Experience with MCV-4, a meningococcal, diphtheria toxoid conjugate vaccine against serogroups A, C, Y and W-135

Immunogenicity of the meningococcal polysaccharide conjugate vaccine in pediatric kidney transplant patients

BACKGROUND

Immunosuppressed kidney transplant patients may have suboptimal response to vaccinations. The aim of this study was to determine antibody response to a quadrivalent meningococcal conjugate vaccine (MenACWY-D) in adolescents with a kidney transplant.

METHODS

This was a prospective, single-center, cohort study. Adolescent patients (11-22 years old) with a functioning kidney transplant for at least 3 months and no previous meningococcal vaccination were eligible for enrollment. Antibody levels to all serogroups were measured before vaccination (baseline) and at 4 weeks and 1, 2 and 3 years after vaccination. Seropositivity was defined as a titer ≥ 1:8 at baseline, and seroconversion as a fourfold or greater increase in antibody titer from baseline at 4 weeks post-vaccination. Geometric mean titers (GMTs) were calculated at each time point and compared to published GMTs from vaccinated healthy adolescents.

RESULTS

Nineteen patients were enrolled. No patient had seroprotective titers against all four serogroups at baseline. At 4 weeks post-vaccination 41% of patients seroconverted to all four serogroups, with seroconversion rates of 88, 53, 71 and 94% for serogroups A, C, W and Y, respectively. GMTs were significantly lower in adolescents with a kidney transplant than in healthy adolescents at 1 month (p = 0.02) and 3 years (p = 0.04) post-vaccination. There were no significant adverse events, episodes of rejection or death in any patient.

CONCLUSIONS

Adolescents with a kidney transplant may not respond adequately to MenACWY-D and may experience more rapid declines in antibody titers than healthy adolescents. Further study is needed to determine if alternative dosing schedules can improve antibody response in this population.

Immunogenicity and safety of investigational vaccine formulations against meningococcal serogroups A, B, C, W, and Y in healthy adolescents

This phase 2 study assessed the immunogenicity, safety, and reactogenicity of investigational formulations of meningococcal ABCWY vaccines, consisting of recombinant proteins (rMenB) and outer membrane vesicle (OMV) components of a licensed serogroup B vaccine, combined with components of a licensed quadrivalent meningococcal glycoconjugate vaccine (MenACWY-CRM). A total of 495 healthy adolescents were randomized to 6 groups to receive 2 doses (Months 0, 2) of one of 4 formulations of rMenB antigens, with or without OMV, combined with MenACWY-CRM, or 2 doses of rMenB alone or one dose of MenACWY-CRM then a placebo. Immunogenicity was assessed by serum bactericidal assay with human complement (hSBA) against serogroups ACWY and serogroup B test strains; solicited reactions and any adverse events (AEs) were assessed. Two MenABCWY vaccinations elicited robust ACWY immune responses, with higher seroresponse rates than one dose of MenACWY-CRM. Bactericidal antibody responses against the rMenB antigens and OMV components were highest in subjects who received 2 doses of OMV-containing MenABCWY formulations, with ≥68% of subjects achieving hSBA titers ≥5 against each of the serogroup B test strains. After the first dose, solicited local reaction rates were higher in the MenABCWY or rMenB groups than the MenACWY-CRM group, but similar across groups after the second dose, consisting mainly of transient injection site pain. Fever (≥38.0°C) was rare and there were no vaccine-related serious AEs. In conclusion, investigational MenABCWY formulations containing OMV components elicited highly immunogenic responses against meningococcal serogroups ACWY, as well as serogroup B test strains, with an acceptable safety profile. [NCT01210885].

Immunogenicity and Safety of a 3- and 4-dose Vaccination Series of a Meningococcal ACWY Conjugate Vaccine in Infants: Results of a Phase 3b, Randomized, Open-label Trial

BACKGROUND

The quadrivalent meningococcal glycoconjugate vaccine MenACWY-CRM is licensed for children from 2 months of age as a 4-dose series. This study assessed the immunogenicity of a 3-dose MenACWY-CRM vaccination series in infants, compared with the 4-dose series, and evaluated the impact of MenACWY-CRM concomitant administration on immune responses to the 13-valent pneumococcal conjugate vaccine (PCV13).

METHODS

Overall, 751 healthy infants (age: 55-89 days) were randomized to receive 3 or 4 doses of MenACWY-CRM (2/4/12 or 2/4/6/12 months of age, respectively) with PCV13 + routine vaccinations (ACWY3 and ACWY4 groups, respectively) or PCV13 + routine vaccinations only (routine group). Immunological noninferiority of the 3-dose versus 4-dose MenACWY-CRM vaccination series was evaluated at 13 months of age for serogroups CWY; noninferiority of immune responses to PCV13 serotypes for concomitant administration of MenACWY-CRM and PCV13 was evaluated at 7 and 13 months of age.

RESULTS

At 13 months, 88%-100% of subjects in groups ACWY3 and ACWY4 achieved seroprotective bactericidal antibody titers against serogroups ACWY; noninferiority criteria for the 3-dose versus 4-dose MenACWY-CRM vaccination series were met. At 7 months, noninferiority criteria were met for all PCV13 serotypes except for serotypes 3 and 5 (group ACWY3) and 19A (group ACWY4). At 13 months, noninferiority criteria were met for all PCV13 serotypes for both ACWY groups.

CONCLUSIONS

After completion of either MenACWY-CRM vaccination series, most subjects achieved seroprotective titers against serogroups ACWY, with the 3-dose series being noninferior to the 4-dose series for serogroups CWY, and no interference with immune responses against PCV13 serotypes was observed (NCT01214837).

Safety and immunogenicity of a quadrivalent meningococcal conjugate vaccine (MenACYW-DT): a multicenter, open-label, non-randomized, phase III clinical trial

OBJECTIVE

To assess the safety and immunogenicity of a quadrivalent meningococcal (groups A,C,Y,W) polysaccharide diphtheria toxoid conjugate vaccine (MenACYW-DT) in India.

DESIGN

Open-label, descriptive, non-randomized study.

SETTING

Three medical college hospitals, one each in New Delhi, Bengaluru and Mumbai, India.

PARTICIPANTS

300 healthy, vaccine-naïve participants (100 children aged 2-11 years, 100 adolescents aged 12-17 years, and 100 adults aged 18-55 years).

INTERVENTION

One dose (0.5 mL) of MenACYW-DT administered intramuscularly.

MAIN OUTCOME MEASURES

Serum bactericidal antibody titers against A, C, Y, and W were measured before and after MenACWY-DT vaccination. Safety data were also collected.

RESULTS

Thirty days post-vaccination, geometric mean titers rose across all serogroups. Most participants had protective titers >8 (1/dil) across the four serogroups. The percentage (95% CI) achieving >8 (1/dil) in the Adolescent Group was typical - A: 96.9% (91.2%; 99.4%); C: 96.9% (91.2%; 99.4%); Y:100% (96.3%; 100%); W:100% (96.3%; 100%). In general, solicited reactions were mild and short-lived. Unsolicited events were uncommon and unrelated to vaccination.

CONCLUSIONS

MenACYW-DT was well tolerated and elicited a robust and protective immune response 30 days post-vaccination against meningococcal serogroups A, C, Y, and W-135 in the Indian study participants aged 2-55 years.

A comparative evaluation of two investigational meningococcal ABCWY vaccine formulations: Results of a phase 2 randomized, controlled trial

BACKGROUND

A meningococcal vaccine protective against all major disease-associated serogroups (A, B, C, W and Y) is an unmet public health need. In this phase 2 observer-blinded, randomized, controlled study, two investigational meningococcal ABCWY vaccine formulations were evaluated to assess their immunological noninferiority to a licensed quadrivalent meningococcal ACWY glycoconjugate vaccine (MenACWY-CRM) for serogroups ACWY and immunogenicity against serogroup B test strains, as well as for formulation selection based on a desirability index (DI). Each investigational MenABCWY formulation contained recombinant protein and outer membrane vesicle (OMV) components of a licensed serogroup B vaccine (4CMenB) combined with components of MenACWY-CRM.

METHODS

A total of 484 healthy 10-25 year-old participants were randomized to receive two doses, two months apart, of an investigational MenABCWY formulation that contained either a full or one-quarter dose of OMV, 4CMenB alone, or a Placebo followed by MenACWY-CRM. Immunogenicity against each of serogroups ACWY and four serogroup B test strains was assessed by serum bactericidal assay with human complement (hSBA). MenABCWY formulations were compared by a DI based on key immunogenicity and reactogenicity parameters.

RESULTS

Seroresponse rates for serogroups ACWY were significantly higher after two doses of either MenABCWY formulation than after one dose of MenACWY-CRM: respectively, A: 90-92% vs. 73%; C: 93-95% vs. 63%; W: 80-84% vs. 65%; and Y: 90-92% vs. 75%. Prespecified noninferiority criteria were met. Both MenABCWY formulations induced substantial immune responses against serogroup B test strains, although 4CMenB responses were higher. Overall DIs for both MenABCWY formulations were similar. Reactogenicity profiles of the MenABCWY formulations were similar to each other and to that of 4CMenB. No vaccine-related serious adverse events were reported.

CONCLUSIONS

Both investigational MenABCWY formulations elicited robust immune responses against serogroups ACWY and serogroup B test strains, and had acceptable reactogenicity profiles, with no safety concerns identified.

Trends in meningococcal disease in the United States military, 1971-2010

When you consider the risks undertaken by US military personnel, do you include risk for disease? Public health officials do. Military personnel are at risk for infectious disease because of crowding, the rigors of physical training, and sometimes unhygienic field conditions. Meningococcal disease (usually manifested as bacterial meningitis or blood-borne infection) can be rapidly fatal. It has historically affected the military more than the general US population. One hundred years' worth of data support this trend from as long ago as World War I. However, in 1970, a policy requiring vaccination of military recruits started lowering the rate of infection, although the rate remained higher than that for the general population. Since 1982, improvements in vaccines have lowered rates even further. As a result of these vaccination efforts, the meningococcal disease rate among military personnel has reached a historic low, which now matches that of the general population.

Meningococci have historically caused extensive illness among members of the United States military. Three successive meningococcal vaccine types were used from 1971 through 2010; overall disease incidence dropped by >90% during this period. During 2006–2010, disease incidence of 0.38 (cases per 100,000 person-years) among members of the US military was not significantly different from the incidence of 0.26 among the age-matched US general population. Of the 26 cases in the US military, 5 were fatal, 15 were vaccine failures (e.g., illness in a person who had been vaccinated), and 9 were caused by Neisseria meningitidis serogroup Y. Incidences among 17- to 19-year-old basic trainees and among US Marines were significantly higher than among comparison military populations (p<0.05). No apparent change in epidemiology of meningococcal disease was observed after replacement of quadrivalent polysaccharide vaccine with conjugate vaccine in 2007. The data demonstrate that vaccination with meningococcal vaccine is effective.

Safety and immunogenicity of a quadrivalent meningococcal polysaccharide diphtheria toxoid conjugate vaccine in infants and toddlers: three multicenter phase III studies

BACKGROUND

Quadrivalent meningococcal conjugate vaccine (Menactra [MenACWY-D]), was licensed in the United States in 2005 to prevent meningococcal disease in adolescents and adults. The license was extended to children aged 2-10 years in 2007 and extended again in 2011 to infants aged 9 months and older based, in part, on results from 3 phase III studies presented herein.

METHODS

The safety and immunogenicity of 2 doses of MenACWY-D was assessed in study-eligible children: dose 1 was administered at 9 months of age and dose 2 was administered 3 months later with or without routine childhood vaccines.

RESULTS

Thirty days after vaccination, protective serum bactericidal assay-human complement titers ≥1:8 for meningococcal serogroups A, C, Y and W-135 were achieved by 86-100% of children receiving 2 doses of MenACWY-D. When MenACWY-D was concomitantly administered with measles, mumps, rubella and varicella or heptavalent pneumococcal conjugate vaccine, 81-98% of participants achieved protective responses (serum bactericidal assay-human complement titers ≥1:8 for all serogroups). All seroprotection rates were >91% when the protective titer was defined as serum bactericidal assay-human complement ≥1:4. MenACWY-D did not interfere with measles, mumps, rubella or varicella vaccine responses (98-100% achieved protective titers). When heptavalent pneumococcal conjugate vaccine was given concomitantly with MenACWY-D, antipneumococcal antibody levels, although decreased, were protective for all serotypes by enzyme-linked immunosorbent assay (98-100% ≥ 0.35 μg/mL) and opsonophagocytic assay (99-100% ≥ 1:8). Adverse events were generally mild and similar across groups. Serious adverse events were uncommon.

CONCLUSIONS

MenACWY-D was safe and immunogenic when given in 2 doses to infants and toddlers; this vaccine can be given with other common childhood immunizations.

Genetic and antigenic analysis of invasive serogroup C Neisseria meningitidis in Canada: A decrease in the electrophoretic type (ET)-15 clonal type and an increase in the proportion of isolates belonging to the ET-37 (but not ET-15) clonal type during the period from 2002 to 2009

BACKGROUND

Serogroup C meningococcal disease has been endemic in Canada since the early 1990s, with periods of hyperendemic disease documented in the past two decades. The present study characterized invasive serogroup C meningococci in Canada during the period from 2002 to 2009.

METHODS

Serogroup C meningococci were serotyped using monoclonal antibodies. Their clonal types were identified by either multilocus enzyme electrophoresis or multilocus sequence typing.

RESULTS

The number of invasive serogroup C Neisseria meningitidis isolates received at the National Microbiology Laboratory (Winnipeg, Manitoba) for characterization has dropped from a high of 173 isolates in 2001 to just 17 in 2009, possibly related to the introduction of the serogroup C meningococcal conjugate vaccine. Before 2006, 80% to 95% of all invasive serogroup C meningococci belonged to the electrophoreic type (ET)-15 clonal type, and the ET-37 (but not ET-15) type only accounted for up to 5% of all isolates. However, beginning in 2006, the percentage of the ET-15 clonal type decreased while the ET-37 (but not ET-15) type increased from 27% in 2006 to 52% in 2009. The percentage of invasive serogroup C isolates not belonging to either ET-15 or ET-37 also increased. Most ET-15 isolates expressed the antigenic formula of C:2a:P1.7,1 or C:2a:P1.5. In contrast, the ET-37 (but not ET-15) isolates mostly expressed the antigens of C:2a:P1.5,2 or C:2a:P1.2.

CONCLUSION

A shift in the antigenic and clonal type of invasive serogroup C meningococi was noted. This finding suggests vigilance in the surveillance of meningoccocal disease is warranted.

A novel combined Haemophilus influenzae type b-Neisseria meningitidis serogroups C and Y-tetanus-toxoid conjugate vaccine is immunogenic and induces immune memory when co-administered with DTPa-HBV-IPV and conjugate pneumococcal vaccines in infants

Immunogenicity and safety of a novel combined Haemophilus influenzae type b-Neisseria meningitidis serogroups C and Y-tetanus-toxoid conjugate vaccine (Hib-MenCY-TT) candidate was evaluated when co-administered with DTPa-HBV-IPV(Pediarix)+PCV7(Prevnar) at 2-4-6 months of age. Anti-PRP concentrations >or= 1.0 microg/mL were observed in 92.9-98.7%, rSBA-MenC/Y titres >or= 1:8 in >98%, rSBA-MenC/Y titres >or= 1:128 in >95.8 and >89.9% subjects. PRP and MenC responses were similar to respective controls (ActHIB and Menjugate) including for antibody persistence. Response to co-administered vaccines was not impaired. Polysaccharide challenge (PRP, PSC, PSY at 11-14 months of age) evidenced immune memory was induced for Hib, MenC/Y conjugate components. The safety profile of Hib-MenCY-TT was similar to controls. Hib-MenCY-TT administered according to the current US Hib vaccine schedule has the potential to induce protective antibodies against Hib and meningococcal-CY disease in infants and toddlers.