Apart from 1 case in an individual (62?years old) vaccinated on the same day of the symptom onset, in the remaining 4 cases (9C22?years old), the vaccine was administered 2C10?years before the symptom onset

Apart from 1 case in an individual (62?years old) vaccinated on the same day of the symptom onset, in the remaining 4 cases (9C22?years old), the vaccine was administered 2C10?years before the symptom onset. booster dose against 5 meningococcal C (MenC) strains isolated from IMD cases. Sera collected from 90 infants/toddlers who participated in a phase AS2717638 III, open-label study (NCT00667602) and its extension (NCT01345721) were tested by serum bactericidal activity assay with human complement (hSBA). Children were primed with either MenACWY-CRM at 6C8 and 12?months of age (group 2_MenACWY; N =?30), MenACWY-CRM (group 1_MenACWY; N =?30), or MenC-CRM at 12?months of age (group 1_MenC; N =?30); all received MenACWY-CRM booster dose at 22C45?months of age. Four tested strains (FI001CFI004) were C:P1.5C1,10-8:F3-6:ST-11 (cc11) and 1 (FI005) was C:P1.7C4,14-6:F3-9:ST-1031 (cc334). Overall, immune responses tended to be higher against Fl002CFI004 than Fl001 and Fl005. Geometric imply titers were high in group 2_MenACWY (range: 94.8 [FI005]C588.1 [FI004]) and very high post-boosting with MenACWY-CRM in all groups Rabbit Polyclonal to BUB1 (176.9 [FI005]C3911.0 [FI004]). Seroresponse rates tended to be higher in group 1_MenC (33.3% [FI005]C93.3% [FI004]) than in group 1_MenACWY (16.7% [FI005]C73.3% [FI004]). Irrespective of strains tested or the identity/number of priming doses, 96.7% of children experienced hSBA titers 1:8 post-MenACWY-CRM booster dose. MenACWY-CRM and MenC-CRM elicited bactericidal antibodies and immunological memory against hypervirulent cc11 and cc334 MenC strains responsible for IMD outbreaks. KEYWORDS: Hypervirulent MenC AS2717638 strains, cc11/cc334 clonal complexes, outbreak, MenACWY-CRM conjugate vaccine, MenC-CRM conjugate vaccine Introduction An increase of serogroup C (MenC) invasive meningococcal disease (IMD) was reported during January 2015CFebruary 2016 in Tuscany, a region located in the center of Italy.1 Within this period of slightly more than 1 12 months, 43 confirmed MenC IMD cases, of which 10 fatal, were reported, accounting for approximately 38% of all confirmed MenC IMD cases recorded since 2000 in the region (overall, 111 MenC IMD cases from January 2000 to February 2016). The vast majority (87.5%) of MenC strains isolated during this outbreak belonged to the clonal complex (cc) 11, with cc334 isolated in fewer individuals.1 This analysis aimed to evaluate the magnitude of immune responses against hypervirulent cc11 and cc334 strains in sera collected from infants/toddlers after priming with a monovalent MenC conjugate vaccine (MenC-CRM; excluded from this analysis, irrespective of their availability for retesting, were those obtained from children enrolled in one of the sites from Germany for which noncompliance with Good Clinical Practices was documented during the conduction of the original phase III study. Retest of samples was allowed by the original informed consent obtained from the childrens parents. Open in a separate window Physique 1. Study design for parent and extension studies Group 2_MenACWY, MenACWY-CRM vaccination at 6C8 and 12?months of age; Group AS2717638 1_MenACWY, AS2717638 MenACWY-CRM vaccination at 12?months of age; Group 1_MenC, MenC-CRM vaccination at 12?months of age. All children received a booster dose of MenACWY-CRM at 22C45?months of age.Note: Visits enclosed in gray boxes correspond to timepoints considered in the analysis. Syringes show vaccine administration (black for MenACWY-CRM and gray for MenC-CRM).Visit 3 was pre-second dose AS2717638 for group 2_MenACWY and pre-first dose for groups 1_MenACWY and 1_MenC; Visit 4 was post-primary vaccination, Visit 7, pre-booster vaccination, Visit 8, post-booster vaccination. Visit 6 (blood sample collection to evaluate persistence of immune response at 6C18?months post-primary vaccination) applied only to children enrolled at the Australian sites. Overall, sera from a randomly selected subset.