Tetanus Toxoid Conjugate Research Articles

Immunogenicity and safety of a quadrivalent meningococcal tetanus toxoid-conjugate vaccine (MenACYW-TT) in healthy toddlers: a Phase II randomized study

ABSTRACT Neisseria meningitidis can lead to invasive meningococcal disease to which young children are particularly vulnerable. We assessed the immunogenicity and safety of Sanofi Pasteur’s investigational quadrivalent (serogroups A, C, Y, and W) meningococcal tetanus-toxoid conjugate vaccine, MenACYW-TT, as a single dose, in healthy meningococcal vaccine-naïve toddlers versus a licensed conjugate vaccine MCV4-TT (NCT03205358). In this Phase II study conducted in Finland, 188 toddlers aged 12–24 months were randomized 1:1 to MenACYW-TT or MCV4-TT. Serum bactericidal antibody assays using human complement (hSBA) and baby rabbit complement (rSBA) measured antibodies against each serogroup before and 30 days after vaccination. Participants were monitored for immediate adverse events (AEs) and post-vaccination AEs for 30 days. All analyses were descriptive. All 188 participants completed the study. The Day 30 hSBA seroresponses (hSBA titer <8 at baseline and post-vaccination titer ≥8, or ≥8 at baseline and ≥4-fold increase post-vaccination) were comparable between participants receiving MenACYW-TT (96.7–100%), and MCV4-TT (86.0–100.0%) for each serogroup. Most unsolicited AEs were of Grade 1 or Grade 2 intensity. There were no immediate hypersensitivity reactions, and no AEs or serious AEs leading to discontinuation from the study. In this exploratory study, MenACYW-TT vaccine was well tolerated and immunogenic. If confirmed in Phase III, a single dose of the MenACYW-TT vaccine may show promise as an alternative vaccine option for toddlers receiving meningococcal vaccination for the first time.

Immunogenicity and safety of a quadrivalent meningococcal tetanus toxoid-conjugate vaccine (MenACYW-TT) in adults 56 years of age and older: a Phase II randomized study

ABSTRACT MenACYW-TT is an investigational quadrivalent meningococcal conjugate vaccine intended for the prevention of invasive meningococcal disease (IMD) caused by serogroups A, C, W, and Y in individuals aged 6 weeks and above. This Phase II, randomized, open-label, multicenter, exploratory study assessed the safety and immunogenicity of MenACYW-TT compared with a quadrivalent meningococcal polysaccharide vaccine (MPSV4) in 301 healthy adults aged ≥56 y in the US (NCT01732627). Participants were randomized 2:1 to receive MenACYW-TT or MPSV4. Serum bactericidal assays using human (hSBA) or baby rabbit (rSBA) complement were used to measure functional antibodies against meningococcal serogroups A, C, W, and Y at baseline and 30 d post-vaccination. Safety data were collected up to 30 d post-vaccination. Proportions of study participants with hSBA titers ≥1:8 against serogroups A, C, W, and Y were increased at Day 30 compared with baseline in both vaccine groups. The proportions of participants with hSBA titers ≥1:8 after MenACYW-TT vaccination were comparable to those after MPSV4 vaccination for serogroups A and C (A: 93.8% vs. 85.1%; C: 74.9% vs. 62.8%) and distinctly higher than after MPSV4 for serogroups W and Y (W: 79.5% vs. 60.6%; Y: 80.5% vs. 59.6%). Proportions of participants with rSBA titers ≥1:8 were comparable between vaccine groups for all four serogroups. The reactogenicity profiles of both vaccines were similar. Most unsolicited adverse events (AEs) were of Grade 1 or Grade 2 intensity, and no serious AEs were reported. The MenACYW-TT conjugate vaccine was well tolerated and immunogenic in adults aged ≥56 y.

Immunogenicity and safety of a booster dose of a quadrivalent meningococcal tetanus toxoid-conjugate vaccine (MenACYW-TT) in adolescents and adults: a Phase III randomized study

ABSTRACT The quadrivalent meningococcal tetanus toxoid-conjugate vaccine (MenACYW-TT) was assessed as a booster in this Phase III trial (NCT02752906). Quadrivalent meningococcal conjugate vaccine (MCV4)-primed individuals aged ≥15 y (n = 810) were randomized 1:1 to receive a single booster dose of MenACYW-TT (n = 403) or a licensed MCV4 (Menactra®; MCV4-DT [n = 407]). Serum bactericidal antibody assay with human complement (hSBA) was used to measure functional antibodies against serogroups A, C, W, and Y at baseline and Day 30 post-vaccination. Proportions of participants achieving seroresponse (post-vaccination titer ≥1:16 for those with baseline titer <1:8 or ≥4-fold increase in post-vaccination titer for those with baseline titer ≥1:8) were determined. Safety data were collected for 180 d post-vaccination. Non-inferiority of the immune response was demonstrated for MenACYW-TT compared with MCV4-DT based on the proportion of participants achieving hSBA vaccine seroresponse for each of the meningococcal serogroups at Day 30. Moreover, ≥99% of participants in both study groups had hSBA titers ≥1:8 for the four meningococcal serogroups at Day 30. Reactogenicity profiles were comparable between groups. These Phase III data in adolescents and adults show that MenACYW-TT boosts the immune response in those primed with MCV4 vaccines 4–10 y previously, irrespective of whether MCV4-DT or MCV4-CRM was used for priming.

Safety, reactogenicity, and immunogenicity of a chimpanzee adenovirus vectored Ebola vaccine in children in Africa: a randomised, observer-blind, placebo-controlled, phase 2 trial

During the large 2013-16 Ebola virus outbreak caused by the Zaire Ebola virus, about 20% of cases were reported in children. This study is the first, to our knowledge, to evaluate an Ebola vaccine in children younger than 6 years. We aimed to evaluate the safety, reactogenicity, and immunogenicity of a monovalent, recombinant, chimpanzee adenovirus type-3 vectored Zaire Ebola glycoprotein vaccine (ChAd3-EBO-Z) in a paediatric population. This phase 2, randomised, observer-blind, controlled trial was done in a vaccine centre in Mali and a university hospital centre in Senegal. Healthy children were randomly assigned through a web-based system (1:1; stratified by age group, gender, and centre) to receive ChAd3-EBO-Z (day 0) and meningococcal serogroups A,C,W-135,Y tetanus toxoid conjugate vaccine (MenACWY-TT; month 6), or MenACWY-TT (day 0) and ChAd3-EBO-Z (month 6). The study was observer-blind from study start until interim day 30 analysis and became single-blind as of interim analysis. Primary outcomes assessed were serious adverse events (up to study end, month 12), solicited local or general adverse events (7 days post-vaccination), unsolicited adverse events (30 days post-vaccination), haematological or biochemical abnormalities, and clinical symptoms of thrombocytopenia (day 0-6). As secondary endpoints, we evaluated anti-glycoprotein Zaire Ebola virus antibody titres (ELISA) pre-vaccination and 30 days post-vaccination. This study is registered with ClinicalTrials.gov, NCT02548078. From Nov 11, 2015, to May 9, 2016, of 776 children screened for eligibility, 600 were randomly assigned (200 [33%] in each age strata: 1-5, 6-12, 13-17 years), 300 (50%) to the ChAd3-EBO-Z/MenACWY-TT group and 300 (50%) to the MenACWY-TT/ChAd3-EBO-Z group; all were included in the total vaccinated cohort. Post-day 0 vaccination, the most common solicited injection site symptom was pain (127 [42%] of 300 in the ChAd3-EBO-Z/MenACWY-TT group vs 60 [20%] of 300 in the MenACWY-TT/ChAd3-EBO-Z group); the most common solicited general adverse event was fever (95 [32%] of 300 in the ChAd3-EBO-Z/MenACWY-TT group vs 28 [9%] of 300 in the MenACWY-TT/ChAd3-EBO-Z group). Unsolicited adverse events post-day 0 vaccination were reported by 41 (14%) of 300 participants in the ChAd3-EBO-Z/MenACWY-TT group and 24 (8%) of 300 MenACWY-TT/ChAd3-EBO-Z recipients. Serious adverse events were reported for two (1%) of 300 children in each group; none were considered vaccination related. No clinical symptoms of thrombocytopenia were reported. At day 30, anti-glycoprotein Ebola virus antibody geometric mean concentrations (GMC) in the ChAd3-EBO-Z/MenACWY-TT group were 1564 (95% CI 1340-1826) for those aged 13-17 years, 1395 (1175-1655) for 6-12 years, and 2406 (1942-2979) for 1-5 years. Anti-glycoprotein Ebola virus IgG antibody responses persisted up to 12 months post-vaccination, with a GMC of 716 (95% CI 619-828) for those aged 13-17 years, 752 (645-876) for 6-12 years, and 1424 (1119-1814) for 1-5 years. ChAd3-EBO-Z was immunogenic and well tolerated in children aged 1-17 years. This study provides the first ChAd3-EBO-Z data in a paediatric population. Further development should focus on multivalent approaches including Sudan and Marburg strains, and heterologous prime-boost strategies, for instance using modified vaccinia Ankara-based vaccine to boost the immune response. EU's Horizon 2020 research and innovation programme and GlaxoSmithKline Biologicals SA.

Higher mass meningococcal group C-tetanus toxoid vaccines conjugated with carbodiimide correlate with greater immunogenicity

To examine the link between meningococcal C (MenC) vaccine size and immunogenic response, a panel of MenC glycoconjugate vaccines were prepared differing in chain length, molar mass and hydrodynamic volume. The preparations consisted of different lengths of MenC polysaccharide (PS) covalently linked to monomeric purified tetanus toxoid (TT) carrier protein using the coupling reagent ethylcarbodiimide hydrochloride (EDC). Size exclusion chromatography with multi-angle light scattering (SEC-MALS) and viscometry analysis confirmed that the panel of MenC-TT conjugates spanned masses of 191,500 to 2,348,000 g/mol, and hydrodynamic radii ranging from 12.1 to 47.9 nm. The two largest conjugates were elliptical in shape, whereas the two smallest conjugates were more spherical. The larger conjugates appeared to fit a model described by multiple TTs with cross-linked PS, typical of lattice-like networks described previously for TT conjugates, while the smaller conjugates were found to fit a monomeric or dimeric TT configuration. The effect of vaccine conjugate size on immune responses was determined using a two-dose murine immunization. The two larger panel vaccine conjugates produced higher anti-MenC IgG1 and IgG2b titres after the second dose. Larger vaccine conjugate size also stimulated greater T-cell proliferative responses in an in vitro recall assay, although cytokines indicative of a T-helper response were not measurable. In conclusion, larger MenC-TT conjugates up to 2,348,000 g/mol produced by EDC chemistry correlate with greater humoral and cellular murine immune responses. These observations suggest that conjugate size can be an important modulator of immune response.

2722 B. Efficacy and Safety of a Booster Dose of the MenACWY-TT Vaccine Administered 10 Years After Primary Vaccination with MenACWY-TT or MenACWY-PS

BackgroundThe quadrivalent meningococcal ACWY polysaccharide tetanus toxoid conjugate vaccine (MenACWY-TT; Nimenrix) is licensed in various countries to prevent disease caused by meningococcal serogroups A, C, W, and Y. In a previous study (NCT00464815), subjects aged 11‒17 years received a primary dose of MenACWY-TT or a quadrivalent polysaccharide vaccine (MenACWY-PS). Here, we report the long-term antibody persistence of the primary dose and the immunogenicity and safety of a booster dose given 10 years after primary vaccination of subjects.MethodsParticipants were enrolled from the Philippines and received a booster dose of MenACWY-TT at 10 years postvaccination. Antibody persistence 10 years postprimary vaccination and immunogenicity 1 month after the booster dose were evaluated by serum bactericidal activity assays using rabbit complement (rSBA) to assess the percentages of subjects with titers ≥ 1:8 and ≥ 1:128 and geometric mean titers (GMTs) for each serogroup. Safety was assessed for the booster dose.ResultsOf 229 subjects enrolled in this extension study, 169 and 58 subjects in the MenACWY-TT and MenACWY-PS groups, respectively, completed the booster phase. The percentages of primary MenACWY-TT recipients with prebooster rSBA titers ≥ 1:8 and ≥ 1:128 at year 10 ranged from 71.6%‒90.7% and 64.8%‒85.2% for all serogroups, respectively, compared with 43.1%‒82.4% and 25.5%‒76.5% of primary MenACWY-PS recipients; rSBA GMTs for all serogroups were higher in the MenACWY-TT group than in the MenACWY-PS group at year 10. For the MenACWY-TT and MenACWY-PS groups, respectively, the MenACWY-TT booster dose elicited rSBA titers ≥ 1:8 in 100% and ≥ 98.0% of subjects (figure); 100% and ≥ 96.1% of all subjects had titers ≥ 1:128. For all serogroups, rSBA GMTs at 1 month after the booster dose were higher than before the booster dose. No new safety signals were observed during the booster phase.ConclusionFunctional antibody responses elicited by MenACWY-TT persisted 10 years after primary vaccination; the booster dose was well tolerated and elicited robust immune responses.ClinicalTrials.govNCT03189745, EudraCT # 2013-001512-29. Funded by Pfizer. Disclosures All authors: No reported disclosures.

1478. Efficacy and Safety of a Booster Dose of the MenACWY-TT Vaccine Administered 10 Years After Primary Vaccination with MenACWY-TT or MenACWY-PS

BackgroundThe quadrivalent meningococcal ACWY polysaccharide tetanus toxoid conjugate vaccine (MenACWY-TT; Nimenrix) is licensed in various countries to prevent disease caused by meningococcal serogroups A, C, W, and Y. In a previous study (NCT00464815), subjects aged 11‒17 years received a primary dose of MenACWY-TT or a quadrivalent polysaccharide vaccine (MenACWY-PS). Here, we report the long-term antibody persistence of the primary dose and the immunogenicity and safety of a booster dose given 10 years after primary vaccination of subjects.MethodsParticipants were enrolled from the Philippines and received a booster dose of MenACWY-TT at 10 years postvaccination. Antibody persistence 10 years postprimary vaccination and immunogenicity 1 month after the booster dose were evaluated by serum bactericidal activity assays using rabbit complement (rSBA) to assess the percentages of subjects with titers ≥1:8 and ≥1:128 and geometric mean titers (GMTs) for each serogroup. Safety was assessed for the booster dose.ResultsOf 229 subjects enrolled in this extension study, 169 and 58 subjects in the MenACWY-TT and MenACWY-PS groups, respectively, completed the booster phase. The percentages of primary MenACWY-TT recipients with prebooster rSBA titers ≥ 1:8 and ≥ 1:128 at year 10 ranged from 71.6%‒90.7% and 64.8%‒85.2% for all serogroups, respectively, compared with 43.1%‒82.4% and 25.5%‒76.5% of primary MenACWY-PS recipients; rSBA GMTs for all serogroups were higher in the MenACWY-TT group than in the MenACWY-PS group at year 10. For the MenACWY-TT and MenACWY-PS groups, respectively, the MenACWY-TT booster dose elicited rSBA titers ≥1:8 in 100% and ≥98.0% of subjects (figure); 100% and ≥96.1% of all subjects had titers ≥1:128. For all serogroups, rSBA GMTs at 1 month after the booster dose were higher than before the booster dose. No new safety signals were observed during the booster phase.ConclusionFunctional antibody responses elicited by MenACWY-TT persisted 10 years after primary vaccination; the booster dose was well tolerated and elicited robust immune responses.ClinicalTrials.gov: NCT03189745, EudraCT # 2013-001512-29. Funded by Pfizer. Disclosures All authors: No reported disclosures.

Immunogenicity and safety of a meningococcal serogroups A and C tetanus toxoid conjugate vaccine (MenAC-TT): two immune schedules in toddles aged 12–23 months in China

ABSTRACT Background: This exploratory study aimed to assess the immunogenicity and safety of 1 and 2 doses of meningococcal serogroups A and C tetanus toxoid-conjugate vaccine (MenAC-TT) in toddles. Methods: Healthy participants aged 12–23 months were randomized into two groups to receive 1 or 2 doses of the tested vaccine. The interval was 28 days between two doses. Blood samples were collected at day 0 before the immunization and day 28 post-each dose. Safety observation was conducted during 28 days after each vaccination. Serious adverse event (SAE) was conducted throughout 6 month observation period. Results: Overall 301 toddles were vaccinated. Twenty-eight days post full-course vaccination, ≥97.20% toddles had titers ≥1:8 and ≥81.48% had titers ≥1:128 for MenA and MenC in the two schedules groups. There were no significant differences between the two schedule groups for each titer thresholds and serogroups. Up to month 12 post the first dose, titers ≥1:8 and 1:128 were declined to 71.32–80.83% and 26.67–57.85% for each meningococcal serogroups. Most adverse reactions (ARs) were mild or moderate, and the incidence of grade 3 ARs was below 3.33%. The incidence of redness was significantly higher in the two doses group than that in the one dose group, in terms of grade 1 and grade 2 were higher. No SAEs were considered causally related to vaccination. Conclusion: The MenAC-TT showed similarly safety and immunogenicity profile in toddles with two schedules. It will be more important to provide the data for formulating appropriate immunization strategies in different age groups in China.

Semisynthetic Glycoconjugate Vaccines To Elicit T Cell-Mediated Immune Responses and Protection against Streptococcus pneumoniae Serotype 3.

Streptococcus pneumoniae serotype 3 (ST3) is one of the main pneumococcal strains that can cause severe invasive diseases, but its current vaccines are relatively inefficient. To develop more effective ST3 vaccines, tetanus toxoid (TT) conjugates of the synthetic penta-, hexa-, hepta-, and octasaccharide analogs of ST3 capsular polysaccharide (CPS) were systematically studied. These conjugates, especially those of penta- and hexasaccharides, were demonstrated to induce extremely robust T cell-dependent immune responses in mouse. Various studies also revealed that the induced antibodies could recognize ST3 CPS and mediate in vitro opsonophagocytic killing of ST3 cells. It was proved ultimately that immunization with the hexasaccharide-TT conjugate could completely protect mice from ST3-caused infection and lung damage and significantly elongate mouse survival. It was proposed that this conjugate functions through the help of CD4+ T cells and via promoting Th cell differentiation into carbohydrate antigen-specific Th2 cells to establish humoral immunity. In conclusion, ST3 CPS hexasaccharide-TT was identified as a particularly promising ST3 vaccine candidate worthy of further investigation and development.

Immunogenicity and safety of meningococcal group A, C, W and Y tetanus toxoid conjugate vaccine: review of clinical and real-world evidence.

Protection by meningococcal group A, C, W and Y (MenACWY) vaccines against four meningococcal disease-causing serogroups is increasingly important because of changing epidemiologic patterns of meningococcal disease, including recent meningococcal serogroup W outbreaks/disease clusters. The MenACWY vaccine conjugated to tetanus toxoid (MenACWY-TT) has been extensively evaluated across the age spectrum (age ≥6weeks) in randomized Phase II and III and in postmarketing studies. Results support the robust immunogenicity of MenACWY-TT across ages and coadministration with other vaccines. The safety profile is similar regardless of age, primary versus booster vaccination, or concomitant administration; local (swelling, pain, redness) and systemic (fever, fatigue, headache, drowsiness, loss of appetite, irritability) reactogenicity events are most common. These data support use of MenACWY-TT to protect against MenACWY disease.

Immunogenicity and safety of the Haemophilus influenzae type b and Neisseria meningitidis serogroups C and Y-tetanus toxoid conjugate vaccine co-administered with human rotavirus, hepatitis A and 13-valent pneumococcal conjugate vaccines: results from a phase III, randomized, multicenter study in infants

ABSTRACTThis phase III, open-label, randomized study (NCT01978093) evaluated the immunogenicity and safety of co-administered Haemophilus influenzae type b–Neisseria meningitidis serogroups C and Y–tetanus toxoid conjugate vaccine (Hib-MenCY-TT) with human rotavirus vaccine (HRV), hepatitis A vaccine (HAV) and 13-valent pneumococcal conjugate vaccine (PCV13). We randomized 600 infants (1:1) to receive 4 doses of Hib-MenCY-TT at 2, 4, 6 and 12–15 months of age or 3 doses of Hib vaccine conjugated to N. meningitidis outer membrane protein complex (Hib-OMP) at 2, 4 and 12–15 months of age. All infants received HRV at 2 and 4 months of age, PCV13 at 2, 4, 6 and 12–15 months of age, HAV at 12–15 and 18–21 months of age, and diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus vaccine at 2, 4 and 6 months of age. We measured immune responses against HRV, HAV and Hib with enzyme-linked immunosorbent assays, and against MenC/MenY with serum bactericidal assays using human complement. The 4-dose vaccination series with Hib-MenCY-TT induced a robust immune response against Hib, which was non-inferior to that induced by a 3-dose vaccination series with Hib-OMP, and against MenC and MenY. Hib-MenCY-TT did not interfere with immune responses to concomitantly administered HRV, PCV13 and HAV. We did not identify any safety concern. In conclusion, we showed that 4-dose vaccination series with Hib-MenCY-TT during infancy did not interfere with immune responses of co-administered HRV, PCV13 and HAV, induced robust immune responses against Hib, MenC and MenY, and had a clinically acceptable safety profile.

Vaccines for preventing typhoid fever.

Vaccines for preventing typhoid fever.

MenACWY-TT is immunogenic when co-administered with Tdap and AS04-HPV16/18 in girls and young women: Results from a phase III randomized trial

BackgroundCo-administration of vaccines in adolescents may improve coverage. We assessed co-administration of quadrivalent meningococcal serogroups A, C, W and Y tetanus toxoid-conjugate vaccine (MenACWY-TT), human papillomavirus 16/18 AS04-adjuvanted vaccine (AS04-HPV16/18) and tetanus-diphtheria-acellular pertussis vaccine (Tdap) in girls and young women. MethodsIn this phase IIIb study (NCT01755689), 1300 healthy 9–25-year-old females were randomized (1:1:1:1:1) to receive: MenACWY-TT at month (M) 0 and AS04-HPV16/18 at M1, M2, M7; MenACWY-TT and AS04-HPV16/18 at M0 and AS04-HPV16/18 at M1, M6; AS04-HPV16/18 at M0, M1, M6; MenACWY-TT, Tdap and AS04-HPV16/18 at M0 and AS04-HPV16/18 at M1, M6; Tdap and AS04-HPV16/18 at M0 and AS04-HPV16/18 at M1, M6. Immunogenicity, safety and reactogenicity were evaluated. ResultsImmunogenicity of MenACWY-TT and AS04-HPV16/18 when co-administered was non-inferior to that of the 2 vaccines given separately. Co-administration of MenACWY-TT, AS04-HPV16/18 and Tdap was non-inferior to MenACWY-TT administered alone or to Tdap co-administered with AS04-HPV16/18 in terms of immunogenicity for all vaccine components, except pertussis antigens. Post-vaccination, ≥89.5% of participants reached antibody levels above the pre-specified threshold for all antigens. No safety concerns were identified. ConclusionOur data support co-administration of MenACWY-TT with Tdap and AS04-HPV16/18 vaccines in adolescents.

Antibody persistence and booster response 68 months after vaccination at 2–10 years of age with one dose of MenACWY-TT conjugate vaccine

BackgroundWe evaluated antibody persistence up to 68 months (M) post-vaccination with a quadrivalent meningococcal serogroups A, C, W and Y tetanus toxoid conjugate vaccine (MenACWY-TT) or a licensed monovalent MenC conjugate vaccine (MenC-CRM197) and subsequent booster responses to MenACWY-TT in healthy European children. MethodsIn the initial study (NCT00674583), healthy children, 2–10 years of age, were randomized to receive a single dose of either MenACWY-TT or MenC-CRM197. In the follow-up study, we present the persistence at 32, 44, 56, and 68 M post-vaccination, overall and stratified by age (2–5 and 6–10 years), and the immunogenicity and safety of MenACWY-TT administered to all study participants at M68 post-primary vaccination. ResultsAt M68, 33.3% (age group 2–5 years) and 47.1% (age group 6–10 years) of the children vaccinated with MenACWY-TT, and 50.0% (age group 2–5 years) and 75.9% (age group 6–10 years) vaccinated with MenC-CRM197 retained titers ≥1:8 for MenC, as assessed by a serum bactericidal assay using rabbit complement (rSBA). In the MenACWY-TT recipients, the percentages of children retaining rSBA titers ≥1:8 for MenA, MenW, and MenY were 81.7%, 47.3% and 66.7% in age group 2–5 years and 91.8%, 58,8% and 76.5% in age group 6–10 years, respectively. The booster dose induced robust responses (100% for all serogroups) and was well-tolerated. ConclusionsAntibody persistence (rSBA titers ≥ 1:8) for serogroups A, W and Y was observed in more than 50.0% of the children 68 M after receiving one dose of MenACWY-TT; for MenC, antibody persistence was observed in more than one third of MenACWY-TT and more than half of MenC-CRM197 recipients. Vaccination with a booster dose of MenACWY-TT induced robust immune responses for all serogroups.

Immunogenicity and safety of the quadrivalent meningococcal ACWY-tetanus toxoid conjugate vaccine (MenACWY-TT) in splenectomized or hyposplenic children and adolescents: Results of a phase III, open, non-randomized study

BackgroundIndividuals with functional or anatomic asplenia are at high risk for meningococcal disease. We evaluated the immunogenicity and safety of 1 and 2 doses of the quadrivalent meningococcal serogroups A, C, W, Y tetanus toxoid-conjugate vaccine (MenACWY-TT) in this high-risk population. MethodsThis phase III, open-label, controlled, non-randomized study (NCT01641042) enrolled 1–17-year-olds with impaired splenic activity (high-risk group) and age-matched healthy controls (control group). We measured immune responses to MenACWY-TT by serum bactericidal activity assays using rabbit (rSBA) and human (hSBA) complement and in terms of antibodies against polysaccharides of the 4 vaccine serogroups. We evaluated vaccine response rates (VRRs) as 4-fold increases from pre-vaccination levels or titers ≥1:32 (rSBA)/≥1:8 (hSBA). We recorded solicited and unsolicited adverse events (AEs) during 4 and 31 days post-vaccination, and serious AEs (SAEs) and new onset of chronic illnesses (NOCIs) throughout the study. ResultsThe according-to-protocol cohort for immunogenicity included 40 participants per group. In both groups, the first MenACWY-TT dose induced rSBA VRRs of 92.5–100% and hSBA VRRs of 55.6–77.1% across vaccine serogroups. Following the second MenACWY-TT dose, all participants had high responses, with rSBA and hSBA VRRs of 73.0–100% across vaccine serogroups. rSBA and hSBA geometric mean titers for each serogroup increased in both groups (with different magnitudes, but ≥13.1-fold) compared with baseline levels. Polysaccharide antibody concentrations ≥2.0 μg/ml were detected in ≥84.4% of participants and were similar between groups. Incidences of solicited and unsolicited AEs were comparable between groups. We recorded SAEs in 4/43 participants in the high-risk group and 1/43 participants in the control group (none vaccine-related). No NOCIs were reported. ConclusionIn this descriptive study, MenACWY-TT induced similar functional and humoral immune responses and had a clinically acceptable safety profile in children and adolescents with impaired splenic activity and in healthy controls.

A Review of Meningococcal Disease and Vaccination Recommendations for Travelers.

International travel has been steadily increasing since the middle of the twentieth century, including travel to regions with high levels of endemic meningococcal disease and areas with sporadic or sustained meningococcal outbreaks. Although invasive meningococcal disease (IMD) is relatively rare in travelers since the advent of quadrivalent meningococcal vaccines, it remains a serious concern because of its rapid progression, poor prognosis and outcomes, associated treatment delays, and the potential to precipitate outbreaks. Moreover, fatality occurs in up to 22% of those infected. This review will focus on IMD in travelers, with an emphasis on IMD epidemiology and the geographic regions of potential concern for international travelers. As vaccination is the best approach for preventing IMD among travelers, currently available meningococcal vaccines and corresponding country-specific national meningococcal vaccination recommendations, where available, will be summarized by age and type of vaccine recommended. The use of the quadrivalent meningococcal vaccines, specifically the tetanus toxoid conjugate vaccine (including MenACWY-TT; Nimenrix®), as a protective measure against IMD in travelers will be emphasized.FundingPfizer Inc.

Immunogenicity and safety of one or two doses of the quadrivalent meningococcal vaccine MenACWY-TT given alone or with the 13-valent pneumococcal conjugate vaccine in toddlers: A phase III, open-label, randomised study

BackgroundWe evaluated the immunogenicity and safety of 1 and 2 doses of quadrivalent meningococcal serogroup A, C, W and Y tetanus toxoid-conjugate vaccine (MenACWY-TT) given alone or co-administered with 13-valent pneumococcal conjugate vaccine (PCV13) in toddlers. MethodsIn this phase III, open-label, controlled, multicentre study (NCT01939158), healthy toddlers aged 12–14 months were randomised into 4 groups to receive 1 dose of MenACWY-TT at month (M) 0 (ACWY_1), 2 doses of MenACWY-TT at M0 and M2 (ACWY_2), MenACWY-TT and PCV13 at M0 (Co-ad), or PCV13 at M0 and MenACWY-TT at M2 (PCV13/ACWY). Immune responses were assessed 1 month post-each vaccination. Solicited and unsolicited symptoms were recorded for 4 and 31 days post-each vaccination, respectively; serious adverse events (SAEs) and new onset of chronic illnesses (NOCIs) up to M9 from first vaccination. Results802 toddlers were vaccinated. Post-dose 1 of MenACWY-TT, ≥92.8% of toddlers had rSBA titres ≥1:8, and ≥62.5% had hSBA titres ≥1:4 for each meningococcal serogroup. Post-dose 2 of MenACWY-TT, rSBA titres ≥1:8 were observed in ≥98.0% and hSBA titres ≥1:4 in ≥95.3% of toddlers. Percentages of toddlers with hSBA titres ≥1:4 were higher after 2 doses versus 1 dose of MenACWY-TT for MenW (97.1% versus 62.5–68.9%) and MenY (95.3% versus 64.3–67.6%). Non-inferiority of immune responses to co-administered MenACWY-TT and PCV13 over their separate administration was demonstrated. AEs incidence was comparable among groups. SAEs were reported for 4.9%, 5.1%, 5.5% and 7.5%, and NOCIs for 2.0%, 3.0%, 0.5% and 3.5% of toddlers in the ACWY_1, ACWY_2, Co-ad and PCV13/ACWY groups, respectively; 4 SAEs reported in 3 toddlers were vaccine-related. Two fatal vaccine-unrelated SAEs were reported. ConclusionMenACWY-TT was immunogenic when administered as a single dose at 12–14 months of age. A second dose in toddlers increased hSBA responses against MenW and MenY. MenACWY-TT and PCV13 can be co-administered without impairing the immunogenicity or safety profile of either vaccine.

Comparison of serum bactericidal and antibody titers induced by two Haemophilus influenzae type b conjugate vaccines: A phase III randomized double-blind study

Haemophilus influenzae type b (Hib) conjugate vaccines have drastically reduced disease incidence worldwide. Protection against Hib infection has relied on the serum bactericidal activity (SBA) of antibodies to the Hib capsular polysaccharide (polyribosylribitol phosphate). However, licensure usually relies on measuring induction of antibodies to PRP as a surrogate for SBA. In a phase III clinical trial we compared a PRP-conjugate vaccine using the nontoxic diphtheria toxin mutant, CRM197, as carrier protein with the licensed tetanus toxoid conjugate when administered subcutaneously as a three dose primary series in Japanese infants. As an addition to the phase III study, we have now evaluated SBA and show PRP-CRM197 induces higher levels of SBA than PRP-T four weeks after the primary series, with a statistically significant correlation with anti-PRP titers. This data confirms the superior immunogenicity of PRP-CRM197 compared with PRP-T assessed as SBA following a three-dose primary series by subcutaneous administration.Clinical trial registry: Registered on ClinicalTrials.gov (NCT01379846).

Meningococcal Quadrivalent Tetanus Toxoid Conjugate Vaccine (MenACWY-TT; Nimenrix®): A Review.

MenACWY-TT (Nimenrix®) is a quadrivalent meningococcal tetanus toxoid conjugate vaccine licensed in Europe for active immunisation of individuals aged ≥6 weeks against invasive disease caused by Neisseria meningitidis capsular groups A, C, W and Y. MenACWY-TT is the first quadrivalent conjugate vaccine to be approved in Europe for use in infants as young as 6weeks of age. Numerous phase II-IIIb clinical studies showed that intramuscular MenACWY-TT administered as primary or booster vaccination was highly immunogenic for all four vaccine capsular groups and had an acceptable reactogenicity profile in individuals aged 6 weeks to ≥56years. MenACWY-TT is as immunogenic and safe as other previously licensed monovalent capsular group C or quadrivalent capsular groups A, C, W and Y meningococcal vaccines and can be coadministered with other routine vaccines without adversely affecting the immunogenicity or safety profiles of either vaccine. Current data indicate that primary and booster vaccination with MenACWY-TT is a valuable and safe option for broadening meningococcal protection against four capsular groups across a broad age range, starting as early as 6weeks of age.

Lot-to-lot consistency, safety and immunogenicity of 3 lots of Haemophilus influenzae type b conjugate vaccine: results from a phase III randomized, multicenter study in infants

BackgroundVaccination against Haemophilus influenzae type b (Hib) is included in routine pediatric immunization schedule in the United States. Previous vaccine shortages have created the need for additional options for Hib vaccination. MethodsThis phase III, randomized, multi-centered study (NCT01000974) evaluated the safety and immunogenicity of a monovalent tetanus toxoid-conjugate Hib vaccine (Hib-TT) compared to a monovalent (Hib-TT control) and a combination Hib-TT vaccine. We hierarchically assessed lot-to-lot consistency of 3 Hib-TT lots and non-inferiority of Hib-TT to Hib-TT control. We co-administered routine pediatric vaccines with Hib-TT vaccines at 2, 4, 6months (primary vaccination) and 15–18months of age (booster vaccination). We recorded adverse events (AEs) for 4 (solicited) and 31days (unsolicited) post-vaccination and serious AEs (SAEs) throughout the study. ResultsOf 4009 enrolled children, 3086 completed booster phase. Lot-to-lot consistency was not demonstrated. The study met statistical criteria for non-inferiority of Hib-TT to Hib-TT control in terms of immune responses to Hib and co-administered vaccines’ antigens, but not in terms of participants achieving post-primary vaccination anti-PRP levels ≥1µg/mL. Because of the hierarchical nature of the objectives, non-inferiority could not be established. In all groups, 92.5–96.7% and 99.6–100% of participants achieved anti-PRP levels ≥0.15µg/mL, while 78.3–89.8% and 97.9–99.1% had anti-PRP levels ≥1µg/mL, post-primary and post-booster vaccination, respectively. Immune responses to co-administered vaccines and reported incidence of AEs were comparable among groups. We recorded SAEs for 107/2963 (3.6%), 24/520 (4.6%), and 21/520 (4.0%) children post-primary vaccination, and 29/2337 (1.2%), 4/435 (0.9%), and 2/400 (0.5%) children post-booster vaccination with Hib-TT, Hib-TT control and combination Hib-TT vaccine, respectively; 6/5330 (0.1%) SAEs in the Hib-TT groups were considered vaccine-related. ConclusionHib-TT induced seroprotective antibody concentrations in the majority of participants and was well-tolerated when co-administered with routine pediatric vaccines according to a 3+1 schedule.