Quadrivalent Influenza Vaccine Prevents Illness and Reduces Healthcare Utilization Across Diverse Geographic Regions During Five Influenza Seasons: A Randomized Clinical Trial.

BACKGROUND: We evaluated an inactivated quadrivalent influenza vaccine (IIV4) in children 6-35 months of age in a phase III, observer-blind trial. METHODS: The aim of this analysis was to estimate vaccine efficacy (VE) in preventing laboratory-confirmed influenza in each of 5 independent seasonal cohorts (2011-2014), as well as vaccine impact on healthcare utilization in 3 study regions (Europe/Mediterranean, Asia-Pacific and Central America). Healthy children were randomized 1:1 to IIV4 or control vaccines. VE was estimated against influenza confirmed by reverse transcription polymerase chain reaction on nasal swabs. Cultured isolates were characterized as antigenically matched/mismatched to vaccine strains. RESULTS: The total vaccinated cohort included 12,018 children (N = 1777, 2526, 1564, 1501 and 4650 in cohorts 1-5, respectively). For reverse transcription polymerase chain reaction confirmed influenza of any severity (all strains combined), VE in cohorts 1-5 was 57.8%, 52.9%, 73.4%, 30.3% and 41.4%, respectively, with the lower limit of the 95% confidence interval >0 for all estimates. The proportion of vaccine match for all strains combined in each cohort was 0.9%, 79.3%, 72.5%, 24.1% and 28.6%, respectively. Antibiotic use associated with influenza illness was reduced with IIV4 by 71% in Europe, 36% in Asia Pacific and 59% in Central America. CONCLUSIONS: IIV4 prevented influenza in children 6-35 months of age in each of 5 separate influenza seasons in diverse geographical regions. A possible interaction between VE, degree of vaccine match and socioeconomic status was observed. The IIV4 attenuated the severity of breakthrough influenza illness and reduced healthcare utilization, particularly antibiotic use.

Meeting report: Convening on the influenza human viral challenge model for universal influenza vaccines, Part 1: Value; challenge virus selection; regulatory, industry and ethical considerations; increasing standardization, access and capacity.

In response to global interest in the development of a universal influenza vaccine, the Bill & Melinda Gates Foundation, PATH, and the Global Funders Consortium for Universal Influenza Vaccine Development convened a meeting of experts (London, UK, May 2018) to assess the role of a standardized controlled human influenza virus infection model (CHIVIM) towards the development of novel influenza vaccine candidates. This report (in two parts) summarizes those discussions and offers consensus recommendations. This article (Part 1) covers challenge virus selection, regulatory and ethical considerations, and issues concerning standardization, access, and capacity. Part 2 covers specific methodologic considerations. Current methods for influenza vaccine development and licensure require large costly field trials. The CHIVIM requires fewer subjects and the controlled setting allows for better understanding of influenza transmission and host immunogenicity. The CHIVIM can be used to identify immune predictors of disease for at-risk populations and to measure efficacy of potential vaccines for further development. Limitations to the CHIVIM include lack of standardization, limited access to challenge viruses and assays, lack of consensus regarding role of the CHIVIM in vaccine development pathway, and concerns regarding risk to study participants and community. To address these issues, the panel of experts recommended that WHO and other key stakeholders provide guidance on standardization, challenge virus selection, and risk management. A common repository of well-characterized challenge viruses, harmonized protocols, and standardized assays should be made available to researchers. A network of research institutions performing CHIVIM trials should be created, and more study sites are needed to increase capacity. Experts agreed that a research network of institutions working with a standardized CHIVIM could contribute important data to support more rapid development and licensure of novel vaccines capable of providing long-lasting protection against seasonal and pandemic influenza strains.

Convening on the influenza human viral challenge model for universal influenza vaccines, Part 2: Methodologic considerations.

In response to global interest in the development of a universal influenza vaccine, the Bill & Melinda Gates Foundation, PATH, and the Global Funders Consortium for Universal Influenza Vaccine Development convened a meeting of experts (London, UK, May 2018) to assess the role of a standardized controlled human influenza virus infection model (CHIVIM) towards the development of novel influenza vaccine candidates. This report (in two parts) summarizes those discussions and offers consensus recommendations. Part 1 covers challenge virus selection, regulatory and ethical considerations, and issues concerning standardization, access, and capacity. This article (Part 2) summarizes the discussion and recommendations concerning CHIVIM methods. The panelists identified an overall need for increased standardization of CHIVIM trials, in order to produce comparable results that can support universal vaccine licensure. Areas of discussion included study participant selection and screening, route of exposure and dose, devices for administering challenge, rescue therapy, protection of participants and institutions, clinical outcome measures, and other considerations. The panelists agreed upon specific recommendations to improve the standardization and usefulness of the model for vaccine development. Experts agreed that a research network of institutions working with a standardized CHIVIM could contribute important data to support more rapid development and licensure of novel vaccines capable of providing long-lasting protection against seasonal and pandemic influenza strains.

Clinical Presentation of Influenza in Children 6 to 35 Months of Age: Findings From a Randomized Clinical Trial of Inactivated Quadrivalent Influenza Vaccine.

BACKGROUND: In an exploratory analysis of an inactivated quadrivalent influenza vaccine (IIV4) trial in children 6-35 months without risk factors for influenza, we evaluated clinical presentation of influenza illness and vaccine impact on health outcomes. METHODS: This phase III trial was conducted in 13 geographically diverse countries across 5 influenza seasons (2011-2014). Children were randomized 1:1 to IIV4 or control. Active surveillance was performed for influenza-like episodes (ILE); influenza was confirmed by reverse transcription polymerase chain reaction (RT-PCR). The total vaccinated cohort was evaluated (N = 12,018). RESULTS: 5702 children experienced ≥1 ILE; 356 (IIV4 group) and 693 (control group) children had RT-PCR-confirmed influenza. Prevalence of ILE was similar in RT-PCR-positive and RT-PCR-negative cases regardless of vaccination. Breakthrough influenza illness was attenuated in children vaccinated with IIV4; moderate-to-severe illness was 41% less likely to be reported in the IIV4 group than the control group [crude odds ratio: 0.59 (95% confidence intervals: 0.44-0.77)]. Furthermore, fever >39°C was 46% less frequent following vaccination with IIV4 than with control [crude odds ratio: 0.54 (95% confidence intervals: 0.39-0.75)] in children with breakthrough illness. Health outcome analysis showed that, each year, IIV4 would prevent 54 influenza cases per 1000 children and 19 children would need to be vaccinated to prevent 1 new influenza case. CONCLUSIONS: In addition to preventing influenza in 50% of participants, IIV4 attenuated illness severity and disease burden in children who had a breakthrough influenza episode despite vaccination.

Anamnestic Immune Response and Safety of an Inactivated Quadrivalent Influenza Vaccine in Primed Versus Vaccine-Naïve Children.

BACKGROUND: It has not yet been demonstrated whether 2 doses of inactivated quadrivalent influenza vaccine (IIV4) prime a booster response in infants. We evaluated the anamnestic immune response to an IIV4 in children 17-48 months of age. METHODS: Children were randomized to 2 doses of IIV4 or control in the primary phase III study (NCT01439360). One year later, in an open-label revaccination extension study (NCT01702454), a subset of children who received IIV4 in the primary study (primed group) received 1 IIV4 dose and children who received control in the primary study (unprimed) received 2 IIV4 doses 28 days apart. The primary objective was to evaluate hemagglutination inhibition (HI) antibody titers 7 days after first IIV4 vaccination in the per-protocol cohort (N = 224 primed; N = 209 unprimed). Neutralizing and antineuraminidase antibodies were also measured. Safety was analyzed in the total vaccinated cohort (N = 241 primed; N = 229 unprimed). RESULTS: An anamnestic response was observed in primed children relative to unprimed controls, measured by age-adjusted geometric mean HI titer ratios against strains homologous (A/H1N1: 9.0; B/Victoria: 3.9) and heterologous (A/H3N2: 2.7; B/Yamagata: 6.7) to those in the primary vaccination series. The anamnestic response in primed children included increases in neutralizing antibodies (mean geometric increase: 5.0-10.6) and antineuraminidase antibodies (4.9-8.8). No serious adverse events related to vaccination were reported. CONCLUSIONS: In this study, 2-dose priming with IIV4 induced immune memory that was recalled with 1-dose IIV4 the following year to boost HI, antineuraminidase and neutralizing antibodies, even though the IIV4 strain composition partially changed.

Prevention of vaccine-matched and mismatched influenza in children aged 6-35 months: a multinational randomised trial across five influenza seasons.

BACKGROUND: Despite the importance of vaccinating children younger than 5 years, few studies evaluating vaccine prevention of influenza have been reported in this age group. We evaluated efficacy of an inactivated quadrivalent influenza vaccine (IIV4) in children aged 6-35 months. METHODS: In this phase 3, observer-blinded, multinational trial, healthy children from 13 countries in Europe, Central America, and Asia were recruited in five independent cohorts, each in a different influenza season. Participants were randomly assigned (1:1) to either IIV4 (15 µg haemagglutinin antigen per strain per 0·5 mL dose; a single dose on day 0 for vaccine-primed children, and two doses, on days 0 and 28, for vaccine-unprimed children) or to one or two doses of a non-influenza control vaccine. Primary endpoints were moderate-to-severe influenza or all influenza (irrespective of disease severity) confirmed by RT-PCR on nasal swabs. Cultured isolates were further characterised as antigenically matched or mismatched to vaccine strains. Efficacy was assessed in the per-protocol cohort and total vaccinated cohort (time-to-event analysis), and safety was assessed in the total vaccinated cohort. FINDINGS: Between Oct 1, 2011, and Dec 31, 2014, 12 018 children were recruited into the total vaccinated cohort (6006 children in the IIV4 group and 6012 children in the control group). 356 (6%) children in the IIV4 group and 693 (12%) children in the control group had at least one case of RT-PCR-confirmed influenza. Of these 1049 influenza strains, 138 (13%) were A/H1N1, 529 (50%) were A/H3N2, 69 (7%) were B/Victoria, and 316 (30%) were B/Yamagata. Overall, 539 (64%) of 848 antigenically characterised isolates were vaccine-mismatched (16 [15%] of 105 for A/H1N1; 368 [97%] of 378 for A/H3N2; 54 [86%] of 63 for B/Victoria; 101 [33%] of 302 for B/Yamagata). Vaccine efficacy was 63% (97·5% CI 52-72) against moderate-to-severe influenza and 50% (42-57) against all influenza in the per-protocol cohort, and 64% (53-73) against moderate-to-severe influenza and 50% (42-57) against all influenza in the total vaccinated cohort. There were no clinically meaningful safety differences between IIV4 and control. INTERPRETATION: IIV4 prevented influenza A and B in children aged 6-35 months despite high levels of vaccine mismatch. Vaccine efficacy was highest against moderate-to-severe disease, which is the most clinically important endpoint associated with greatest burden. FUNDING: GlaxoSmithKline Biologicals SA.

Assessment of an optimized manufacturing process for inactivated quadrivalent influenza vaccine: a phase III, randomized, double-blind, safety and immunogenicity study in children and adults.

BACKGROUND: GSK has modified the licensed monovalent bulk manufacturing process for its split-virion inactivated quadrivalent influenza vaccine (IIV4) to harmonize the process among different strains, resulting in an increased number of finished vaccine doses, while compensating for the change from inactivated trivalent influenza vaccine (IIV3) to IIV4. To confirm the manufacturing changes do not alter the profile of the vaccine, a clinical trial was conducted to compare IIV4 made by the currently licensed process with a vaccine made by the new (investigational) process (IIV4-I). The main objectives were to compare the reactogenicity and safety of IIV4-I versus IIV4 in all age groups, and to demonstrate the non-inferiority of the hemagglutination-inhibition (HI) antibody responses based on the geometric mean titer ratio of IIV4-I versus IIV4 in children. METHODS: The Phase III, randomized, double-blind, multinational study included three cohorts: adults (18-49 years; N = 120), children (3-17 years; N = 821), and infants (6-35 months; N = 940). Eligible subjects in each cohort were randomized 1:1 to receive IIV4-I or IIV4. Both vaccines contained 15 µg of hemagglutinin antigen for each of the four seasonal virus strains. Adults and vaccine-primed children received one dose of vaccine, and vaccine-unprimed children received two doses of vaccine 28 days apart. All children aged ≥9 years were considered to be vaccine-primed and received one dose of vaccine. RESULTS: The primary immunogenicity objective of the study was met in demonstrating immunogenic non-inferiority of IIV4-I versus IIV4 in children. The IIV4-I was immunogenic against all four vaccine strains in each age cohort. The reactogenicity and safety profile of IIV4-I was similar to IIV4 in each age cohort, and there was no increase in the relative risk of fever (≥38 °C) with IIV4-I versus IIV4 within the 7-day post-vaccination period in infants (1.06; 95% Confidence Interval: 0.75, 1.50; p = 0.786). CONCLUSIONS: The study demonstrated that in adults, children, and infants, the IIV4-I made using an investigational manufacturing process was immunogenic with a reactogenicity and safety profile that was similar to licensed IIV4. These results support that the investigational process used to manufacture IIV4-I is suitable to replace the current licensed process. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02207413 ; trial registration date: August 4, 2014.

Immunogenicity and safety of an inactivated quadrivalent influenza vaccine co-administered with a 23-valent pneumococcal polysaccharide vaccine versus separate administration, in adults ≥50years of age: Results from a phase III, randomized, non-inferiority trial.

INTRODUCTION: We compared co-administration versus separate administration of an inactivated quadrivalent influenza vaccine (IIV4) with a 23-valent pneumococcal polysaccharide vaccine (PPV23) in adults at high risk of complications of influenza and pneumococcal infection. METHODS: This phase III, placebo-controlled, observer-blind trial (NCT02218697) was conducted in France and Belgium during the 2014-2015 influenza season. Adults≥50years of age meeting their country's vaccination recommendations were randomized 1:1 to co-administration or separate administration. Immunogenicity was assessed by hemagglutination inhibition (HI) titers for IIV4 and 22F-inhibition ELISA for PPV23. Co-primary objectives were to demonstrate non-inferiority of co-administration versus separate administration in terms of geometric mean titer (GMT) ratio for each influenza strain in the IIV4 and geometric mean concentration (GMC) ratio for six pneumococcal serotypes (1, 3, 4, 7F, 14, 19A) in the PPV23 in the per-protocol cohort (N=334). RESULTS: The study met its co-primary objectives, with the upper limit of the 95% confidence interval of the GMT and GMC ratios (separate administration over co-administration) being ≤2.0 for all four antigens of the IIV4 and the six pre-selected serotypes of the PPV23, respectively. Immunogenicity of the IIV4 and PPV23 was similar regardless of administration schedule. In a post hoc analysis pooling participants ≥60years of age from the co-administration and separate administration groups, IIV4 immunogenicity was similar in higher risk adults with comorbidities (diabetes; respiratory, heart, kidney, liver, or neurological diseases; morbid obesity) versus those without. Both vaccines had an acceptable safety and reactogenicity profile; pain was the most common symptom, occurring more often with co-administration than separate administration. CONCLUSION: The IIV4 and PPV23 can be co-administered without reducing antibody responses reflecting protection against influenza or pneumococcal disease. Co-administration of PPV23 at the annual influenza vaccination visit may improve uptake. Comorbidities had no impact on IIV4 immunogenicity, supporting its value in older adults with chronic medical conditions. Clinical Trial Registry Number: NCT02218697.

Immunogenicity and safety of Southern Hemisphere inactivated quadrivalent influenza vaccine: a Phase III, open-label study of adults in Brazil

Abstract The World Health Organization influenza forecast now includes an influenza B strain from each of the influenza B lineages (B/Yamagata and B/Victoria) for inclusion in seasonal influenza vaccines. Traditional trivalent influenza vaccines include an influenza B strain from one lineage, but because two influenza B lineages frequently co-circulate, the effectiveness of trivalent vaccines may be reduced in seasons of influenza B vaccine-mismatch. Thus, quadrivalent vaccines may potentially reduce the burden of influenza compared with trivalent vaccines.In this Phase III, open-label study, we assessed the immunogenicity and safety of Southern Hemisphere inactivated quadrivalent influenza vaccine (Fluarix™ Tetra) in Brazilian adults (NCT02369341). The primary objective was to assess hemagglutination-inhibition antibody responses against each vaccine strain 21 days after vaccination in adults (aged ≥18–60 years) and older adults (aged >60 years). Solicited adverse events for four days post-vaccination, and unsolicited adverse events and serious adverse events for 21 days post-vaccination were also assessed.A total of 63 adults and 57 older adults received one dose of inactivated quadrivalent influenza vaccine at the beginning of the 2015 Southern Hemisphere influenza season. After vaccination, in adults and older adults, the hemagglutination-inhibition titers fulfilled the European licensure criteria for immunogenicity. In adults, the seroprotection rates with HI titer ≥1:40 were 100% (A/H1N1), 98.4% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria); in older adults were 94.7% (A/H1N1), 96.5% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria). Pain was the most common solicited local adverse events in adults (27/62) and in older adults (13/57), and the most common solicited general adverse events in adults was myalgia (9/62), and in older adults were myalgia and arthralgia (both 2/57). Unsolicited adverse events were reported by 11/63 adults and 10/57 older adults.The study showed that inactivated quadrivalent influenza vaccine was immunogenic and well-tolerated in Brazilian adults and older adults.

Time to Change Dosing of Inactivated Quadrivalent Influenza Vaccine in Young Children: Evidence From a Phase III, Randomized, Controlled Trial.

BACKGROUND.: Children under 3 years of age may benefit from a double-dose of inactivated quadrivalent influenza vaccine (IIV4) instead of the standard-dose. METHODS.: We compared the only United States-licensed standard-dose IIV4 (0.25 mL, 7.5 µg hemagglutinin per influenza strain) versus double-dose IIV4 manufactured by a different process (0.5 mL, 15 µg per strain) in a phase III, randomized, observer-blind trial in children 6-35 months of age (NCT02242643). The primary objective was to demonstrate immunogenic noninferiority of the double-dose for all vaccine strains 28 days after last vaccination. Immunogenic superiority of the double-dose was evaluated post hoc. Immunogenicity was assessed in the per-protocol cohort (N = 2041), and safety was assessed in the intent-to-treat cohort (N = 2424). RESULTS.: Immunogenic noninferiority of double-dose versus standard-dose IIV4 was demonstrated in terms of geometric mean titer (GMT) ratio and seroconversion rate difference. Superior immunogenicity against both vaccine B strains was observed with double-dose IIV4 in children 6-17 months of age (GMT ratio = 1.89, 95% confidence interval [CI] = 1.64-2.17, B/Yamagata; GMT ratio = 2.13, 95% CI = 1.82-2.50, B/Victoria) and in unprimed children of any age (GMT ratio = 1.85, 95% CI = 1.59-2.13, B/Yamagata; GMT ratio = 2.04, 95% CI = 1.79-2.33, B/Victoria). Safety and reactogenicity, including fever, were similar despite the higher antigen content and volume of the double-dose IIV4. There were no attributable serious adverse events. CONCLUSIONS.: Double-dose IIV4 may improve protection against influenza B in some young children and simplifies annual influenza vaccination by allowing the same vaccine dose to be used for all eligible children and adults.

Immunogenicity and safety of Southern Hemisphere inactivated quadrivalent influenza vaccine: a Phase III, open-label study of adults in Brazil.

The World Health Organization influenza forecast now includes an influenza B strain from each of the influenza B lineages (B/Yamagata and B/Victoria) for inclusion in seasonal influenza vaccines. Traditional trivalent influenza vaccines include an influenza B strain from one lineage, but because two influenza B lineages frequently co-circulate, the effectiveness of trivalent vaccines may be reduced in seasons of influenza B vaccine-mismatch. Thus, quadrivalent vaccines may potentially reduce the burden of influenza compared with trivalent vaccines. In this Phase III, open-label study, we assessed the immunogenicity and safety of Southern Hemisphere inactivated quadrivalent influenza vaccine (Fluarix™ Tetra) in Brazilian adults (NCT02369341). The primary objective was to assess hemagglutination-inhibition antibody responses against each vaccine strain 21 days after vaccination in adults (aged ≥18-60 years) and older adults (aged >60 years). Solicited adverse events for four days post-vaccination, and unsolicited adverse events and serious adverse events for 21 days post-vaccination were also assessed. A total of 63 adults and 57 older adults received one dose of inactivated quadrivalent influenza vaccine at the beginning of the 2015 Southern Hemisphere influenza season. After vaccination, in adults and older adults, the hemagglutination-inhibition titers fulfilled the European licensure criteria for immunogenicity. In adults, the seroprotection rates with HI titer ≥1:40 were 100% (A/H1N1), 98.4% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria); in older adults were 94.7% (A/H1N1), 96.5% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria). Pain was the most common solicited local adverse events in adults (27/62) and in older adults (13/57), and the most common solicited general adverse events in adults was myalgia (9/62), and in older adults were myalgia and arthralgia (both 2/57). Unsolicited adverse events were reported by 11/63 adults and 10/57 older adults. The study showed that inactivated quadrivalent influenza vaccine was immunogenic and well-tolerated in Brazilian adults and older adults.

Evidence update: GlaxoSmithKline's inactivated quadrivalent influenza vaccines.

Inactivated trivalent influenza vaccines (IIV3s) are designed to protect against illness caused by two influenza A virus subtypes and one influenza B virus lineage. They may provide inadequate protection due to the co-circulation of viruses from two antigenically distinct influenza B lineages. Incorporating strains from both B lineages as in inactivated quadrivalent influenza vaccines (IIV4s) reduces this risk. We summarize the evidence supporting two IIV4s manufactured by GSK Vaccines. Compared to IIV3s, these two IIV4s demonstrated noninferior immunogenicity against the shared influenza strains and superior immunogenicity for the strain of the additional B lineage, particularly in subjects who were seronegative for that B strain. One IIV4's efficacy in children aged 3-8 years was 55.4% against influenza of any severity and 73.1% against moderate-to-severe influenza. Both IIV4s were well-tolerated with a similar safety profile to IIV3s. These IIV4s are more likely than IIV3s to protect against the added influenza B strain.

Immunogenicity and Safety of an Inactivated Quadrivalent Influenza Vaccine in US Children 6-35 Months of Age During 2013-2014: Results From A Phase II Randomized Trial.

BACKGROUND: Viruses from 2 influenza B lineages co-circulate, leading to suboptimal protection with trivalent influenza vaccines (TIV). Quadrivalent influenza vaccines (QIV) containing both lineages offer broader protection. METHODS: We compared inactivated seasonal QIV versus TIV (15 and 7.5 µg hemagglutinin [HA] for each influenza strain, respectively) in a phase II randomized (1 : 1), observer-blind trial in US children 6-35 months of age (identifier NCT01974895). The primary objective was to evaluate immune responses induced by QIV for the 4 vaccine strains 28 days after completion of vaccination. A secondary objective was to demonstrate superiority of QIV versus TIV for the B/Victoria strain contained in QIV but not TIV. Immunogenicity was evaluated in the per-protocol cohort (N = 280), and safety was evaluated in the intent-to-treat cohort (N = 314). RESULTS: Seroconversion rates (SCRs) for QIV were 80.4% (95% confidence interval [CI], 73.0%-86.6%), 72.0% (95% CI, 63.9%-79.2%), 86.0% (95% CI, 79.2%-91.2%), and 66.4% (95% CI, 58.1%-74.1%) for A/H1N1, A/H3N2, B/Yamagata, and B/Victoria, respectively. Quadrivalent influenza vaccines demonstrated immunogenic superiority over TIV for B/Victoria with a geometric mean titer ratio of 4.73 (95% CI, 3.73%-5.99%) and SCR difference of 54.02% (95% CI, 43.88%-62.87%). Safety was similar between the vaccine groups despite the QIV's higher antigen content. No serious adverse events were reported related to vaccination. CONCLUSIONS: Quadrivalent influenza vaccine (15 µg HA/strain) was immunogenic with an acceptable safety profile. The next phase of its development in children 6-35 months of age is a phase III trial in countries where it is not yet licensed. In countries where it is already licensed, a switch from TIV to QIV would provide broader protection in this vulnerable group.

Immunogenicity and Reactogenicity of an Inactivated Quadrivalent Influenza Vaccine Administered Intramuscularly to Children 6 to 35 Months of Age in 2012-2013: A Randomized, Double-Blind, Controlled, Multicenter, Multicountry, Clinical Trial.

BACKGROUND: Influenza attack rates are high in 6- to 35-month-old children; vaccines containing both lineages of influenza B (Yamagata and Victoria), in addition to the H3N2 and H1N1 antigens, may improve protection rates. METHODS: In a randomized double-blind controlled trial, the immunogenicity and reactogenicity of an inactivated quadrivalent influenza vaccine (QIV) and a trivalent control vaccine (TIV) were assessed. RESULTS: Six hundred one children (QIV, n = 299; TIV, n = 302) were enrolled at 8 sites in 3 countries. The primary immunogenicity objective was met: the lower limit (LL) of the 2-sided 95% confidence interval (CI) for the seroconversion rate in QIV recipients ranged from 66.6% to 81.3%, which was ≥40% against all 4 strains. The immunogenic superiority of the additional B/Victoria strain in the QIV compared to that in the TIV was confirmed: the LL of the 2-sided 95% CI of the geometric mean titer ratio (QIV/TIV) (6.28 [95% CI, 5.32-7.41]) was greater than 1.5, and the LL of the 2-sided 95% CI for the difference in the seroconversion rate (QIV - TIV) (64.19% [95% CI, 57.65%-69.95%]) was greater than 10%. Injection-site pain and irritability/fussiness were the most commonly reported solicited injection-site and general adverse events, respectively, from days 0 to 6 and were similar in frequency between the groups. CONCLUSIONS: In children aged 6 to 35 months, a QIV has superior immunogenicity for the added B strain and acceptable immunogenicity for shared strains, with no notable difference in reactogenicity and safety when compared to a TIV.

Immunogenicity and safety of inactivated quadrivalent and trivalent influenza vaccines in children 18-47 months of age.

BACKGROUND: Because inactivated trivalent influenza vaccines (TIVs) contain 1 influenza B strain, whereas 2 lineages may co-circulate, B lineage mismatch is frequent. We assessed an inactivated quadrivalent influenza vaccine (QIV) containing both B lineages versus TIV in young children. METHODS: Children aged 18-47 months who had received 2 doses of TIV in a study during the previous season (primed cohort, n = 192) were randomized 1:1 to receive 1 dose of TIV or QIV, and a further 407 children (unprimed cohort) were randomized 1:1 to receive 2 doses of TIV or QIV 28 days apart. Immunogenicity was assessed by hemagglutination-inhibition (HI) prevaccination and 28 days after each vaccination. Immunogenic non-inferiority QIV versus TIV for shared strains, and superiority against the alternate-lineage B strain were based on HI geometric mean titers (pooled analyses of primed and half of unprimed cohort with Day 56 immunogenicity assessment). Solicited and unsolicited adverse events were assessed during each 7- and 28-day postvaccination period, respectively (NCT00985790). RESULTS: Non-inferiority for shared strains and superiority for the alternate-lineage B strain unique to QIV was demonstrated for QIV versus TIV. QIV was immunogenic against all 4 vaccine strains and 87.0%, 88.6%, 69.8% and 97.9% of children had postvaccination titers of ≥ 1:40 against A/H1N1, A/H3N2, B/Victoria and B/Yamagata, respectively. Reactogenicity and safety of QIV was consistent with TIV. CONCLUSIONS: QIV provided superior immunogenicity for the alternate-lineage B strain compared with TIV without interfering with immune responses to shared strains. Further studies are warranted to assess QIVs in children and to establish the clinical benefits of QIV versus TIV.

A historically-controlled Phase III study in adults to characterize the acceptability of a process change for manufacturing inactivated quadrivalent influenza vaccine.

BACKGROUND: An inactivated quadrivalent influenza vaccine (QIV) was recently licenced in the US as a thimerosal-free formulation presented in a pre-filled syringe. A multidose presentation is preferred in some settings due to reduced acquisition and cold storage costs. We assessed the immunogenicity and safety of a thimerosal-containing QIV formulated using a new manufacturing process for presentation in multidose vials. METHODS: Two Phase III non-randomized studies separately evaluated inactivated trivalent influenza vaccine (TIV; 2010-2011; historical control) and a QIV (2011-2012). The QIV contained the same strains as the TIV plus an additional B strain. Both vaccines contained thimerosal to allow multidose presentation: this preservative was added to the QIV during the final formulation step using a new process, whereas it was added to the TIV early in the manufacturing process using an established method. The TIV study included 50 and 70 subjects aged 18-60 and >60 years, respectively; the QIV study included 56 subjects in each age stratum. Immunogenicity was assessed using hemagglutination-inhibition (HI) assays. Reactogenicity was assessed during the 4-day post-vaccination periods and unsolicited adverse events (AEs) were assessed during the 21-day post-vaccination periods. RESULTS: The TIV and QIV were immunogenic in both age strata. With the QIV and TIV respectively, the seroconversion rates were 48.2-62.7% and 71.4-83.7% for influenza A, and 33.9-62.5% and 67.3-72.9% for influenza B. With the QIV and TIV respectively, the seroprotection rates were 92.9-98.2% and 98.2-100% for influenza A, and 88.6-100% and 95.9-98.6% for influenza B. Pre-vaccination titers were higher in the QIV versus TIV study which confounds a direct comparison and likely explains the lower seroconversion rates observed in the QIV study. There were no safety concerns raised with TIV or QIV. CONCLUSIONS: The thimerosal-containing QIV formulated using a new process was immunogenic, conforming to regulatory acceptance criteria, with a reactogenicity and safety profile in line with the TIV manufactured using a licensed process. These results support acceptability of a manufacturing process change in which the thimerosal preservative is added at the point at which batches are filled into multidose vials. TRIAL REGISTRATION: These trials were registered at ClinicalTrials.gov: NCT01440387; NCT01153685.

Immunogenicity, reactogenicity, and safety of inactivated quadrivalent influenza vaccine candidate versus inactivated trivalent influenza vaccine in healthy adults aged ≥18 years: a phase III, randomized trial.

BACKGROUND: Two influenza B lineages have been co-circulating since the 1980s, and because inactivated trivalent influenza vaccine (TIV) contains only one B strain, it provides little/no protection against the alternate B-lineage. We assessed a candidate inactivated quadrivalent influenza vaccine (QIV) containing both B lineages versus TIV in healthy adults. METHODS: Subjects received one dose of QIV (lot 1, 2, or 3) or one of two TIVs (B strain from Victoria or Yamagata lineage); randomization was 2:2:2:1:1. Hemagglutination-inhibition assays were performed 21-days post-vaccination; superiority of QIV versus TIV for the alternate B-lineage was demonstrated if the 95% confidence interval (CI) lower limit for the GMT ratio was ≥1.5, and non-inferiority against the shared strains was demonstrated if the 95% CI upper limit for the GMT ratio was ≤1.5. Reactogenicity and safety were assessed during the post-vaccination period. NCT01196975. RESULTS: Immunogenicity of QIV lots was consistent, QIV was superior to TIV for the alternate B-lineage strain, and QIV was non-inferior versus TIVs for shared strains (A/H1N1, A/H3N2, B-strain). Reactogenicity and safety profile of the QIV was consistent with seasonal influenza vaccines. CONCLUSION: QIV provided superior immunogenicity for the added B strain without affecting the antibody response to the TIV strains, and without compromising safety.

Vaccine for prevention of mild and moderate-to-severe influenza in children.

BACKGROUND: Commonly used trivalent vaccines contain one influenza B virus lineage and may be ineffective against viruses of the other B lineage. We evaluated the efficacy of a candidate inactivated quadrivalent influenza vaccine (QIV) containing both B lineages. METHODS: In this multinational, phase 3, observer-blinded study, we randomly assigned children 3 to 8 years of age, in a 1:1 ratio, to receive the QIV or a hepatitis A vaccine (control). The primary end point was influenza A or B confirmed by real-time polymerase chain reaction (rt-PCR). Secondary end points were rt-PCR-confirmed, moderate-to-severe influenza and rt-PCR-positive, culture-confirmed influenza. The vaccine efficacy and the effect of vaccination on daily activities and utilization of health care resources were assessed in the total vaccinated cohort (2584 children in each group) and the per-protocol cohort (2379 children in the QIV group and 2398 in the control group). RESULTS: In the total vaccinated cohort, 62 children in the QIV group (2.40%) and 148 in the control group (5.73%) had rt-PCR-confirmed influenza, representing a QIV efficacy of 59.3% (95% confidence interval [CI], 45.2 to 69.7), with efficacy against culture-confirmed influenza of 59.1% (97.5% CI, 41.2 to 71.5). For moderate-to-severe rt-PCR-confirmed influenza, the attack rate was 0.62% (16 cases) in the QIV group and 2.36% (61 cases) in the control group, representing a QIV efficacy of 74.2% (97.5% CI, 51.5 to 86.2). In the per-protocol cohort, the QIV efficacy was 55.4% (95% CI, 39.1 to 67.3), and the efficacy against culture-confirmed influenza 55.9% (97.5% CI, 35.4 to 69.9); the efficacy among children with moderate-to-severe influenza was 73.1% (97.5% CI, 47.1 to 86.3). The QIV was associated with reduced risks of a body temperature above 39°C and lower respiratory tract illness, as compared with the control vaccine, in the per-protocol cohort (relative risk, 0.29 [95% CI, 0.16 to 0.56] and 0.20 [95% CI, 0.04 to 0.92], respectively). The QIV was immunogenic against all four strains. Serious adverse events occurred in 36 children in the QIV group (1.4%) and in 24 children in the control group (0.9%). CONCLUSIONS: The QIV was efficacious in preventing influenza in children. (Funded by GlaxoSmithKline Biologicals; ClinicalTrials.gov number, NCT01218308.).

Immunogenicity and safety of an inactivated quadrivalent influenza vaccine candidate: a phase III randomized controlled trial in children.

BACKGROUND: Mismatch between circulating influenza B viruses (Yamagata and Victoria lineages) and vaccine strains occurs frequently. METHODS: In a randomized controlled trial, immunogenicity and safety of an inactivated quadrivalent influenza vaccine candidate (QIV) versus trivalent inactivated influenza vaccine (TIV)-Victoria(Vic) and TIV-Yamagata(Yam) in children 3-17 years of age was evaluated. In an open-label study arm, QIV only was assessed in children 6-35 months of age. RESULTS: A total of 3094 children (932 QIV, 929 TIV-Vic, 932 TIV-Yam, and 301 QIV only) were vaccinated. QIV was noninferior to the TIVs for shared strains (A/H3N2 and A/H1N1) based on hemagglutination-inhibition (HI) antibodies 28 days after last vaccination, and superior for the unique B strains Victoria and Yamagata (geometric mean titer ratios 2.61, 3.78; seroconversion rate differences 33.96%, 44.63%). Among children in the randomized trial, adverse event rates were similar except for injection site pain (dose 1: 65.4% QIV, 54.6% TIV-Vic, 55.7% TIV-Yam). CONCLUSION: QIV elicited superior HI responses to the added B strains compared to TIV controls, potentially improving its effectiveness against influenza B. HI responses were similar between QIV and TIV controls for the shared strains. QIV had an acceptable safety profile relative to TIVs. CLINICAL TRIALS REGISTRATION: NCT01198756.