Sustained antibody persistence for at least 15 years after a booster vaccination against tick-borne encephalitis following different primary vaccination schedules: Third 5-year follow-up.

BACKGROUND: Vaccination is the best mode of protection against tick-borne encephalitis (TBE) and its sequelae. The duration of protection and the optimal interval of repeat booster doses are still debated. The current study evaluated the persistence of the antibody response 11-15 years after a first booster vaccination following different primary vaccination schedules with a TBE vaccine (Encepur Adults, manufactured by Bavarian Nordic, previously by GSK). METHODS: This phase IV, open-label, mono-centric extension study enrolled adults who had received (at ≥ 12 years of age) primary vaccination with one of three randomly assigned TBE vaccine schedules (rapid [group R], conventional [group C], or accelerated conventional schedule [group A]) followed by a booster dose 3 years later. The antibody response was measured annually from 11 to 15 years post-booster using a TBE virus neutralization test (NT). An NT titer of ≥ 10 was considered as a clinically meaningful threshold and surrogate for protection. RESULTS: In total, 194 participants were enrolled and included in the per-protocol set; 188 completed the study. The percentage of participants with an NT titer ≥ 10 was 100% in group R and 99.0% in group A at all visits and ranged from 100% (year 11) to 95.8% (year 15) in group C. NT geometric mean titers were similar in the three study groups (181-267 in group R, 142-227 in group C, 141-209 in group A). NT geometric mean titers also remained high among participants ≥ 50 years old (98-206) and ≥ 60 years old (91-191) across study groups and time points. CONCLUSIONS: This study showed neutralizing antibody persistence for at least 15 years after a first booster dose of the Encepur Adults TBE vaccine in all age groups evaluated, regardless of which primary vaccination schedule was given to adolescents or adults. Trialregistry: ClinicalTrials.gov: NCT03294135.

Fully Liquid MenACWY-CRM Vaccine: Results from an Integrated Safety Analysis.

INTRODUCTION: The currently licensed quadrivalent MenACWY-CRM conjugate vaccine presentation consists of two vials (lyophilized MenA and liquid MenCWY) to be reconstituted before injection. A new fully liquid, single-vial formulation has been developed to simplify administration and prevent reconstitution errors. We present pooled safety data from two randomized, controlled, observer-blind phase 2b clinical trials, in which the fully liquid presentation was compared with the licensed presentation. METHODS: This is a post hoc analysis of two studies, in which safety data from participants aged 10-40 years who received one dose of either liquid MenACWY-CRM (1337 participants; MenACWY liquid group) or licensed MenACWY-CRM (1332 participants; MenACWY licensed group) were pooled. Frequencies were calculated for solicited adverse events (AEs) during 7 days post-vaccination and unsolicited AEs, including medically attended AEs and serious AEs (SAEs), during the 6-month safety follow-up period. Analysis results are presented by vaccine group, overall and by age category (10-17 and 18-40 years). RESULTS: Overall, AEs solicited for collection during the first 7 days after vaccination were reported by similar percentages of participants (69.2%, MenACWY liquid; 68.2%, MenACWY licensed), and were generally mild/moderate in intensity. Solicited local AEs were reported by 46.0% of the MenACWY liquid group and 43.5% of the MenACWY licensed group and solicited systemic AEs by 55.2 and 54.1%, respectively. During the 6-month post-vaccination period, unsolicited AEs were reported by 32.2 and 31.2% of the MenACWY liquid group and MenACWY licensed group, respectively, and medically attended AEs by 18.6 and 17.3%, respectively. Overall, 14 participants in each group (1.0 and 1.1%, respectively) reported SAEs, none of which was considered vaccine-related by the investigator. The safety profiles of both MenACWY-CRM presentations were similar for each age group and overall. CONCLUSIONS: This pooled analysis shows the safety profile of fully liquid MenACWY-CRM is comparable with that of the currently licensed vaccine presentation. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT03652610 (August 29, 2018), NCT03433482 (14 February 2018).

Non-typeable Haemophilus influenzae-Moraxella catarrhalis vaccine for the prevention of exacerbations in chronic obstructive pulmonary disease: a multicentre, randomised, placebo-controlled, observer-blinded, proof-of-concept, phase 2b trial.

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are associated with changes in the sputum microbiome, including an increased prevalence of pathogenic bacteria. Vaccination against the most frequent bacteria identified in AECOPD might reduce exacerbation frequency. We assessed the efficacy, safety, and immunogenicity of a candidate vaccine containing surface proteins from non-typeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis (Mcat) in patients with COPD. METHODS: This multicentre, randomised, observer-blinded, placebo-controlled, proof-of-concept, phase 2b trial recruited patients with stable COPD, moderate-to-very severe airflow limitation (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage 2, 3, or 4), at 67 clinical sites in Belgium, Canada, France, Germany, Italy, Spain, UK, and USA. Eligible patients were aged 40-80 years and had a history of at least one moderate or severe exacerbation in the previous year. Patients were allocated (1:1) using a minimisation algorithm to receive two intramuscular injections of NTHi-Mcat vaccine or placebo 60 days apart, in addition to standard care. The allocation algorithm considered age category, number of previous exacerbations, COPD severity at study entry, and country as minimisation factors, to guarantee treatment balance within each factor. Vaccine recipients and those responsible for evaluating study endpoints were masked to group allocation. In the analysis of efficacy, the primary outcome was the rate of any moderate or severe AECOPD occurring within a 1-year period, starting 1 month after the second dose in patients who received two vaccine doses (modified total vaccinated cohort). Safety was assessed in the total vaccinated cohort. The trial is registered with ClinicalTrials.gov, number NCT03281876, and is complete. FINDINGS: Between Nov 27, 2017, and Nov 30, 2018, 606 adults were enrolled and included in the total vaccinated cohort (304 in the NTHi-Mcat vaccine group, 302 in the placebo group); 571 received two doses and were included in the primary efficacy analysis (279 in the NTHi-Mcat vaccine group, 292 in the placebo group). 23 participants dropped-out in the NTHi-Mcat vaccine group and 39 in the placebo group; this included 4 patients in the NTHi-Mcat vaccine group and 15 in the placebo group who withdrew from the study because of an adverse event. The primary analysis included 340 exacerbations (in follow-up time 102 123 days) in the NTHi-Mcat vaccine group and 333 (in 104 443 days) in the placebo group, with a yearly rate of moderate or severe AECOPD of 1·22 in the NTHi-Mcat vaccine group and 1·17 in the placebo group, with vaccine efficacy in reducing the yearly rate of moderate or severe AECOPD estimated to be zero (vaccine efficacy point estimate 2·26% [87% CI -18·27 to 11·58]; p=0·82). Solicited local adverse events were more frequent in the NTHi-Mcat vaccine group (216 [72%] of 301 patients) than with placebo (34 [11%] of 299 patients), and the frequency of solicited general adverse events was similar between groups (239 [79%] of 301 vs 235 [79%] of 299 patients). There was one death in the NTHi-Mcat vaccine group (acute respiratory failure, not related to vaccination) and ten in the placebo group (seven due in part to COPD or respiratory failure). There were 158 serious adverse events (89 [29%] of 304 patients) in the NTHi-Mcat vaccine group, not related to vaccination, and 214 (99 [33%] of 302 patients) in the placebo group. INTERPRETATION: NTHi-Mcat vaccine administered to patients with COPD did not show efficacy in reducing the yearly rate of moderate or severe exacerbations. No safety concerns were identified. FUNDING: GlaxoSmithKline Biologicals SA.

Immunological non-inferiority of a new fully liquid presentation of the MenACWY-CRM vaccine to the licensed vaccine: results from a randomized, controlled, observer-blind study in adolescents and young adults.

A fully liquid MenACWY-CRM vaccine presentation has been developed, modifying the meningococcal serogroup A (MenA) component from lyophilized to liquid. The safety and immunogenicity of the liquid presentation at the end of the intended shelf-life (aged for 24 or 30 months) were compared to the licensed lyophilized/liquid presentation. This multicenter, randomized (1:1), observer-blind, phase 2b study (NCT03433482) enrolled adolescents and young adults (age 10-40 years). In part 1, 844 participants received one dose of liquid presentation stored for approximately 24 months or licensed presentation. In part 2, 846 participants received one dose of liquid presentation stored for approximately 30 months or licensed presentation. After storage, the MenA free saccharide (FS) level was approximately 25% and O-acetylation was approximately 45%. The primary objective was to demonstrate non-inferiority of the liquid presentation to licensed presentation, as measured by human serum bactericidal assay (hSBA) geometric mean titers (GMTs) against MenA, 1-month post-vaccination. Immune responses against each vaccine serogroup were similar between groups. Between-group ratios of hSBA GMTs for MenA were 1.21 (part 1) and 1.11 (part 2), with two-sided 95% confidence interval lower limits (0.94 and 0.87, respectively) greater than the prespecified non-inferiority margin (0.5), thus meeting the primary study objective. No safety concerns were identified. Despite reduced O-acetylation of MenA and increased FS content, serogroup-specific immune responses induced by the fully liquid presentation were similar to those induced by the licensed MenACWY-CRM vaccine, with non-inferior anti-MenA responses. The safety profiles of the vaccine presentations were similar.

A new fully liquid presentation of MenACWY-CRM conjugate vaccine: Results from a multicentre, randomised, controlled, observer-blind study.

BACKGROUND: The currently licensed quadrivalent MenACWY-CRM conjugate vaccine presentation consists of two vials (lyophilised MenA and liquid MenCWY) to be reconstituted before injection. A new fully liquid formulation in a single vial has been developed to further improve the vaccine presentation. Since the MenA structure is subject to hydrolytic degradation, this study was conducted to compare the immunogenicity and safety of the investigational MenACWY-CRM liquid vaccine with the licensed vaccine. METHODS: In this multicentre, randomised, controlled, observer-blind, phase 2b study, 979 healthy adults were administered a single dose of MenACWY-CRM liquid presentation or the currently licensed MenACWY-CRM vaccine. MenA free saccharide generation was accelerated to approximately 30% in the liquid presentation and MenA polysaccharide O-acetylation was reduced to approximately 40%, according to a controlled procedure. Immunological non-inferiority of the MenACWY-CRM liquid to the licensed vaccine, as measured by human serum bactericidal assay (hSBA) geometric mean titres (GMTs) against MenA 1 month post-vaccination, was the primary study objective. Safety assessment was among the secondary objectives. RESULTS: Immune responses against each serogroup were similar between the two vaccine groups and was non-inferior for MenA. Adjusted hSBA GMTs for MenA were 185.16 and 211.33 for the MenACWY-CRM liquid presentation and currently licensed vaccine presentation, respectively. The between-group ratio of hSBA GMTs for MenA was 0.88, with a two-sided 95% confidence interval lower limit of 0.64, greater than the prespecified non-inferiority margin of 0.5, thus meeting the primary study objective. Both vaccines were well tolerated. No serious adverse events were considered related to vaccination. CONCLUSIONS: The levels of MenA free saccharide and polysaccharide O-acetylation did not affect the immunogenicity of the fully liquid presentation, which was demonstrated to be non-inferior to the immunogenicity of the currently licensed MenACWY-CRM vaccine against MenA. The immunogenicity, reactogenicity and safety profiles of the two vaccine presentations were similar.

Clinical efficacy of cell culture­derived and egg­derived inactivated subunit influenza vaccines in healthy adults.

BACKGROUND: More efficient methods are needed to manufacture influenza vaccines. This trial compared the efficacy of cell culture-derived influenza vaccine (CCIV) and egg-derived trivalent inactivated vaccine (TIV) with placebo against laboratory-confirmed influenza illness in healthy adults in the United States, Finland, and Poland during the 2007-2008 influenza season. METHODS: A total of 11,404 study participants aged 18-49 years were randomized equally to receive CCIV (Optaflu; n = 3828), TIV (Agrippal; n = 3676), or placebo (n = 3900). Each participant was observed during a 6-month study surveillance period. Nasal and throat swabs for virus isolation and characterization were collected from all patients with influenza-like illness. Vaccine immunogenicity was evaluated in a subset of 1045 participants. RESULTS: Efficacy of CCIV and TIV against vaccine-like (83.8% [1-sided 97.5% confidence interval [CI] lower limit, 61.0%] and 78.4% [1-sided 97.5% CI lower limit, 52.1%], respectively) and all circulating influenza virus strains (69.5% [1-sided 97.5% CI lower limit, 55.0%] and 63.0% [1-sided 97.5% lower limit, 46.7%], respectively) exceeded the Center for Biologics Evaluation and Research efficacy criteria. Immunogenicity of both vaccines exceeded the Center for Biologics Evaluation and Research licensing criteria. Both vaccines were well tolerated, with similar safety profiles. Most solicited reactions were mild to moderate in severity and transient. No vaccination-related serious adverse events were reported; no withdrawals resulted from vaccine-related adverse events. CONCLUSIONS: Both CCIV and TIV were effective in preventing influenza caused by vaccine-like and by all circulating influenza virus strains, were well tolerated, and had good safety profiles. Both vaccines can be considered for annual influenza vaccination campaigns. CLINICAL TRIALS REGISTRATION: NCT00630331.

Safety and immunogenicity of an investigational maternal trivalent group B streptococcus vaccine in pregnant women and their infants: Results from a randomized placebo-controlled phase II trial.

BACKGROUND: This study evaluated the safety and immunogenicity of an investigational trivalent group B streptococcus (GBS) vaccine in US pregnant women, transplacental serotype-specific antibody transfer and persistence in infants, and serotype-specific antibodies in breast milk. METHODS: This randomized, observer-blind, placebo-controlled trial administered one dose of trivalent GBS vaccine (n = 49) or placebo (n = 26) to healthy pregnant 18-40-year-old women at 240/7-346/7 weeks' gestation. Women were enrolled from March 2014 to August 2015. Safety follow-up continued through postpartum day 180. Primary immunogenicity objectives were to evaluate serotype Ia/Ib/III-specific immunoglobulin G (IgG) levels in sera from women on day 1 (pre-vaccination), day 31, delivery and postpartum days 42 and 90, and from infants at birth (cord blood), days 42 and 90. Antibody transfer ratios (cord blood/maternal sera at delivery) and serotype-specific secretory immunoglobulin A (sIgA) and IgG in breast milk after delivery and on postpartum days 42 and 90 were evaluated. The planned sample size was not based on statistical assumptions for this descriptive study. RESULTS: Baseline characteristics were similar between groups. Serious adverse events were reported for 16% of GBS-vaccinated women and 15% of their infants, and 15% of placebo recipients and 12% of their infants; none were fatal or deemed vaccine-related. Serotype-specific IgG geometric mean concentrations (GMCs) were 13-23-fold higher in vaccine vs placebo recipients on day 31 and persisted until postpartum day 90. Median antibody concentrations were substantially higher in women with detectable pre-vaccination antibody concentrations. Antibody transfer ratios in the vaccine group were 0.62-0.82. Infant IgG GMCs and breast milk sIgA GMCs were higher in the vaccine vs the placebo group at all timepoints. CONCLUSIONS: Maternal immunization with the trivalent GBS vaccine in US women had a favorable safety profile, elicited antibodies that were transplacentally transferred and persisted in infants for a minimum of 3 months. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, NCT02046148.

Safety and immunogenicity of fully liquid and lyophilized formulations of an investigational trivalent group B streptococcus vaccine in healthy non-pregnant women: Results from a randomized comparative phase II trial.

BACKGROUND: We evaluated the safety and immunogenicity of liquid and lyophilized formulations of an investigational trivalent group B streptococcus (GBS) vaccine in non-pregnant women and assessed the formulations' equivalence in terms of serotype-specific immune response. METHODS: This phase II, randomized, comparative, observer-blind trial enrolled healthy non-pregnant women 18-40 years of age. Women received a single dose of fully liquid (n = 529) or lyophilized (n = 521) trivalent GBS vaccine on day 1. Safety assessments were performed up to day 181 (study termination). Serotype Ia/Ib/III-specific immunoglobulin G (IgG) antibodies were measured in sera from women on day 1 (pre-vaccination) and day 31. Equivalence between the two formulations was demonstrated if the two-sided 95% confidence interval (CI) for the ratio (liquid/lyophilized) of the geometric mean concentrations (GMCs) on day 31 was contained in a (0.5, 2.0) interval for each serotype. RESULTS: Solicited and unsolicited adverse events were reported at similar rates for both formulations. Serious adverse events were reported for six (1.1%) liquid GBS and nine (1.7%) lyophilized GBS vaccinated women, none of which were considered related to vaccination or fatal. On day 31, serotype-specific IgG concentrations were 8-16-fold higher than on day 1 in both groups. Equivalence of the liquid to the lyophilized formulation 30 days post-vaccination was demonstrated as the 95% CIs of the GMC ratios were within the pre-specified interval for the three serotypes: GMC ratios were 1.02 (95% CI: 0.79, 1.32) for serotype Ia, 0.93 (0.71, 1.21) for serotype Ib and 0.99 (0.76, 1.30) for serotype III. CONCLUSIONS: Both formulations of the investigational trivalent GBS vaccine had favorable safety profiles and induced similar GBS serotype-specific antibody concentrations. This study demonstrated that the fully liquid formulation was equivalent to the lyophilized formulation in healthy non-pregnant women in terms of immunogenicity for all three serotypes. CLINICAL TRIALS REGISTRATION: NCT02270944.

Second five-year follow-up after a booster vaccination against tick-borne encephalitis following different primary vaccination schedules demonstrates at least 10 years antibody persistence.

BACKGROUND: Tick borne encephalitis (TBE) endemic zones are expanding. We previously evaluated long term persistence of antibody 5 years after the first booster immunization following different primary immunization schedules with the polygeline-free inactivated TBE vaccine (TBEvac) in adults and adolescents. Here, we report anti-TBE virus (TBEV) antibody persistence from 6 to 10 years post-booster administration. METHODS: This was a phase IV, open-label, single-center, second extension study (NCT01562444), conducted in Czechia. Healthy adults and adolescents ≥12 years who had received 3 different primary vaccination schedules (rapid, conventional and accelerated conventional) in the parent study and a booster dose before (12-18 months post-primary series completion) or at the beginning (3 years post-primary series completion) of the first extension study were screened and enrolled in this study. Blood samples were collected yearly and anti-TBEV antibody response was evaluated by neutralizing test (NT) antibody assays. Analysis was performed overall and per age strata: 15-49 years, ≥50 years, and ≥60 years. RESULTS: Of 206 screened individuals, 191 completed the study. Overall, 90-100% of participants in the all-screened set and ≥97% in the per-protocol set had the clinically meaningful threshold of protection (NT titers ≥10) across all timepoints, regardless of the primary vaccination schedule. Overall, antibody geometric mean titers (GMTs) varied from 134 to 343 in the all-screened set. Older age groups showed overall lower GMTs, although GMTs remained higher than NT titers ≥10 up to year 10 in all groups. CONCLUSION: This study showed long-term persistence of anti-TBEV NT antibodies for up to 10 years after the first booster dose of TBEvac in all age groups, regardless of the primary vaccination schedule.

MenACWY-CRM conjugate vaccine booster dose given 4-6 years after priming: Results from a phase IIIb, multicenter, open label study in adolescents and adults.

BACKGROUND: Vaccination strategies against bacterial meningitis vary across countries. In the United States, a single dose of quadrivalent meningococcal conjugate vaccine (MenACWY) is recommended at 11-12 years of age, with a booster dose approximately 5 years later. We assessed immune responses to a booster dose of MenACWY-CRM vaccine after priming with MenACWY-CRM or MenACWY-D vaccines in adolescents and adults. METHODS: In this phase IIIb, multicenter, open-label study, healthy 15-55-year-olds, who received MenACWY-CRM (N = 301) or MenACWY-D (N = 300) 4-6 years earlier or were meningococcal vaccine-naïve (N = 100), received one MenACWY-CRM vaccine dose. Immunogenicity was evaluated pre-vaccination, 3 or 5 days post-vaccination (sampling subgroups), and 28 days post-vaccination by serum bactericidal activity assay using human complement (hSBA). After vaccination, participants were monitored for 7 days for reactogenicity, 29 days for unsolicited adverse events (AEs), and 181 days for serious AEs and medically-attended AEs. RESULTS: Sufficiency of the immune response to a MenACWY-CRM booster dose was demonstrated; the lower limit of the 1-sided 97.5% confidence interval for percentages of participants with hSBA seroresponse at 28 days post-vaccination was >75% for each serogroup in those primed with either the MenACWY-CRM or MenACWY-D vaccine. Seroresponse was observed in ≥93.24% of primed participants and ≥35.87% of naïve participants 28 days post-vaccination. At 5 days post-booster, among primed participants, hSBA titers ≥1:8 were achieved in ≥47.14% of participants for MenA and in ≥85.52% of participants for MenC, MenW and MenY, and 3.25- to 8.59-fold increases in hSBA geometric mean titers against each vaccine serogroup were observed. No safety concerns were raised throughout the 6-month follow-up period. CONCLUSIONS: A booster dose of the MenACWY-CRM vaccine induced a robust and rapid anamnestic response in adolescents and adults, irrespectively of either MenACWY-CRM or MenACWY-D vaccine administered 4-6 years earlier, with an acceptable clinical safety profile. ClinicalTrials.gov registration: NCT02986854.

A phase I, randomized, controlled, dose-ranging study of investigational acellular pertussis (aP) and reduced tetanus-diphtheria-acellular pertussis (TdaP) booster vaccines in adults.

Despite high vaccination coverage worldwide, pertussis has re-emerged in many countries. This randomized, controlled, observer-blind phase I study and extension study in Belgium (March 2012-June 2015) assessed safety and immunogenicity of investigational acellular pertussis vaccines containing genetically detoxified pertussis toxin (PT) (NCT01529645; NCT02382913). 420 healthy adults (average age: 26.8 ± 5.5 years, 60% female) were randomized to 1 of 10 vaccine groups: 3 investigational aP vaccines (containing pertussis antigens PT, filamentous hemagglutinin [FHA] and pertactin [PRN] at different dosages), 6 investigational TdaP (additionally containing tetanus toxoid [TT] and diphtheria toxoid [DT]), and 1 TdaP comparator containing chemically inactivated PT. Antibody responses were evaluated on days 1, 8, 30, 180, 365, and approximately 3 years post-booster vaccination. Cell-mediated immune responses and PT neutralization were evaluated in a subset of participants in pre-selected groups. Local and systemic adverse events (AEs), and unsolicited AEs were collected through day 7 and 30, respectively; serious AEs and AEs leading to study withdrawal were collected through day 365 post-vaccination. Antibody responses against pertussis antigens peaked at day 30 post-vaccination and then declined but remained above baseline level at approximately 3 years post-vaccination. Responses to FHA and PRN were correlated to antigen dose. Antibody responses specific to PT, toxin neutralization activity and persistence induced by investigational formulations were similar or significantly higher than the licensed vaccine, despite lower PT doses. Of 15 serious AEs, none were considered vaccination-related; 1 led to study withdrawal (premature labor, day 364; aP4 group). This study confirmed the potential benefits of genetically detoxified PT antigen. All investigational study formulations were well tolerated.

One-year immunogenicity kinetics and safety of a purified chick embryo cell rabies vaccine and an inactivated Vero cell-derived Japanese encephalitis vaccine administered concomitantly according to a new, 1-week, accelerated primary series.

BACKGROUND: Conventional rabies pre-exposure prophylaxis (PrEP) and Japanese encephalitis (JE) primary series vaccination regimens each require up to 4 weeks to complete and, thus, may not be feasible for individuals who need these immunizations on short notice. This Phase 3b, randomized, controlled, observer-blind study evaluated the immunogenicity and safety of concomitant administration of a purified chick embryo cell culture rabies vaccine and an inactivated, adsorbed JE vaccine according to an accelerated (1 week) regimen when compared with the conventional regimens (4 weeks). This report describes the kinetics of immune responses up to 1 year after vaccination. METHODS: A total of 661 healthy adults (18 to ≤65 years) were randomized into the following accelerated or conventional vaccine regimens: Rabies + JE-Conventional, Rabies + JE-Accelerated, Rabies-Conventional and JE-Conventional. Immunogenicity was assessed by virus neutralization tests. Safety and tolerability were also evaluated. RESULTS: Irrespective of rabies vaccination regimen, ≥97% of subjects had adequate levels of rabies virus neutralizing antibody (RVNA) concentrations (≥0.5 IU/ml) up to Day 57, with percentages of subjects with RVNA concentrations ≥0.5 IU/ml at Day 366 ranging between 68% in the Rabies + JE-Accelerated group and 80% of subjects in the Rabies-Conventional group. The Rabies + JE-Accelerated group revealed high JE neutralizing antibody titers at all-time points. At Day 366, the percentage of subjects with antibody titers indicative of seroprotection (PRNT50 titers ≥1:10) remained high across JE vaccine groups (86-94%). CONCLUSIONS: The accelerated PrEP rabies and JE vaccination regimens, once licensed, could represent a valid alternative in the short-term to currently recommended conventional regimens. The concomitant administration of these two vaccines does not compromise immune responses to any of the vaccine antigens particularly when aiming for short-term protection. Further evidence will clarify the need for and timing to administration of rabies vaccine booster doses in subjects primed with an accelerated PrEP regimen. (NCT01662440).

Safety and immunogenicity of an MF59-adjuvanted A/H1N1 pandemic influenza vaccine in children from three to seventeen years of age.

OBJECTIVES: This study was designed to identify the optimal dose of an MF59-adjuvanted, monovalent, A/H1N1 influenza vaccine in healthy paediatric subjects. METHODS: Subjects aged 3-8 years (n=194) and 9-17 years (n=160) were randomized to receive two primary doses of A/H1N1 vaccine containing either 3.75 µg antigen with half a standard dose of MF59 adjuvant, 7.5 µg antigen with a full dose of MF59, or (children 3-8 years only), a non-adjuvanted 15 µg formulation. A booster dose of MF59-adjuvanted seasonal influenza vaccine including homologous A/H1N1 strain was given one year after priming. Immunogenicity was assessed by haemagglutination inhibition (HI) and microneutralization assays. Vaccine safety was assessed throughout the study (up to 18 months). RESULTS: A single priming dose of either MF59-adjuvanted formulation was sufficient to meet the European licensure criteria for pandemic influenza vaccines (HI titres ≥1:40>70%; seroconversion>40%; and GMR>2.5). Two non-adjuvanted vaccine doses were required to meet the same licensure criteria. After first and second doses, percentage of subjects with HI titres ≥1:40 were between 97% and 100% in the adjuvanted vaccine groups compared with 68% and 91% in the non-adjuvanted group, respectively. Postvaccination seroconversion rates ranged from 91% to 98% in adjuvanted groups and were 68% (first dose) and 98% (second dose) in the non-adjuvanted group. HI titres ≥1:330 after primary doses were achieved in 69% to 90% in adjuvanted groups compared with 41% in the non-adjuvanted group. Long-term antibody persistence after priming and a robust antibody response to booster immunization were observed in all vaccination groups. All A/H1N1 vaccine formulations were generally well tolerated. No vaccine-related serious adverse events occurred, and no subjects were withdrawn from the study due to an adverse event. CONCLUSIONS: An MF59-adjuvanted influenza vaccine containing 3.75 µg of A/H1N1 antigen was well tolerated and sufficiently immunogenic to meet all the European licensure criteria after a single dose in healthy children 3-17 years old.

Immunogenicity and safety of cell-derived MF59®-adjuvanted A/H1N1 influenza vaccine for children.

Mass immunization of children has the potential to decrease infection rates and prevent the transmission of influenza. We evaluated the immunogenicity, safety, and tolerability of different formulations of cell-derived MF59-adjuvanted and nonadjuvanted A/H1N1 influenza vaccine in children and adolescents. This was a randomized, single-blind, multicenter study with a total of 666 healthy subjects aged 6 months-17 y in one of 3 vaccination groups, each receiving formulations containing different amounts of influenza A/H1N1 antigen with or without MF59. A booster trivalent seasonal MF59 vaccine was administered one year after primary vaccinations. Antibody titers were assessed by hemagglutination inhibition (HI) and microneutralization assays obtained on days 1, 22, 43, 366, and 387 (3 weeks post booster). Safety was monitored throughout the study. One vaccination with 3.75 µg of A/H1N1 antigen formulated with 50% MF59 (3.75_halfMF59) or 7.5 µg of A/H1N1 antigen formulated with 100% MF59 (7.5_fullMF59) induced an HI titer ≥1:40 in >70% of children in the 1-<3, 3-8, and 9-17 y cohorts; however, 2 vaccinations with nonadjuvanted 15 µg A/H1N1 antigen were needed to achieve this response in the 1-<3 and 3-8 y cohorts. Among children aged 6-11 months, 1 dose of 7.5_fullMF59 resulted in an HI titer ≥1:40 in >70% while 2 doses of 3.75_halfMF59 were required to achieve this result. All vaccines were well tolerated. Our findings support the immunogenicity and safety of the 3.75_halfMF59 (2 doses for children <12 months) and 7.5_fullMF59 vaccine formulations for use in children and adolescents aged 6 months to 17 y The use of the 3.75_halfMF59 could have the benefit of antigen and adjuvant sparing, increasing the available vaccine doses allowing vaccination of more people.

Evaluation of rabies immunogenicity and tolerability following a purified chick embryo cell rabies vaccine administered concomitantly with a Japanese encephalitis vaccine.

BACKGROUND: For individuals traveling at short notice to rabies and Japanese encephalitis (JE) endemic countries, concomitant administration of travel vaccines within a short period is often required. METHODS: The aim of this study was to determine whether an accelerated (one-week: Days 1-8) pre-exposure rabies (Rabipur(®), Novartis Vaccines) vaccination regimen administered concomitantly with a Japanese encephalitis (JE) vaccination (Ixiaro(®), Valneva) regimen, is non-inferior to the standard (four-week: Days 1, 8, 29) rabies regimen administered alone or concomitantly with the JE vaccine. Healthy adults (18 to ≤ 65 years) were randomized into Rabies + JE-Standard, Rabies + JE-Accelerated, Rabies-Standard and JE-Standard groups. Relative immunogenicity for rabies in each regimen was assessed using the rapid fluorescent focus inhibition test. Safety was evaluated up to and including Day 57. RESULTS: Non-inferior immunogenicity for rabies was established between the Rabies + JE-Accelerated group compared to both the Rabies-Standard and Rabies + JE-Standard groups; as well as between the Rabies + JE-Standard regimen and the Rabies-Standard regimen. By Day 57, adequate neutralizing levels were achieved by 97-100% of subjects across all groups. Adverse events (AEs) were comparable for all groups. CONCLUSIONS: An accelerated pre-exposure rabies and JE vaccination regimen is non-inferior to the standard four-week rabies regimen and may thus provide a more convenient regimen for individuals traveling to endemic countries at short notice. NCT01662440.

Meningitis C vaccine (North American vaccine).

North American Vaccine Inc (NAVI) has launched a conjugate polysaccharide vaccinefor the prevention of meningitis caused by group C meningococcal bacteria [433475]. The vaccine is based upon conjugate technology, incorporating the serogroup C polysaccharide (CPS) of all three major serogroups. Antibody-dependent, complement-mediated activity was demonstrated in mice and non-human primates, with no detectable adverse effects [277193]. Approval was filed for in the UK in January 2000 [353305]. In July 2000, Baxter received approval for NeisVac-C in the UK, and by September 2000 the vaccine was expected to be incorporated into the NHS's immunization campaign against meningitis C [381225]. NeisVac-C will initially appear labeled from NAVI; Baxter completed its acquisition of NAVI in June 2000 [375389]. Baxter estimates the worldwide global market for the vaccine at US $600 million per year [376204].

Long-term solutions for the problem of vaccine shortages.

During the past few years, vaccine shortage has been a serious problem affecting both developed and developing countries. The explanation is linked to the poor economic value associated with vaccines. Although every year the routine use of vaccines saves millions of lives, the economic value associated with them is negligible, especially if compared with the pharmaceutical market. This situation disincentives private investment, which prefers to focus on more profitable business. To overcome these problems, it is essential to recognise that the intangible value of vaccination (the value of being alive and healthy) represents the real value provided by vaccines. If the intangible value were to be included in the vaccine price, vaccines would become as attractive as other pharmaceuticals. While waiting for a long-term sustainable solution, public-private partnerships represent a way to increase vaccine value awareness and to decrease the risk for vaccine manufacturers. This article will provide examples of how public-private partnerships both in developed and developing countries have been established to handle specific problems concerning vaccination.

A dose-ranging study of MF59(®)-adjuvanted and non-adjuvanted A/H1N1 pandemic influenza vaccine in young to middle-aged and older adult populations to assess safety, immunogenicity, and antibody persistence one year after vaccination.

BACKGROUND: During development of an A/H1N1 pandemic influenza vaccine, this study was performed to identify the antigen and adjuvant content which would provide optimal antibody response and persistence in adults and the elderly. Dose-sparing strategies, such as inclusion of adjuvants, are critical in ensuring the widest possible population coverage in the event of an influenza pandemic, despite a limited global capacity for vaccine manufacture. METHODS: Healthy subjects aged 18-64 years (n = 1240) and ≥65 years (n = 1352) were vaccinated with 1 of 8 investigational vaccine formulations varying in antigen quantity (3.75 µg to 30 µg of hemagglutinin) and MF59(®) adjuvant (none, half dose, or full dose). All subjects received 2 vaccine doses administered 3 weeks apart. Antibody response was assessed by hemagglutination inhibition assay 1 and 3 weeks after administration of first and second doses. Antibody persistence was assessed after 6 and 12 mo. Vaccine safety was monitored over 12 mo. RESULTS: All 8 investigational A/H1N1 vaccine formulations were well tolerated, and rapidly induced high antibody titers which met all of the Center for Biologics Evaluation and Research (CBER) and Committee for Medicinal Products for Human Use (CHMP) licensure criteria 3 weeks after one dose. The highest antibody titers were observed in participants vaccinated with higher quantities of antigen and adjuvant. CONCLUSION: A single vaccine dose containing 3.75 µg of A/California/7/2009 (H1N1) antigen with MF59 adjuvant was identified as optimal for young to middle-aged (18-64 years) and older (≥65 years) adult populations.

Immunogenicity and tolerability of an MF59-adjuvanted, egg-derived, A/H1N1 pandemic influenza vaccine in children 6-35 months of age.

BACKGROUND: Vaccines against pandemic A/H1N1 influenza should provide protective immunity in children, because they are at greater risk of disease than adults. This study was conducted to identify the optimal dose of an MF59®-adjuvanted, egg-derived, A/H1N1 influenza vaccine for young children. METHODS: Children 6-11 months (N = 144) and 12-35 months (N = 186) of age received vaccine formulations containing either 3.75 µg antigen with half the standard dose of MF59 or 7.5 µg antigen with a standard dose of MF59, or a nonadjuvanted formulation containing 15 µg antigen (children 12-35 months only). Participants were given 2 primary vaccine doses 3 weeks apart, followed by 1 booster dose of MF59-adjuvanted seasonal influenza vaccine 1 year later. Immunogenicity was assessed by hemagglutination inhibition and microneutralization assays. RESULTS: All vaccine formulations were highly immunogenic and met all 3 European licensure criteria after 2 doses. MF59-adjuvanted vaccines met all licensure criteria after 1 dose in both age cohorts, while nonadjuvanted vaccine did not meet all criteria after 1 dose in children 12-35 months. A single booster dose was highly immunogenic, and stable antibody persistence was observed in response to all vaccines. All vaccines were well tolerated. CONCLUSIONS: In this study, a single dose of 3.75 µg antigen with half the standard dose of MF59 was shown to be optimal, providing adequate levels of immediate and long-term antibodies in pediatric subjects 6-35 months of age. These data demonstrated that MF59 adjuvant allowed for reduced antigen content and promoted significant long-term antibody persistence in children, with a satisfactory safety profile.

mTOR inhibition improves immune function in the elderly.

Inhibition of the mammalian target of rapamycin (mTOR) pathway extends life span in all species studied to date, and in mice delays the onset of age-related diseases and comorbidities. However, it is unknown if mTOR inhibition affects aging or its consequences in humans. To begin to assess the effects of mTOR inhibition on human aging-related conditions, we evaluated whether the mTOR inhibitor RAD001 ameliorated immunosenescence (the decline in immune function during aging) in elderly volunteers, as assessed by their response to influenza vaccination. RAD001 enhanced the response to the influenza vaccine by about 20% at doses that were relatively well tolerated. RAD001 also reduced the percentage of CD4 and CD8 T lymphocytes expressing the programmed death-1 (PD-1) receptor, which inhibits T cell signaling and is more highly expressed with age. These results raise the possibility that mTOR inhibition may have beneficial effects on immunosenescence in the elderly.