study to identify information gaps for future in deep research; fifth, we do not have information about the type of vaccine failure. However, waning of the protective antibodies have been sufficiently described [9,[12][13][14][15][16]39,40] and most of the cases of meningococcal disease are related to secondary vaccine failures. Moreover, in our previous study we observed an accumulation of vaccine failures ≥ 2 years since vaccination while vaccine effectiveness at 0-1 years since vaccination was near to 100% [18].…”

“…Loss of vaccine effectiveness and the apparition of vaccine failures have been associated to an inadequate maintenance of circulating antibodies [7][8][9]. The effect of immaturity of the immune system in infants [10,11] to maintain the antibody levels in time has been widely studied in seroprevalence studies [9,[12][13][14][15][16][17]. In line with this, in our previous nationwide study evaluating vaccine effectiveness after 13 years since the conjugate vaccine introduction, we found 63.97% of vaccine failures in those vaccinated before the year of age (2-3 doses), 32.08% in those vaccinated between 1 and 11 years (1 dose) and 3.88% in those vaccinated between 12-19 years (1 dose) [18].…”

Is a single infant priming dose of meningococcal serogroup C conjugate vaccine in the United Kingdom sufficient?

“…A booster dose of MCC in early adolescence should maintain high levels of bactericidal antibodies throughout adolescence and early adulthood. 22 The meningococcal serogroup B vaccine, Bexsero Ò received licensure in Europe in 2013 23 and has been recommended by the UK JCVI for inclusion into the infant immunisation program. 24 Bexsero Ò has the potential to provide some protection to other serogroups of meningococci, (due to fact that the vaccine antigens are subcapsular proteins) including serogroup C and that infant MCC offered at 3 months of age could potentially be removed from the schedule.…”

“…In 2013, the UK introduced an adolescent booster (at age 13-14 years) of a MCC vaccine, in order to keep the young adults protected when subjects who were vaccinated at an early age reach adulthood. 21,22 At the same time, a booster dose of MCC vaccine was recommended to first time university entrants under the age of 25 years, for a limited time to offer protection to those who would not have received an adolescent booster. It is expected that if this adolescent booster was not introduced, protection in adolescents will wane dramatically resulting in a new peak in MenC disease not only in this age group but in infants and young children if MenC circulation increases.…”