Immunogenicity and safety of the 4CMenB and MenACWY-CRM meningococcal vaccines administered concomitantly in infants: A phase 3b,randomized controlled trial

BackgroundInvasive meningococcal disease has its highest incidence in infants. Co-administration of serogroup B (4CMenB) and quadrivalent conjugate (MenACWY-CRM) vaccines could protect against 5 clinically-relevant meningococcal serogroups.MethodsThis phase 3b, open, multicenter study (NCT02106390), conducted in Mexico and Argentina, enrolled and randomized (1:1:1) 750 healthy infants to receive either 4CMenB co-administered with MenACWY-CRM (4CMenB/MenACWY group), 4CMenB (4CMenB group), or MenACWY-CRM alone (MenACWY group) at ages 3, 5, 7 and 13 months. Non-inferiority of immune responses of co-administration to single administration of vaccines was assessed at 1 month post-booster dose (primary objective). Immunogenicity was evaluated pre- and 1 month post-primary and booster vaccinations using human serum bactericidal assay (hSBA). Safety was assessed.ResultsAt 1 month post-booster vaccination, between-group hSBA geometric mean titer (GMT) ratios ranged from 0.89 to 1.03 for serogroup B strains (group 4CMenB/MenACWY over 4CMenB), and from 1.05 to 2.48 for ACWY serogroups (group 4CMenB/MenACWY over MenACWY). The lower limit of the 2-sided 95% confidence intervals for all GMT ratios was >0.5; the primary objective was demonstrated. Across all groups and serogroup B strains, 68–100% and 87–100% of children had hSBA titers ≥5 at 1 month post-primary and booster vaccination, respectively. For serogroups ACWY, ≥96% (post-primary vaccination) and ≥98% (post-booster vaccination) of children in all groups had hSBA titers ≥4. Post-booster vaccination, GMTs increased ≥5.99-fold from pre-booster values for each strain/serogroup. Solicited adverse events (AEs) were more frequent in groups 4CMenB/MenACWY and 4CMenB than in MenACWY; incidence of all other AEs was similar between groups. Serious AEs were reported for 6, 13, and 11 participants in groups 4CMenB/MenACWY, 4CMenB, and MenACWY, respectively; 1 (group 4CMenB) was considered vaccine-related.ConclusionImmune responses elicited by co-administration of 4CMenB and MenACWY-CRM was non-inferior to single immunization. Co-administration of vaccines was immunogenic and well tolerated in infants.ClinicalTrials.gov: NCT02106390.An Audio Summary linked to this article that can be found on Figshare https://figshare.com/articles/Immunogenicity_and_safety_of_the_4CMenB_and_MenACWY-CRM_meningococcal_vaccines_administered_concomitantly_in_infants_-_A_phase_3b_randomized_controlled_trial/9945050.     

Antibody persistence 5 years after vaccination at 2 to 10 years of age with Quadrivalent MenACWY-CRM conjugate vaccine,and responses to a booster vaccination

BackgroundIn a multi-center extension study, children 2–10 years of age, initially vaccinated with one or two doses (2–5 year-olds) or one dose (6–10 year-olds) of quadrivalent meningococcal CRM₁₉₇-conjugate vaccine (MenACWY-CRM), were assessed five years later for antibody persistence and booster response using serum bactericidal assay with human complement (hSBA).MethodsChildren 7–10 and 11–15 years of age, who received MenACWY-CRM in the original study, and age-matched vaccine-naïve children, were enrolled in this extension study. After an initial blood draw, children received one dose of MenACWY-CRM as booster or primary dose, with a second blood draw 28 days later.ResultshSBA titers decreased five years after primary vaccination, but were higher than in non-vaccinated controls against serogroups C, W and Y, with substantial proportions having titers ≥8: 7–22% for A, 32–57% for C, 74–83% for W, and 48–54% for Y. Previously-vaccinated children demonstrated booster responses to revaccination against all four serogroups. Responses to primary vaccination in vaccine-naïve controls were lower and similar to primary responses observed in the original study. All vaccinations were generally well tolerated, with no safety concern raised.ConclusionsApproximately half the children vaccinated as 2–10 year-olds maintained protective antibodies against serogroups C, W and Y five years later, but fewer did against serogroup A. Declining titers five years after vaccination and robust booster responses suggest that five years may be an appropriate interval to revaccinate children, subject to epidemiology and delivery considerations.     

Short-term safety of 4CMenB vaccine during a mass meningococcal B vaccination campaign in Quebec,Canada

BackgroundTo address a high incidence of serogroup B invasive meningococcal disease (IMD-B) in the Saguenay–Lac-Saint-Jean region, Quebec, Canada, a mass vaccination campaign targeting nearly 60,000 individuals ≤20 years old was launched in May 2014. Because of the limited clinical experience with the four-component meningococcal B vaccine (4CMenB), active surveillance for adverse events following immunization (AEFI) was conducted. This paper reports 4CMenB AEFI surveillance findings.MethodsActive surveillance assessed AEFIs with acute onset within 7-days post-immunization, AEFI-associated absenteeism and medical consultations, impact of antipyretic prophylaxis and coadministration of other vaccines.ResultsBy July 17, 2015, 83% and 77% of the 59,098 individuals targeted by the campaign had received a first and a second dose of 4CMenB. The incidence of fever on days1-2 was highest in children <2 years old but only 0.6% reported a temperature ≥40^◦C. Among children <10 years old, ≥2doses of acetaminophen prophylaxis significantly reduced fever incidence on days1-2 after dose1&2. Absenteeism or a medical consultation during the 7 days following vaccination was reported by 6.2% of vaccinees post-dose1 and 9.2% post-dose2 and was most often reported in association with fever/malaise (4.2%) or injection site reactions (3.6%).ConclusionLarge-scale population-based surveillance identified a 7-day reactogenicity profile consistent with earlier clinical trials with the 4CMenB vaccine but indicating frequent AEFI-associated absenteeism and medical consultations affecting the societal cost of this vaccine. We conclude acceptable vaccine safety and risk-benefit profile overall on the short term, particularly as an intervention to address a high regional incidence of IMD-B.     

Reduced schedules of 4CMenB vaccine in infants and catch-up series in children: Immunogenicity and safety results from a randomised open-label phase 3b trial

BackgroundThis study evaluated the immunogenicity and safety of a licensed meningococcal serogroup B vaccine (4CMenB) administered alone according to reduced schedules in infants or catch-up series in children.MethodsIn this open-label, multicentre, phase 3b study (NCT01339923), infants randomised 1:1:1 received 4CMenB: 2 + 1 doses at 3½–5–11 months or 6–8–11 months of age, 3 + 1 doses at ages 2½–3½–5–11 months. Children aged 2–10 years received 2 catch-up doses administered 2 months apart. Immune responses were measured by hSBA assays against 4 strains specific for vaccine components fHbp, NadA, PorA and NHBA. Sufficiency of immune responses was defined in groups with 2 + 1 doses schedules as a lower limit ≥70% for the 97.5% confidence interval of the percentage of infants with hSBA titres ≥4, 1 month post-dose 2 for fHbp, NadA, PorA. Adverse events were collected for 7 days post-vaccination; serious adverse events (SAEs) throughout the study.Results754 infants and 404 children were enrolled. Post-primary vaccination, 98–100% of infants across all groups developed hSBA titres ≥4 for fHbp, NadA, PorA, and 48–77% for NHBA. Sufficiency of immune responses in infants receiving 2 + 1 schedules was demonstrated for fHbp, NadA, PorA after 2 doses of 4CMenB, as pre-specified criteria were met. Following receipt of 2 catch-up doses, 95–99% of children developed hSBA titres ≥4 for 4CMenB components. Similar safety profiles were observed across groups. A total of 45 SAEs were reported, 3 of which were related to vaccination.ConclusionReduced infant schedules and catch-up series in children were immunogenic and safe, having the potential to widen 4CMenB vaccine coverage.FundingGlaxoSmithKline Biologicals SA.     

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.     

Breadth of coverage against a panel of 110 invasive disease isolates,immunogenicity and safety for 2 and 3 doses of an investigational MenABCWY vaccine in US adolescents – Results from a randomized,controlled, observer-blind phase II study

BackgroundNeisseria meningitidis serogroups A, B, C, W and Y cause most meningococcal disease worldwide. An investigational MenABCWY vaccine combining serogroup B antigens and a meningococcal ACWY CRM₁₉₇-glycoconjugate vaccine (MenACWY-CRM) could provide protection against all 5 serogroups. Complement mediated bactericidal activity induced by MenABCWY was tested against a panel of 110 randomly-selected serogroup B strains causing invasive disease in the US to evaluate the vaccine’s breadth of coverage (BoC).MethodsWe conducted this observer-blind study (NCT02140762) and its extension (NCT02285777) in 8 centers in the US. Adolescents aged 10–18 years were randomized (1:1) to receive either 3 MenABCWY doses (MenABCWY group), on a 0, 2, 6-month (M) schedule or a single MenACWY-CRM dose at M2 and placebo at 0,6-M (Control group). MenABCWY BoC was calculated as (1 − relative risk) × 100 (relative risk = ratio between the percentage of samples seronegative at 1:4 dilution against the selected strains in the MenABCWY vs Control group). BoC was determined at 1 M and 4 M after 2 and 3 doses, using an endogenous complement serum bactericidal assay. Immunogenicity and safety were assessed.Results301 and 189 adolescents were vaccinated in the parent and extension study, respectively. At 1 M post-vaccination, the BoC of MenABCWY across the 110 serogroup B strains was 67% (95%CI: 65–69) after 2 doses and 71% (95%CI: 69–73) after 3 doses. BoC decreased to 44% (95%CI: 41–47) and 51% (95%CI: 48–55) at 4 M after 2 and 3 MenABCWY doses, respectively. Robust immune responses to antigen-specific test strains for each serogroup were observed at all timepoints in the MenABCWY group. No reactogenicity or safety concerns arose during the study.ConclusionTwo or 3 doses of MenABCWY showed similar BoC against the panel of invasive US serogroup B isolates and comparable immunogenicity against the antigen-specific test strains, with no safety concerns identified.     

Immunogenicity,safety, and tolerability of the meningococcal serogroup B bivalent rLP2086 vaccine in adult laboratory workers

BackgroundThe bivalent rLP2086 vaccine is approved in the United States to prevent meningococcal disease caused by Neisseria meningitidis serogroup B (MnB) in individuals aged 10–25 years. The immunogenicity and safety of bivalent rLP2086 were evaluated in microbiologists 24–62 years old who handle MnB.MethodsSeven subjects vaccinated at 0, 2, and 6 months had functional antibodies measured before vaccination and 1 month after each dose by serum bactericidal assays using human complement (hSBAs) and 4 vaccine-heterologous MnB test strains.ResultsSix subjects qualified for analysis. All demonstrated hSBA titers ≥the lower limit of quantitation (LLOQ) against 3 of 4 strains; 3 subjects achieved titers ≥LLOQ for the fourth. Safety-related events following vaccination were generally mild to moderate in severity.ConclusionsThree doses of bivalent rLP2086 were generally well tolerated in laboratory personnel and elicited protective functional immune responses reflective of broad coverage against MnB disease.     

Vaccination against serogroup B Neisseria meningitidis: Perceptions and attitudes of parents

BackgroundA vaccine against serogroup B Neisseria meningitidis, major cause of bacterial meningitis in children and adults, has recently been developed. In a context of an increasing parental mistrust against vaccinations, understanding the reason for their choices is crucial in order to improve immunization coverage. Our study aimed at evaluating parental attitudes and perceptions towards serogroup B meningococcal invasive disease vaccination.MethodsA prospective observational study was conducted in different French independent-practice medical offices (general practitioners and paediatricians) and nurseries between May 1 and December 31, 2013, using a questionnaire distributed in electronic and paper forms to parents having at least one child between the ages of 2 months and 16 years old.Results1270 parents were included, of whom 671 (52.8%) spontaneously stated to be in favour of this vaccination. Their choice was mainly justified by the severity of the disease (63.8%) and the desire to protect their child (51.7%). In multivariate analysis, the young age of parents (OR 0.949 per additional year; p < 10⁻³), the history of vaccination against serogroup C meningococcal invasive diseases (OR 6.755; p < 10⁻³), and the prior knowledge of the vaccine (OR 2.081; p = 0.001) were associated with vaccination acceptance. The main reasons for refusal were the lack of hindsight on this new vaccine (50.6%) and the fear of side effects (45.5%). After objective information on the disease and the vaccine, only 6.3% of the entire responding population would refuse to consider vaccination.ConclusionsThe spontaneous acceptance rate of vaccination against serogroup B meningococcal invasive disease is insufficient. However, after objective information by their physician or public health authorities, only a few parents would in the end be completely resistant.     

Immunogenicity and safety of the quadrivalent meningococcal vaccine MenACWY-TT co-administered with a combined diphtheria-tetanus-acellular pertussis vaccine versus their separate administration in adolescents and young adults: A phase III,randomized study

BackgroundThis study evaluated the immunogenicity and safety of quadrivalent meningococcal conjugate vaccine using tetanus (T) toxoid as carrier protein (MenACWY-TT) co-administered with combined diphtheria-tetanus-acellular pertussis vaccine (Tdap) versus their separate administration in adolescents and young adults.MethodsIn this phase III, randomized, partially-blind study (NCT01767376), healthy 11–25-year-olds (N = 660) were randomized (1:1:1) to receive MenACWY-TT and Tdap at Month 0 (Co-ad group), MenACWY-TT at Month 0 and Tdap at Month 1 (ACWY_Tdap group) or Tdap at Month 0 and MenACWY-TT at Month 1 (Tdap_ACWY group). Immune responses to MenACWY-TT were measured by serum bactericidal assay using rabbit complement (rSBA). Anti-diphtheria (D), anti-tetanus (T), anti-pertussis toxin (PT), anti-filamentous hemagglutinin (FHA) and anti-pertactin (PRN) antibody concentrations were assessed using enzyme-linked immunosorbent assays. Non-inferiority of immunogenicity was assessed using pre-defined clinical criteria. Safety was also evaluated.ResultsNon-inferiority of immunogenicity of MenACWY-TT and Tdap when co-administered versus their separate administration was demonstrated in terms of rSBA geometric mean titers (GMTs) for 4 meningococcal serogroups and of the percentage of participants with antibody concentrations >1 IU/ml for D and T. Among the pertussis antigens, non-inferiority criteria for geometric mean concentrations (GMCs) were reached for PT, but not met for FHA and PRN. Across all groups, ≥93.2% of participants had vaccine responses to each meningococcal serogroup, ≥99.1% were seroprotected against T and D, and ≥85.5% had booster responses to each pertussis antigen. Robust increases in antibody GMTs/GMCs were observed for all antigens between pre-and post-vaccination. Both vaccines had clinically acceptable safety profiles.ConclusionImmune responses to MenACWY-TT and to the T and D antigens from Tdap were not impacted by their co-administration. The lower antibody concentrations observed against the pertussis components may be of limited clinical relevance since robust anti-pertussis booster responses were observed. This study supports concurrent administration of the 2 vaccines in adolescents.     

Decennial administration in young adults of a reduced-antigen content diphtheria,tetanus, acellular pertussis vaccine containing two different concentrations of aluminium

BackgroundRegular booster vaccination might be necessary throughout life to protect against pertussis infection. Nevertheless the duration of protection after booster vaccination remains unclear. In this study, antibody persistence up to 10 years after previous vaccination of adolescents (N = 478) with combined reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine (dTpa, Boostrix™, GlaxoSmithKline Belgium) containing 0.5 mg, 0.3 mg or 0.133 mg of aluminium was assessed. The immunogenicity, reactogenicity and safety of a decennial booster dTpa dose were also investigated.MethodsYoung adults vaccinated as adolescents in the initial booster study were invited to participate in an assessment of antibody persistence at years 8.5 and 10, and to receive a dTpa booster dose at year 10 with immunogenicity assessment one month later. Those who originally received the 0.5 mg or 0.3 mg formulations received the same vaccine at year 10. Those in the 0.133 mg group received the 0.5 mg formulation. Reactogenicity and safety endpoints were captured until 30 days after booster vaccination.ResultsPrior to the decennial booster at year 8.5 and year 10, all participants had seroprotective antibodies for diphtheria (ELISA or neutralisation assay) and tetanus. At least 77.8% were seropositive for anti-pertussis toxin (PT) antibodies at year 8.5 and 82.8% at year 10. All participants were seropositive for antibodies for filamentous haemagglutinin and pertactin at both time points. The decennial booster dose induced robust increases in antibody GMCs to all antigens. The post-booster anti-PT geometric mean concentration was 82.5 EL.U/ml (95%CI 67.0–101.6) and 124.0 (103.5–148.5) in the 0.3 mg and 0.5 mg groups, respectively. The reactogenicity and safety profile of the decennial booster dose was consistent with the known safety profile of dTpa. No serious adverse events were reported.ConclusionsDecennial booster vaccination with either of the two licensed formulations of dTpa was highly immunogenic and well tolerated in young adults. Either formulation could be confidently used as a decennial booster.This study is registered at www.clinicaltrials.gov NCT01147900     

A native outer membrane vesicle vaccine confers protection against meningococcal colonization in human CEACAM1 transgenic mice

BackgroundThe effect of protein-based meningococcal vaccines on prevention of nasopharyngeal colonization has been difficult to investigate experimentally because a reliable animal colonization model did not exist.MethodsHuman CEACAM1 transgenic mice, which can be colonized by meningococci, were immunized IP with one of two meningococcal native outer membrane vesicle (NOMV) vaccines prepared from mutants with attenuated endotoxin (lpxL1 knockout) and over-expressed sub-family B Factor H-binding proteins (FHbp). Animals were challenged intranasally two weeks after the third dose with wild-type strain H44/76, or were treated IP with anti-NOMV serum before and during the bacterial challenge.ResultsThe NOMV-1 vaccine, prepared from the serogroup B H44/76 mutant, elicited ∼40-fold higher serum bactericidal antibody titers against the wild-type H44/76 challenge strain than the NOMV-2 vaccine prepared from a heterologous serogroup W mutant strain with different PorA and FHbp amino acid sequence variants. Compared to aluminum hydroxide-immunized control mice, the efficacy for prevention of any H44/76 colonization was 93% (95% confidence interval, 52–99, P < 0.0001) for the NOMV-1 vaccine, and 19% (−3–36, P = 0.23) for NOMV-2. NOMV-2-vaccinated mice had a 5.6-fold decrease in geometric mean CFU of bacteria per animal in tracheal washes compared to control mice (P = 0.007). The efficacy of passive administration of serum from NOMV-1-vaccinated mice to immunologically naïve mice against colonization was 44% (17–61; P = 0.002).ConclusionsBoth NOMV vaccines protected against meningococcal colonization but there was greater protection by the NOMV-1 vaccine with antigens matched with the challenge strain. Meningococcal vaccines that target protein antigens have potential to decrease colonization.     

Safety and immunogenicity of a quadrivalent intradermal influenza vaccine in adults

BackgroundAn intradermal (ID) trivalent split-virion influenza vaccine (IIV3-ID) (Fluzone^® Intradermal, Sanofi Pasteur, Swiftwater, PA) has been available in the US since the 2011/2012 influenza season for adults aged 18–64 years. This study examined whether adding a second B-lineage strain affects immunogenicity and safety.MethodsThis randomized, double-blind, multicentre trial evaluated the immunogenicity and safety of an intradermal quadrivalent split-virion influenza vaccine (IIV4-ID) in adults 18–64 years of age in the US during the 2012–2013 influenza season. Participants were randomized 2:1:1 to receive a single injection of IIV4-ID, licensed IIV3-ID, or an investigational IIV3-ID containing the alternate B-lineage strain. Haemagglutination inhibition antibody titres were assessed in two-thirds of participants before vaccination and 28 days after vaccination.Results1672 participants were vaccinated with IIV4-ID, 837 with licensed IIV3-ID, and 846 with an investigational IIV3-ID. For all four vaccine strains, antibody responses to IIV4-ID were statistically non-inferior to the response to the IIV3-ID vaccines containing the matched strains. For both B strains, post-vaccination antibody responses to IIV4-ID were statistically superior to the responses to IIV3-ID lacking the corresponding B strain. Adverse events were similar for IIV4-ID and IIV3-ID. The most commonly reported solicited reactions were pain, pruritus, myalgia, headache, and malaise; and most were grade 1 or 2 and appeared and resolved within 3 days of vaccination. IIV4-ID was statistically non-inferior to the two pooled IIV3-ID vaccines for the proportions of participants with at least one grade 2 or 3 systemic reaction.ConclusionsAntibody responses to the IIV4-ID were non-inferior to IIV3-ID for the A and matched B strains and superior for the unmatched B strains. IIV4-ID was well tolerated without any safety concerns. IIV4-ID may help address an unmet need due to mismatched B strains in previous influenza vaccines.     

Immunogenicity and safety of measles-mumps-rubella vaccine at two different potency levels administered to healthy children aged 12–15 months: A phase III,randomized, non-inferiority trial

BackgroundThe potency of live viral vaccines decreases over time. We compared the immunogenicity and safety of GSK measles-mumps-rubella vaccine (MMR-RIT) formulations at two different potencies with that of the commercially-available MMR II formulation.MethodsIn this phase III observer-blind clinical study (NCT01681992), 4516 healthy children aged 12–15 months were randomized (1:1:1 ratio) to receive one dose of MMR-RIT at the minimum potency used for this study (MMR-RIT-Min) or MMR-RIT at the second lowest potency used for this study (MMR-RIT-Med), or control MMR II vaccine. A second dose (MMR-RIT or MMR II) was administered 42 days after the first. The study had 10 co-primary objectives to evaluate MMR-RIT versus MMR II immunogenicity via a hierarchical procedure. Anti-measles and anti-rubella antibodies were measured by ELISA and anti-mumps antibodies by ELISA and unenhanced plaque reduction neutralization test (PRNT).ResultsEach formulation induced immune responses to all vaccine antigens after each MMR dose. While the primary objectives for MMR-RIT-Min were not met, MMR-RIT-Med induced immune responses as measured by ELISA against the three vaccine antigens that met pre-specified non-inferiority criteria. The immune response following MMR-RIT-Med against mumps measured by PRNT failed the non-inferiority criterion for seroresponse rate: the 97.5% confidence interval lower limit (−10.94%) was beyond the pre-defined limit of −10%. Immune responses were comparable among groups post-dose 2. No safety concerns were identified, and MMR-RIT and MMR II vaccines had similar reactogenicity and safety profiles.ConclusionsOne dose of MMR-RIT formulation with lower potency (MMR-RIT-Med) induced a non-inferior immune response compared to commercial MMR II vaccine, measured by ELISA in one-year-old children. Non-inferiority was not demonstrated in terms of immune response against mumps virus measured by unenhanced PRNT, although the difference was of uncertain clinical relevance. After the second dose, immune responses were comparable among the MMR-RIT and MMR II groups.     

Quality,immunogenicity and stability of meningococcal serogroup ACWY-CRM197, DT and TT glycoconjugate vaccines

A physicochemical and immunological study of the stability of three different meningococcal (Men) ACWY conjugate vaccines was performed to evaluate any patterns of serogroup oligo- or polysaccharide-specific or carrier protein-specific stability that would affect immunogenicity. Critical quality and stability-indicating characteristics were measured, with the study supporting the suitability of both HPLC-SEC and HPAEC-PAD methods to detect changes following inappropriate vaccine storage. All three final products, ACWY-CRM₁₉₇, -DT and -TT conjugate vaccines had expected quality indicator values and similar immunogenicity in a mouse model (anti-PS IgG and rSBA) when stored at +2–8 °C. When stored at ≥+37 °C, all conjugated carrier proteins and serogroup saccharides were affected. Direct correlations were observed between the depolymerization of the MenA saccharide as evidenced by a size-reduction in the MenA conjugates (CRM₁₉₇, DT and TT) and their immunogenicity. MenA was the most labile serogroup, followed by MenC; then MenW and Y, which were similar. At high temperatures, the conjugated carrier proteins were prone to unfolding and/or aggregation. The anti-MenC IgG responses of the multivalent conjugate vaccines in mice were equivalent to those observed in monovalent MenC conjugate vaccines, and were independent of the carrier protein. For any newly developing MenACWY saccharide-protein conjugate vaccines, a key recommendation would be to consider the lyophilization of final product to prevent deleterious degradation that would affect immunogenicity.     

Immunogenicity and safety of an AS03-adjuvanted H5N1 pandemic influenza vaccine in Korean adults: A phase IV,randomized, open-label,controlled study

BackgroundAS03-adjuvanted H5N1 pandemic influenza vaccines have been assessed in an extensive clinical development program conducted in North America, Europe, and Asia including children from 6 months of age, adults, and elderly adults. We evaluated AS03-H5N1 in Korean adults 18 through 60 years of age.MethodsThis Phase IV, randomized, study was conducted to assess the immunogenicity, reactogenicity, and safety of two doses (3.75 μg of hemagglutinin antigen) of A/Indonesia/5/2005 (H5N1) adjuvanted with AS03 given 21 days apart in Korean adults. Antibody responses were assessed using hemagglutination-inhibition (HI) assays against the vaccine strain and a vaccine-heterologous strain (A/Vietnam/1194/2004) 21 days after the second dose. A control group (safety) received a licensed seasonal inactivated trivalent influenza vaccine (TIV). Reactogenicity was assessed for 7 days after each vaccination, and unsolicited adverse events were assessed for 182 days following vaccination in both study groups (NCT01730378).ResultsAS03-H5N1 was immunogenic and elicited robust HI antibody responses with seroconversion rates of 100% for the vaccine strain and 69.1% for the heterologous strain (N = 81). HI antibody responses fulfilled the European licensure criteria for immunogenicity (primary endpoint). The incidence of local and systemic solicited adverse events (reactogenicity) was higher with AS03-H5N1 than TIV. There was no apparent difference in the rate of unsolicited adverse events in the AS03-H5N1 and TIV groups.ConclusionThe results indicate that AS03-H5N1 vaccine is immunogenic with reactogenicity and safety findings that are consistent with the established profile of AS03-H5N1 vaccine.     

Distribution of Bexsero® Antigen Sequence Types (BASTs) in invasive meningococcal disease isolates: Implications for immunisation

Serogroup B is the only major disease-associated capsular group of Neisseria meningitidis for which no protein-polysaccharide conjugate vaccine is available. This has led to the development of multi-component protein-based vaccines that target serogroup B invasive meningococcal disease (IMD), including Bexsero®, which was implemented for UK infants in 2015, and Trumenba®. Given the diversity of meningococcal protein antigens, post-implementation surveillance of IMD isolates, including characterisation of vaccine antigens, is essential for assessing the effectiveness of such vaccines. Whole genome sequencing (WGS), as realised in the Meningitis Research Foundation Meningococcus Genome Library (MRF-MGL), provides a rapid, comprehensive, and cost-effective approach to this. To facilitate the surveillance of the antigen targets included in Bexsero® (fHbp, PorA, NHBA and NadA) for protective immunity, a Bexsero® Antigen Sequence Type (BAST) scheme, based on deduced peptide sequence variants, was implemented in the PubMLST.org/neisseria database, which includes the MRF-MGL and other isolate collections. This scheme enabled the characterisation of vaccine antigen variants and here the invasive meningococci isolated in Great Britain and Ireland in the epidemiological years 2010/11 to 2013/14 are analysed. Many unique BASTs (647) were present, but nine of these accounted for 39% (775/1966) of isolates, with some temporal and geographic differences in BAST distribution. BASTs were strongly associated with other characteristics, such as serogroup and clonal complex (cc), and a significant increase in BAST-2 was associated with increased prevalence of serogroup W clonal complex 11 meningococci. Potential coverage was assessed by the examination of the antigen peptide sequences present in the vaccine and epidemiological dataset. There were 22.8–30.8% exact peptide matches to Bexsero® components and predicted coverage of 66.1%, based on genotype-phenotype modelling for 63.7% of serogroup B isolates from 2010/14 in UK and Ireland. While there are many caveats to this estimate, it lies within the range of other published estimates.     

Immunogenicity and safety of a quadrivalent inactivated influenza vaccine compared with two trivalent inactivated influenza vaccines containing alternate B strains in adults: A phase 3, randomized noninferiority study

BackgroundVaccination is the most effective means of influenza prevention. Efficacy of trivalent vaccines may be enhanced by including both B strain lineages. This phase 3, double-blind study assessed the immunogenicity and safety/tolerability of a quadrivalent inactivated influenza vaccine (IIV4) versus the United States (US)-licensed 2014–2015 trivalent inactivated influenza vaccine (IIV3-Yamagata [IIV3-YAM]; Afluria) and IIV3 containing the alternate Victoria B strain (IIV3-VIC) in adults ≥18 years.MethodsParticipants (n = 3484) were randomized 2:1:1 and stratified by age to receive IIV4 (n = 1741), IIV3-YAM (n = 871), or IIV3-VIC (n = 872). The primary objective was to demonstrate noninferiority of the immunological response to IIV4 versus IIV3-YAM and IIV3-VIC. Noninferiority was assessed by hemagglutination inhibition geometric mean titer (GMT) ratio (IIV3/IIV4; upper bound of two-sided 95% confidence interval [CI] ≤ 1.5) and seroconversion rate (SCR) difference (IIV3 – IIV4; upper bound of two-sided 95% CI ≤ 10%) for vaccine strains. Solicited local and systemic adverse events (AEs) were assessed for 7 days postvaccination, AEs recorded for 28 days postvaccination, and serious AEs for 6 months postvaccination.ResultsIIV4 elicited a noninferior immune response for matched strains, and superior response for unmatched B strains not contained in IIV3 comparators. Adjusted GMT ratios (95% CI) for A/H1N1, A/H3N2, B/YAM, and B/VIC strains were 0.93 (0.88, 0.99), 0.93 (0.88, 0.98), 0.87 (IIV3-YAM; 0.82, 0.93), and 0.95 (IIV3-VIC; 0.88, 1.03), respectively. Corresponding values for SCR differences (95% CI) were −1.1 (−4.5, 2.3), −1.7 (−5.0, 1.7), −3.2 (IIV3-YAM; −7.4, 0.9), and −1.6 (IIV3-VIC; −5.8, 2.5). AEs were generally mild and experienced by 52.9% of participants. Serious AEs were reported with a slightly higher frequency with IIV4 (2.3%) versus IIV3-YAM (1.6%) and IIV3-VIC (1.5%).ConclusionsIIV4 demonstrated immunological noninferiority to the US-licensed IIV3, and superiority for unmatched B strains not contained in IIV3 comparators. Safety/tolerability profiles were similar across vaccine groups.Funding: Seqirus; Clinicaltrials.gov: NCT02214225.     

The effectiveness of influenza vaccination in preventing hospitalisation in children in Western Australia

BackgroundThere is increasing evidence demonstrating influenza vaccine effectiveness (VE) in the prevention of influenza in children, including the very young. Data demonstrating the effectiveness against severe disease, including hospitalisation, are limited. We aimed to determine the VE of the southern hemisphere trivalent inactivated influenza vaccine (TIV) in preventing laboratory-confirmed influenza-associated hospitalisation in children.Patients and MethodsLaboratory records were used to identify children with confirmed influenza hospitalised (i.e., cases) during a 5 year period (2008, 2010–2013) at the only tertiary paediatric facility in Western Australia. Cases and time, age and ward matched controls were retrospectively reviewed to determine risk factors, vaccination status and outcome. Adjusted odds ratios and VE estimates were derived using conditional logistic regression models.ResultsThree hundred and eighty five cases were identified (Influenza A, 64.9%; Influenza B, 35.1%). Influenza-like illness and pneumonia were the most frequent presentation (74.5% and 23.9%, respectively). The median length of stay was 2 days (Interquartile range 1–4 days). Twenty children (5.2%) required admission to the intensive care unit. Vaccine uptake in cases and controls was low (4.9% and 8.5%, respectively). Three hundred and six case-control pairs were included in the VE analysis, of which 19 pairs were informative with discrepant vaccination status. VE (fully vaccinated vs. unvaccinated) was estimated to be 62.3% (95% CI: −6.6%, 86.7%).ConclusionIn this study, the point estimate for the effectiveness of TIV in preventing influenza-associated hospitalisation in children was similar to that reported for emergency or outpatient attended, laboratory-confirmed influenza, yet confidence intervals were wide. Vaccine uptake remains low. Studies, enroling larger numbers of children, ideally with higher vaccine uptake, are needed to provide additional evidence on TIV protection against influenza hospitalisation in children.     

Immunogenicity and safety of double versus standard dose of the seasonal influenza vaccine in solid-organ transplant recipients: A randomized controlled trial

BackgroundThe use of vaccines with higher doses of antigen is an attractive strategy to improve the immunogenicity of influenza vaccination in transplant recipients. However, the effect of vaccination with a double-dose (DD) containing 30 µg of antigen in this population remains unknown.MethodsWe performed a randomized controlled trial to compare the immunogenicity and safety of DD (30 µg) vs. standard dose (SD, 15 µg) of a trivalent inactivated influenza vaccine in kidney and liver transplant recipients. Immunogenicity was assessed by hemagglutination-inhibition assay. Vaccine response was defined as seroconversion to at least one viral strain 2 weeks after vaccination and seroprotection as a titer ≥40.ResultsSixty-three kidney and 16 liver transplant recipients were enrolled. Forty patients received the DD and 39 the SD vaccine. Overall, 40% of patients in the DD compared to 26% in the SD group (P = 0.174) responded to vaccine. In the DD arm, more patients were seroprotected to all viral strains after vaccination (88% vs 69%, P = 0.048). Post vaccination geometric mean titers of antibodies were 131.9 vs. 89.7 (P = 0.187) for H1N1, 185.4 vs. 138.7 (P = 0.182) for H3N2, and 96.6 vs. 68.8 (P = 0.081) for influenza B with the DD vs. SD. In both groups, most of the adverse events were mild and no vaccine-related severe adverse events were observed.ConclusionDouble-dose influenza vaccine is safe and may increase antibody response in transplant recipients. In this population, DD vaccination could be an alternative when high-dose vaccine is not available. NCT02746783.