Immunogenicity and Safety of AS03-adjuvanted H5N1 Influenza Vaccine in Children 6-35 Months of Age: Results From a Phase 2, Randomized, Observer-blind, Multicenter, Dose-ranging Study.

BACKGROUND: This phase 2 observer-blind, randomized, multicenter, dose-ranging study evaluated immunogenicity and safety of different formulations of an AS03-adjuvanted H5N1 influenza vaccine in children 6-35 months of age. METHODS: One hundred eighty-five children randomized into 5 groups [1.9 µg hemagglutinin (HA)/AS03B, 0.9 µg HA/AS03C, 1.9 µg HA/AS03C, 3.75 µg HA/AS03C or 3.75 µg HA/AS03D] were to receive 2 doses administered 21 days apart (primary vaccination). AS03 was classified by amount of DL-α-tocopherol, with AS03B the highest amount. One year later, all subjects were to receive unadjuvanted 3.75 µg HA as antigen challenge. Immunogenicity was assessed 21 days after primary vaccination (day 42) and 7 days after antigen challenge (day 392). Immunogenicity-fever index, based on hemagglutination inhibition and microneutralization antibody titers at day 42 and fever 7 days after each vaccination, was used to guide the selection of an acceptable formulation. RESULTS: After primary vaccination, formulations elicited strong homologous immune responses with all subjects' hemagglutination inhibition titers ≥1:40 post-vaccination. Immunogenicity-fever index based on hemagglutination inhibition and microneutralization assays showed that 1.9 µg HA/AS03B ranked the highest. Antibody levels persisted >4 times above baseline 12 months after primary vaccination with all formulations (day 385). Antibodies increased >4-fold after antigen challenge (day 392/day 385) with 1.9 µg HA/AS03B, 0.9 µg HA/AS03C and 1.9 µg HA/AS03C formulations. Overall per subject, the incidence of fever ranged from 28.6% (3.75 µg HA/AS03D) to 60.5% (1.9 µg HA/AS03B). CONCLUSIONS: All formulations were highly immunogenic and demonstrated acceptable safety profiles, with the 1.9 µg HA/AS03B providing the most favorable balance of immunogenicity versus reactogenicity for use in children 6-35 months of age.

Immune responses to the adjuvanted recombinant zoster vaccine in immunocompromised adults: a comprehensive overview.

Immunocompromised (IC) persons are at increased risk for herpes zoster (HZ) and its complications, mainly due to impairment of cell-mediated immunity (CMI). The adjuvanted recombinant zoster vaccine (RZV) demonstrated efficacy against HZ in autologous hematopoietic stem cell transplant (auto-HSCT) recipients and hematologic malignancy (HM) patients. We review immune responses to RZV in 5 adult IC populations, 4 of which were receiving multiple, concomitant immunosuppressive medications: auto-HSCT and renal transplant recipients, HM and solid tumor patients, and human immunodeficiency virus-infected adults. Although administered in most cases when immunosuppression was near its maximum, including concomitantly with chemotherapy cycles, RZV induced robust and persistent humoral and, more importantly, CMI responses in all 5 IC populations. Based on the overall clinical data generated in older adults and IC individuals, RZV is expected to provide benefit in a broad adult population at risk for HZ.

Characterization of Bacteria on Aerosols From Dust Events in Dakar, Senegal, West Africa.

We identify bacteria types on collected dust samples in Dakar Senegal, a region that experiences frequent Saharan dust events. We use classical techniques to identify bacteria types from dust samples. Seventy-seven bacteria types are identified from samples collected by spatula and the QuickTake® 30 air sampling pump. The dominant groups in the first batch of 51 bacteria (collected via deposition) are Micrococcus (33.33%), Bacillus (13.73%), Kytococcus (11.76%), Pseudomonas (9.80%), and Burkholderia (7.84%) and dominants in the second batch of 26 bacteria (collected with aerosol sampling vacuum pump): Pseudomonas (38.61%), Burkholderia (26.92%), Micrococcus (11.54%), and Brucella spp (7.69%). These bacteria are found in earlier studies from desert sources and can potentially cause respiratory diseases to exposed populations. Future work will use molecular methods is necessary to search for additional pathogens, including viruses on dust aerosols.

Observed and Modeled Seasonal Air Quality and Respiratory Health in Senegal During 2015 and 2016.

In this work, we use existing particulate matter (PM) data from Dakar, Senegal, satellite aerosol optical depth (AOD) and the Weather Research and Forecasting (WRF) model to evaluate the role of dust transport from the Sahara and PM concentrations and exposure into other administrative districts of Senegal during 2015 and 2016. We also use data from the Ministry of Health to examine spatial and temporal patterns of acute respiratory infections, asthma, bronchitis, and tuberculosis across Senegal with an emphasis on Northern Hemisphere winter December-February, when air quality is poor, and June-August when there is an improvement in air quality. Measurements in Dakar, Senegal, suggest hazardous PM10 concentrations associated with Saharan dust storms but lower PM10 concentrations during the summer. The WRF dust simulations show a similar temporal pattern to the observations in Dakar, Senegal, with notable biases. However, the WRF model suggests that the highest dust concentrations are found across the northern half of Senegal during the winter season where there are no currently PM measurements. Health data during 2015-2016 show the highest prevalence of asthma and bronchitis in Dakar, Senegal, suggesting that other sources of air pollution are important. Acute respiratory infection is prevalent throughout the country with the high prevalence found in rural zones, for children between 12 and 59 months. All measures including real-time monitoring, air quality forecast, and communication should be used to protect the public from potentially hazardous environmental conditions during the winter season.

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.

Evaluation of a primary course of H9N2 vaccine with or without AS03 adjuvant in adults: A phase I/II randomized trial.

BACKGROUND: Avian influenza A H9N2 strains have pandemic potential. METHODS: In this randomized, observer-blind study (ClinicalTrials.gov: NCT01659086), 420 healthy adults, 18-64years of age, received 1 of 10 H9N2 inactivated split-virus vaccination regimens (30 participants per group), or saline placebo (120 participants). H9N2 groups received 2 doses (days 0, 21) of 15µg hemagglutinin (HA) without adjuvant, or 1.9µgHA+AS03A, 1.9µgHA+AS03B, 3.75µgHA+AS03A, or 3.75µgHA+AS03B; followed by the same H9N2 formulation or placebo (day 182). AS03 is an adjuvant system containing α-tocopherol (AS03A: 11.86mg; AS03B: 5.93mg) and squalene in an oil-in-water emulsion. Immunogenicity (hemagglutination inhibition [HI] and microneutralization assays) and safety were assessed up to day 546. RESULTS: All adjuvanted formulations exceeded regulatory immunogenicity criteria at days 21 and 42 (HI assay), with seroprotection and seroconversion rates of ≥94.9% and ≥89.8% at day 21, and 100% and ≥98.1% at day 42. Immunogenicity criteria were also met for unadjuvanted vaccine, with lower geometric mean titers. In groups administered a third vaccine dose (day 182), an anamnestic immune response was elicited with robust increases in HI and microneutralization titers. Injection site pain was reported more frequently with adjuvanted vaccines. No vaccine-related serious adverse events were observed. CONCLUSIONS: All H9N2 vaccine formulations were immunogenic with a clinically acceptable safety profile; adjuvanted formulations were 4-8 times dose-sparing (3.75-1.9vs 15µgHA). TRIAL REGISTRATION: Registered on ClinicalTrials.gov: NCT01659086.

Linkages between observed, modeled Saharan dust loading and meningitis in Senegal during 2012 and 2013.

The Sahara desert transports large quantities of dust over the Sahelian region during the Northern Hemisphere winter and spring seasons (December-April). In episodic events, high dust concentrations are found at the surface, negatively impacting respiratory health. Bacterial meningitis in particular is known to affect populations that live in the Sahelian zones, which is otherwise known as the meningitis belt. During the winter and spring of 2012, suspected meningitis cases (SMCs) were with three times higher than in 2013. We show higher surface particular matter concentrations at Dakar, Senegal and elevated atmospheric dust loading in Senegal for the period of 1 January-31 May during 2012 relative to 2013. We analyze simulated particulate matter over Senegal from the Weather Research and Forecasting (WRF) model during 2012 and 2013. The results show higher simulated dust concentrations during the winter season of 2012 for Senegal. The WRF model correctly captures the large dust events from 1 January-31 March but has shown less skill during April and May for simulated dust concentrations. The results also show that the boundary conditions are the key feature for correctly simulating large dust events and initial conditions are less important.

Assessment of Prime-boost Vaccination Using an AS03B-adjuvanted Influenza A (H5N1) Vaccine: A Randomized Trial in Children of Three to Less Than Eighteen Years of Age.

BACKGROUND: Heterologous prime-boost vaccination is a pandemic response strategy utilizing subtype-matched vaccine at pandemic onset followed by strain-matched vaccine once available. Persistence of immune response and safety of influenza A (H5N1) vaccine adjuvanted with adjuvant system containing α-tocopherol and squalene in an oil-in-water emulsion (AS03B) were evaluated. METHODS: An open phase 3 active-controlled study (www.clinicaltrials.gov NCT01379937) assessed immunogenicity and reactogenicity of a heterologous booster dose of A/turkey/Turkey/1/2005-H5N1-AS03B in children 3 to <18 years of age, given 6 months after 2-dose priming with A/Indonesia/05/2005-H5N1-AS03B (H5N1(2) -H5N1 group) compared with a single dose of A/turkey/Turkey/1/2005-H5N1-AS03B in unprimed subjects (hepatitis A vaccine (HAV)-H5N1 group). Hemagglutinin inhibition responses and microneutralization antibodies were assessed to 6 months after booster vaccination. RESULTS: Hemagglutinin inhibition antibody responses against A/turkey/Turkey/1/2005-H5N1 were superior in the H5N1(2)-H5N1 versus the hepatitis A vaccine-H5N1 group overall and in each age strata (3 to <10 and 10 to <18 years). Anamnestic immune responses were demonstrated against vaccine-homologous/heterologous strains in the H5N1(2)-H5N1 group. Injection site pain and fever increased with consecutive doses for children <6 years (H5N1(2)-H5N1). Immune responses to vaccine-homologous/heterologous strains persisted to 6 months after booster vaccination in the H5N1(2)-H5N1 group. CONCLUSIONS: Heterologous H5N1-AS03B-adjuvanted booster vaccination in children/adolescents was immunogenic for vaccine-homologous and heterologous strains following 2-dose priming, with immune persistence for at least 6 months. Prime-boost strategies using H5N1-AS03 could be effectively employed in this age group.

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

BACKGROUND: AS03-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. METHODS: This Phase IV, randomized, study was conducted to assess the immunogenicity, reactogenicity, and safety of two doses (3.75µg 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). RESULTS: AS03-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. CONCLUSION: The results indicate that AS03-H5N1 vaccine is immunogenic with reactogenicity and safety findings that are consistent with the established profile of AS03-H5N1 vaccine.

Immunogenicity and Safety of an EB66 Cell-Culture-Derived Influenza A/Indonesia/5/2005(H5N1) AS03-Adjuvanted Vaccine: A Phase 1 Randomized Trial.

BACKGROUND: Cell-culture-derived (CC) influenza vaccine production methods could provide benefits over classical embryonated-egg technology, including a higher production capacity and the faster creation of a supply that meets demand. METHODS: A CC-inactivated split-virus influenza A/Indonesia/5/2005(H5N1) vaccine derived from the EB66 cell line (hereafter, "CC-H5N1") was investigated in a phase 1 randomized, blinded study. Healthy adults (n = 521) received 2 vaccine doses (days 0 and 21) of either investigational CC-H5N1 vaccine (1.9 µg or 3.75 µg of hemagglutinin antigen [HA] with the AS03 adjuvant system or 15 µg of plain HA), embryonated-egg-derived vaccines (3.75 µg of HA with AS03 or 15 µg of plain HA), or placebo. Assessment of the adjuvant effect and immunogenicity was performed using Center for Biologics Evaluation and Research acceptability criteria 21 days after dose 2. Safety was assessed until month 12. RESULTS: AS03-adjuvanted CC-H5N1 elicited a homologous hemagglutination inhibition antibody response that satisfied immunogenicity criteria 21 days after dose 2 and persisted at month 12. Adjuvant effect and immune response against a drift-variant strain were demonstrated. No vaccine-related serious adverse events were reported. The immunogenicity and safety of the CC-H5N1 formulation containing 3.75 µg of HA and AS03 appeared to be similar to those for the licensed egg-derived AS03-adjuvanted control vaccine. CONCLUSIONS: The feasibility of the EB66 cell line to produce an immunogenic influenza vaccine with acceptable safety profile was demonstrated. Antigen sparing was achieved through combination with AS03 adjuvant. This CC-H5N1 might contribute to the rapid access of vaccine in the event of an influenza A(H5N1) pandemic. CLINICAL TRIALS REGISTRATION: NCT01236040.

Immunogenicity and safety of AS03A-adjuvanted H5N1 influenza vaccine prepared from bulk antigen after stockpiling for 4 years.

BACKGROUND: Stockpiling vaccine for deployment in the event of an influenza pandemic is an important mitigation strategy. A necessary aspect of stockpiling is to determine the shelf-life of the stored vaccine. METHODS: In this Phase II, open-label study we assessed the immunogenicity and safety of H5N1 A/Indonesia/5/2005 vaccine adjuvanted with AS03A. The AS03A-H5N1 vaccine was prepared from bulk antigen that had been stored for 4 years, and adjuvant that had been stored for 2.5 years. Both the antigen and adjuvant were filled in separate multi-dose vials within 4 months of use, and on the day of vaccination, the contents of antigen and adjuvant vials were mixed. Seventy-eight adults aged 18-64 years were scheduled to receive two doses of hemagglutinin-antigen (3.75µg) given 21 days apart. Antibody responses were assessed by hemagglutination-inhibition (HI) assay according to age (18-30 years, 31-40 years, 41-50 years, and 51-64 years). Reactogenicity was assessed for 7 days after each vaccination, and safety was assessed for 385 days post-vaccination (NCT01416571). RESULTS: The vaccine was immunogenic. Twenty-one days after the second dose of vaccine in the overall population, the HI seroconversion rate and seroprotection rate (SPR; titer ≥1:40) was 96.0% and 98.7%, respectively. At Day 182 after vaccination, the SPR was 76.7% in the overall population. Injection site pain was the most frequent solicited adverse event (91.0%), and no safety concerns were raised. CONCLUSION: The immunogenicity and safety observed with AS03A-H5N1 vaccine formulated with bulk antigen which had been stockpiled before vialing and administration was consistent with that previously observed with newly manufactured AS03A-H5N1 vaccine. This suggests that stockpiling bulk antigen for 4 years does not compromise the immunogenicity or reactogenicity of the vaccine.

Immunogenicity of heterologous H5N1 influenza booster vaccination 6 or 18 months after primary vaccination in adults: a randomized controlled clinical trial.

BACKGROUND: Highly pathogenic avian influenza A/H5N1 viruses continue to circulate in birds and infect humans causing serious illness and death. METHODS: In this randomized, observer-blinded study, adults ≥18 years of age (n=841) received 3.75 or 7.5 µg hemagglutinin antigen (HA) of an AS03-adjuvanted (AS03A or AS03B) A/Indonesia/5/2005 H5N1 (subclade 2.1) vaccine (priming), followed by the same HA dose of AS03-adjuvanted A/turkey/Turkey/1/05 H5N1 (clade 2.2) influenza vaccine as a booster 6 or 18 months after priming; an unprimed group received placebo at Day 0, and 3.75 µg HA of AS03A-adjuvanted booster vaccine at 6 and 18 months. Antibody responses were assessed by hemagglutination-inhibition assay (HI). Microneutralization (MN) antibody and cellular immunoassays were assessed in a subset of participants. RESULTS: Geometric mean titers (GMTs) and seroconversion rates (SCRs) were higher in primed vs. unprimed subjects against the booster strain 10 days following booster vaccination at month 6 and month 18. After the booster at 18 months, the lower limit of the 97.5% confidence interval for the difference in SCR and GMT ratios between primed and unprimed subjects was >15% and >2.0, respectively, fulfilling the primary endpoint criteria for superiority against the booster strain. MN and cellular immune responses corresponded with the immunogenicity seen in HI measures. CONCLUSIONS: Adults primed with a dose-sparing oil-in-water adjuvanted H5N1 subclade vaccine had rapid and durable antibody responses to a heterologous subclade boosting vaccine given 6 or 18 months later.

AS03B-adjuvanted H5N1 influenza vaccine in children 6 months through 17 years of age: a phase 2/3 randomized, placebo-controlled, observer-blinded trial.

BACKGROUND: This phase 2/3, randomized, placebo-controlled, observer-blinded study assessed the immunogenicity, reactogenicity, and safety of an inactivated, split-virion H5N1 influenza vaccine (A/Indonesia/5/2005) in children aged 6 months through 17 years. METHODS: Children received 2 influenza vaccine doses 21 days apart, each containing 1.9 µg of hemagglutinin and AS03B adjuvant (5.93 mg of α-tocopherol). The randomization ratio was 8:3 for vaccine to placebo, with equal allocation between 3 age strata (6-35 months, 3-8 years, and 9-17 years). Immunogenicity against the vaccine strain was assessed 21 days after the first and second vaccine doses for all vaccinees, at day 182 for half, and at day 385 for the remaining half. Reactogenicity after each dose and safety up to 1 year after vaccination were evaluated. RESULTS: Within each age stratum, the lower limit of the 98.3% confidence interval for the day 42 seroprotection rate was ≥70%, thus fulfilling the US and European licensure criteria. The immune responses elicited by vaccine persisted well above baseline levels for 1 year. The vaccine was more reactogenic than placebo, but no major safety concerns were identified. CONCLUSIONS: AS03B-adjuvanted H5N1 influenza vaccine was immunogenic and showed an acceptable safety profile in all age groups studied. Clinical Trials Registration: NCT01310413.

Safety of AS03-adjuvanted inactivated split virion A(H1N1)pdm09 and H5N1 influenza virus vaccines administered to adults: pooled analysis of 28 clinical trials.

Clinical trials have shown that AS03-adjuvanted H5N1 and A(H1N1)pdm09 vaccines are highly immunogenic, although with an increased reactogenicity profile relative to non-adjuvanted vaccines in terms of the incidence of common injection site and systemic adverse events (AEs). We evaluated pooled safety data from 22,521 adults who had received an AS03-adjuvanted H5N1 or A(H1N1)pdm09 influenza or control vaccine with the purpose to identify medically-attended AEs (MAEs), including subsets of serious AEs (SAEs), potentially immune-mediated diseases (pIMDs), and AEs of special interest (AESI), and to explore a potential association of these AEs with the administration of an AS03-adjuvanted influenza vaccine. For participants who had received an AS03-adjuvanted vaccine, the relative risks (RRs) for experiencing a MAE or a SAE compared to control group (participants who had received a non-adjuvanted vaccine or saline placebo) were 1.0 (95% confidence interval [CI]: 0.9; 1.1) and 1.1 (95% CI: 0.9; 1.4), respectively. The overall RRs for experiencing an AESI or a pIMD (AS03-adjuvanted vaccine/control) were 1.2 (95% CI: 0.9; 1.6) and 1.7 (95% CI: 0.8; 3.8), respectively. Thirty-8 participants in the AS03-adjuvanted vaccine group had a pIMD reported after vaccine administration, yielding an incidence rate (IR) of 351.9 (95% CI: 249.1; 483.1) per 100,000 person-years. The estimated IRs in the AS03-adjuvanted vaccine group were greater than the literature reported rates for: facial paresis/VIIth nerve paralysis, celiac disease, thrombocytopenia and ulcerative colitis. These results do not support an association between AS03-adjuvanted H5N1 and A(H1N1)pdm09 vaccines and the AEs collected in the trials included in the analysis.

Long-term outcome of the humoral and cellular immune response of an H5N1 adjuvanted influenza vaccine in elderly persons: 2-year follow-up of a randomised open-label study.

BACKGROUND: Older individuals often have a reduced immune response to influenza vaccination, which might be improved by administering a higher vaccine dose. We compared the immune response to two single doses of the AS03A-adjuvanted H5N1 pandemic vaccine (3.75 µg hemagglutinin of A/Vietnam/1194/2004) with that of two double vaccine doses (7.5 µg hemagglutinin) in adults aged ≥61 years. Here we report the 2-year persistence of the humoral and cellular immune response. METHODS: In this phase II, open-label study, healthy participants aged 61 to 88 years (median 68 years) were randomised (3:1:3:1) to receive two single doses of the AS03A-adjuvanted vaccine (1xH5N1-AS) or the non-adjuvanted vaccine (1xH5N1), or two double doses of the AS03A-adjuvanted vaccine (2xH5N1-AS) or the non-adjuvanted vaccine (2xH5N1), 21 days apart. Serum haemagglutination inhibition antibodies and cellular immune responses against A/Vietnam/1194/2004 were measured in all groups at months 12 and 24; neutralising antibodies were assessed in a subset of the adjuvanted groups. Serious adverse events and adverse events of specific interest were recorded. RESULTS: At month 24, haemagglutination inhibition antibody seroprotection rates were 37.2% (95% CI 27.0% to 48.3%) for 1xH5N1-AS, 30.9% (95% CI 21.1% to 42.1%) for 2xH5N1-AS, 16.2% (95% CI 6.2% to 32.0%) for 1xH5N1, and 8.3% (95% CI 1.0% to 27.0%) for 2xH5N1. Haemagglutination inhibition antibody geometric mean titres were 17.6 (95% CI 13.7 to 22.5) for 1xH5N1-AS, 18.4 (95% CI 14.2 to 23.8) for 2xH5N1-AS, 12.3 (95% CI 8.9 to 16.9) for 1xH5N1 and 9.8 (95% CI 6.7 to 14.4) for 2xH5N1. The median frequency of antigen-specific CD4+ T cells per 106 T cells (25th quartile; 75th quartile) was 852 (482; 1477) for 1xH5N1-AS, 1147 (662; 1698) for 2xH5N1-AS, 556 (343; 749) for 1x-H5N1 and 673 (465; 1497) for 2xH5N1. Neutralising antibody geometric mean titres were 391.0 (95% CI 295.5 to 517.5) in the 1xH5N1-AS group and 382.8 (95% CI 317.4 to 461.6) in the 2xH5N1-AS group. CONCLUSIONS: Antibody levels declined substantially in all groups. Seroprotection rates, geometric mean titres for haemagglutination inhibition antibodies, and CD4+ T-cell responses tended to be higher in the AS03A-adjuvanted groups. There was no clear benefit, in terms of long-term persistence of the immune response, of doubling the dose of the adjuvanted vaccine. No safety concern was observed up to 24 months post-primary vaccination. TRIAL REGISTRATION: NCT00397215 (7 November 2006).

Heterologous prime-boost vaccination using an AS03B-adjuvanted influenza A(H5N1) vaccine in infants and children<3 years of age.

BACKGROUND: Protecting young children from pandemic influenza should also reduce transmission to susceptible adults, including pregnant women. METHODS: An open study assessed immunogenicity and reactogenicity of a heterologous booster dose of A/turkey/Turkey/1/2005(H5N1)-AS03B (AS03B is an Adjuvant System containing α-tocopherol and squalene in an oil-in-water emulsion [5.93 mg tocopherol]) in infants and children aged 6 to <36 months that was given 6 months following 2-dose primary vaccination with A/Indonesia/05/2005(H5N1)-AS03B. Vaccines contained 1.9 µg of hemagglutinin antigen and AS03B. Hemagglutinin inhibition (HI) responses, microneutralization titers, and antineuraminidase antibody levels were assessed for 6 months following the booster vaccination. RESULTS: For each age stratum (defined on the basis of the subject's age at first vaccination as 6 to <12 months, 12 to <24 months, and 24 to <36 months) and overall (n=113), European influenza vaccine licensure criteria were fulfilled for responses to A/turkey/Turkey/1/2005(H5N1) 10 days following the booster vaccination. Local pain and fever increased with consecutive doses. Anamnestic immune responses were demonstrated for HI, neutralizing, and antineuraminidase antibodies against vaccine-homologous/heterologous strains. Antibody responses to vaccine-homologous/heterologous strains persisted in all children 6 months following the booster vaccination. CONCLUSIONS: Prevaccination of young children with a clade 2 strain influenza A(H5N1) AS03-adjuvanted vaccine followed by heterologous booster vaccination boosted immune responses to the homologous strain and a related clade, with persistence for at least 6 months. The results support a prime-boost vaccination approach in young children for pandemic influenza preparedness. CLINICAL TRIALS REGISTRATION: NCT01323946.

Long-term booster schedules with AS03A-adjuvanted heterologous H5N1 vaccines induces rapid and broad immune responses in Asian adults.

BACKGROUND: The pandemic potential of avian influenza A/H5N1 should not be overlooked, and the continued development of vaccines against these highly pathogenic viruses is a public health priority. METHODS: This open-label extension booster study followed a Phase III study of 1206 adults who had received two 3.75 µg doses of primary AS03A-adjuvanted or non-adjuvanted H5N1 split-virus vaccine (A/Vietnam/1194/2004; clade 1) (NCT00449670). The aim of the extension study was to evaluate different timings for heterologous AS03A-adjuvanted booster vaccination (A/Indonesia/5/2005; clade 2.1) given at Month 6, 12, or 36 post-primary vaccination. Immunogenicity was assessed 21 days after each booster vaccination and the persistence of immune responses against the primary vaccine strain (A/Vietnam) and the booster strain (A/Indonesia) was evaluated up to Month 48 post-primary vaccination. Reactogenicity and safety were also assessed. RESULTS: After booster vaccination given at Month 6, HI antibody responses to primary vaccine, and booster vaccine strains were markedly higher with one dose of AS03A-H5N1 booster vaccine in the AS03A-adjuvanted primary vaccine group compared with two doses of booster vaccine in the non-adjuvanted primary vaccine group. HI antibody responses were robust against the primary and booster vaccine strains 21 days after boosting at Month 12 or 36. At Month 48, in subjects boosted at Month 6, 12, or 36, HI antibody titers of ≥1:40 against the booster strain persisted in 39.2%, 61.2%, and 95.6% of subjects, respectively. Neutralizing antibody responses and cell-mediated immune responses also showed that AS03A-H5N1 heterologous booster vaccination elicited robust immune responses within 21 days of boosting at Month 6, 12, or 36 post-primary vaccination. The booster vaccine was well tolerated, and no safety concerns were raised. CONCLUSIONS: In Asian adults primed with two doses of AS03A-adjuvanted H5N1 pandemic influenza vaccine, strong cross-clade anamnestic antibody responses were observed after one dose of AS03A-H5N1 heterologous booster vaccine given at Month 6, 12, or 36 after priming, suggesting that AS03A-adjuvanted H5N1 vaccines may provide highly flexible prime-boost schedules. Although immunogenicity decreased with time, vaccinated populations could potentially be protected for up to three years after vaccination, which is likely to far exceed the peak of the a pandemic.

An assessment of prime-boost vaccination schedules with AS03A -adjuvanted prepandemic H5N1 vaccines: a randomized study in European adults.

BACKGROUND: Long-term persistence of immune response and safety of an H5N1 prepandemic influenza vaccine adjuvanted with AS03 (an α-tocopherol oil-in-water emulsion-based adjuvant system) was evaluated using various prime-boost schedules that mimicked potential pandemic scenarios (NCT00430521). METHODS: Five hundred and twelve healthy adults aged 18-60 years received primary vaccination with one or two doses (0, 21 days schedule) of the A/Vietnam/1194/2004 H5N1 vaccine followed by a booster dose (A/Vietnam/1194/2004 or A/Indonesia/05/2005 strain) six or twelve months later across eight randomized groups. Immunogenicity results by hemagglutination inhibition [HI] assay, microneutralization assay, and the cell-mediated immune response (CMI) are reported here for the four groups boosted at Month 12. RESULTS: A one-dose-adjuvanted primary administration followed 12 months later by a single-adjuvanted booster dose containing a heterologous vaccine strain met or exceeded all US and European criteria for both strains. Increasing the interval between the first and second dose (from 21 days to 12 months) resulted in stronger cross-reactive immune responses against the A/Indonesia/05/2005 strain. The HI antibody response against the two strains persisted for 6 months after the booster dose irrespective of the booster vaccine's strain. The neutralizing antibody responses and the CMI observed in the study population paralleled the HI immune response. Overall, the vaccine had a clinically acceptable safety profile. CONCLUSION: The H5N1 vaccine in this study allowed for flexibility in the time interval between primary and booster vaccination and the use of a heterologous strain without impacting the strength of the humoral and cellular immune response to both vaccine strains.

Safety and immunogenicity of a split-virion AS03A-adjuvanted A/Indonesia/05/2005 (H5N1) vaccine in Taiwanese adults.

BACKGROUND/PURPOSE: This study evaluated the immune response elicited by two formulations of an AS03(A)-adjuvanted H5N1 A/Indonesia/05/2005 prepandemic influenza vaccine, developed using manufacturing processes with or without thiomersal. In addition, it also evaluated compliance to the Centre for Biologics Evaluation and Research and Committee for Medicinal Products for Human Use (CHMP) immunogenicity guidance criteria for pandemic influenza vaccines in adults. METHODS: This phase III, observer-blind, randomized study (NCT00812981) enrolled 320 subjects aged 18-60 years into two groups to receive, 21 days apart, two doses of the formulation manufactured using either the thiomersal-containing process (Group TC) or the thiomersal-free process (Group TF). Blood samples collected before vaccination, 21 days after the second vaccine dose, and 6 months following the first vaccine dose (Days 0, 42, and 180) were analysed using a hemagglutination inhibition (HI) assay. Safety assessments were made for the entire study period. RESULTS: Twenty-one days after the second dose of vaccine, both groups met the CHMP criteria for vaccine-homologous HI response (seroprotection rates/seroconversion rates ≥ 98.7%, seroconversion factor ≥ 121.9) and also for a heterologous HI response against the A/Vietnam/1194/2004 strain (seroprotection rates/seroconversion rates ≥ 81.3%, seroconversion factor ≥ 10.8). Six months after the first dose of vaccine, a marked persistence of the vaccine-homologous HI response was observed that still met one or more CHMP criteria. Pain at the injection site (Group TF 95%, Group TC 91.8%) and myalgia (Group TF 68.8%, Group TC 63.5%) were the most frequently recorded solicited symptoms. Overall, both formulations had a clinically acceptable safety profile. CONCLUSION: Administration of two doses of the AS03(A)-adjuvanted H5N1 prepandemic influenza vaccine was found to be highly immunogenic in adults with a clinically acceptable safety profile. The ability to confer cross-clade protective immunity makes it a suitable option for mitigation of the morbidity and mortality of outbreaks and pandemics due to H5N1 and drifted strains.