Effects of adjuvants on the safety and immunogenicity of an avian influenza H5N1 vaccine in adults

BACKGROUND: Influenza A H5N1 viruses pose a significant threat to human health. METHODS: We conducted a multicenter, randomized, double-blind study in 394 healthy adults. Subjects were randomly assigned to receive 2 intramuscular doses of either saline placebo; influenza A/Vietnam/1203/2004(H5N1) vaccine alone at 45, 30, or 15 microg per dose; vaccine at 15 or 7.5 microg per dose with MF59; or vaccine at 30, 15, or 7.5 microg per dose with aluminum hydroxide. Subjects were followed up for safety and blood samples were obtained to determine antibody responses. RESULTS: The vaccine formulations were well tolerated but local adverse effects were common; the incidence of these effects increased in a dose-dependent manner and was increased by the addition of adjuvants. The addition of MF59 increased the antibody response, whereas the addition of aluminum hydroxide did not. The highest antibody responses were seen in the group that received 15 microg of vaccine per dose with MF59, in which 63% of subjects achieved the predetermined endpoint (hemagglutination-inhibition titer > or =40) 28 days after the second dose, compared with 29% in the group that received the highest dose (45 microg per dose) of vaccine alone. CONCLUSIONS: A 2-dose regimen of subvirion influenza A (H5N1) vaccine was well tolerated. The antibody responses to 15 microg of A/H5 vaccine with MF59 were higher than the responses to 45 microg of vaccine alone. TRIAL REGISTRATION: ClincalTrials.gov identifier: http://www.clinicaltrials.gov/ct2/show/NCT00280033?term= NCT00280033&rank=1 NCT00280033 .     

An adjuvanted, low-dose, pandemic influenza A (H5N1) vaccine candidate is safe, immunogenic, and induces cross-reactive immune responses in healthy adults

BACKGROUND: To protect a naive global population against pandemic influenza, pandemic vaccines should be effective at low antigen doses, because of limited manufacturing capacity. METHODS: In a multicenter, randomized, blind-observer phase 1 trial, groups of 50 healthy young adults received 2 doses, 21 days apart, of influenza A/Vietnam/1194/2004 NIBRG-14 (H5N1) vaccine containing 1.9, 3.8, 7.5 or 15 microg of hemagglutinin with oil-in-water emulsion adjuvant or 7.5 microg of hemagglutinin without adjuvant. Safety was monitored to day 42. Homologous hemagglutination-inhibition (HI) and microneutralization titers were determined after each vaccination. Cross-reactivity against A/Indonesia/05/2005 RG2 was tested after the second vaccination. RESULTS: No vaccine-related significant or serious adverse events occurred. Injection site reactions, but not systemic reactions, were more frequent with adjuvant than without. Even with only 1.9 microg of hemagglutinin plus adjuvant, 72% of subjects had HI titers >or=1:32 after 2 doses. This proportion was 81%-89% with higher adjuvanted doses but was only 34% without adjuvant. Adjuvanted vaccine induced cross-neutralizing antibodies in 39%-65% of samples, versus 7% without adjuvant. CONCLUSIONS: The emulsion-adjuvanted pandemic influenza vaccine candidate was safe, immunogenic, and induced cross-reactive antibodies. This adjuvanted 1.9-microg candidate is the lowest effective dose tested to date. This could have a major impact on prepandemic vaccination strategies with stockpiled batches of vaccine. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00457509 .     

Safety and immunogenicity of an inactivated influenza A/H5N1 vaccine given with or without aluminum hydroxide to healthy adults: results of a phase I-II randomized clinical trial

BACKGROUND: Dose-sparing strategies are being explored for vaccines against pandemic influenza. We evaluated the dose-sparing potential of aluminum hydroxide (AlOH) adjuvant. METHODS: A total of 600 healthy subjects (age, 18-49 years) were randomized to receive 2 vaccinations 1 month apart with subvirion inactivated influenza A/H5N1 vaccine containing 7.5, 15, or 45 microg of hemagglutinin (HA), with or without 600 microg of aluminum hydroxide (AlOH), or 3.75 microg of HA, with or without 300 microg of AlOH. Serum specimens were obtained for antibody assays before and 1 month after each vaccination. RESULTS: All formulations were safe. Injection site discomfort was more frequent in groups given vaccines with AlOH. Dose-related increases in antibody responses were noted after both vaccinations (P< .001) geometric mean titers of hemagglutination inhibition antibody in vaccines with and without AlOH, respectively, were 5.4 and 5.4 for subjects who received 3.75 microg of HA, 7.7 and 5.3 for those who received 7.5 microg of HA, 8.1 and 8.5 for those who received 15 microg of HA, and 14.8 and 12 for those who received 45 microg of HA. A > or =4-fold increase in titer was observed in 2% and 2% of subjects who received 3.75 microg of HA with or without AlOH, respectively; in 14% and 0% who received 7 microg of HA; in 14% and 13% who received 15 microg of HA; and in 33% and 25% who received 45 microg of HA. Addition of AlOH enhanced responses only for subjects who received 7.5 microg of HA, but responses in subjects who received 7.5 microg of HA without AlOH were unexpectedly low. CONCLUSION: Overall, a meaningful beneficial effect of AlOH adjuvant was not observed. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00296634 .     

148名医务人员接种甲型H_1N_1流行性感冒病毒裂解灭活疫苗后的免疫原性和安全性分析

目的:通过分析疫苗接种后的不良反应和检测疫苗接种前后血清抗体滴度,评估甲型H1N1流行性感冒(流感)病毒裂解灭活疫苗的安全性和免疫原性。方法:研究纳入148名医务人员,描述性分析疫苗接种后21 d内发生的不良反应并评估其严重程度;通过血凝抑制试验检测疫苗接种后血清抗体滴度。结果:该疫苗接种后绝大多数不良反应为轻、中度,未见严重不良反应事件。局部不良反应和全身不良反应发生率分别为19.1%和22.1%,接种部位疼痛和乏力是最常见的局部和全身不良反应。接种疫苗后21 d,血清抗体平均效价达1∶95.27[95%可信区间(CI):74.94～121.12)],101名接种者(82.1%,101/123)血清抗体滴度达到1∶40或高于1∶40,74.0%在疫苗接种后21 d血清抗体转阳。结论:对于成人甲型H1N1流感病毒裂解灭活疫苗可安全接种;绝大多数在接种后21 d血清抗体可转阳。     

Characterization of a whole,inactivated influenza (H5N1) vaccine

Objectives Effective vaccines against the highly pathogenic influenza A/H5N1 virus are being developed worldwide. In Japan, two adjuvanted, inactivated, whole‐virion influenza vaccines were recently developed and licensed as mock‐up, pre‐pandemic vaccine formulations by the Ministry of Health and Labor Welfare of Japan. During the vaccine design and development process, various obstacles were overcome and, in this report, we introduce the non clinical production, immunogenicity data in human and development process that was associated with egg‐derived adjuvanted, inactivated, whole‐virion influenza A (H5N1) vaccine. Design Pilot lots of H5N1 vaccine were produced using the avirulent H5N1 reference strain A/Vietnam/1194/2004 (H5N1) NIBRG‐14 and administered following adsorption with aluminum hydroxide as an adjuvant. Quality control and formulation stability tests were performed before clinical trials were initiated (phase I‐III).
The research foundation for microbial diseases of Osaka University (BIKEN) carried out vaccine production, quality control, stability testing and the phase I clinical trial in addition to overseeing the licensing of this vaccine. Mitsubishi Chemical Safety Institute Ltd. carried out the non clinical pharmacological toxicity and safety studies and the Japanese medical association carried out the phase II/III trials. Phase I‐III trials took place in 2006. Results The production processes were well controlled by established tests and validations. Vaccine quality was confirmed by quality control, stability and pre‐clinical tests, and the vaccine was approved as a mock‐up, pre‐pandemic vaccine by the Ministry of Health and Labor Welfare of Japan. Conclusions Numerous safety and efficacy procedures were carried out prior to the approval of the described vaccine formulation. Some of these procedures were of particular importance e.g., vaccine development, validation, and quality control tests that included strict monitoring of the hemagglutinin (HA) content of the vaccine formulations.
Improving vaccine productivity, shortening the production period and improving antigen yield of the avirulent vaccine strains were also considered important vaccine development criteria.     

Safety and immunogenicity of live attenuated influenza reassortant H5 vaccine (phase I–II clinical trials)

Objective Our studies aimed to evaluate in clinical trials the safety and immunogenicity of an H5 live influenza vaccine candidate obtained using classical reassortment techniques from a low pathogenicity avian influenza (LPAI) A/Duck/Potsdam/1402‐6/86(H5N2) virus and the cold‐adapted (ca) donor strain A/Leningrad/134/17/57(H2N2). Methods During Phase I–II clinical trials, volunteers received intranasally two doses of reassortant influenza vaccine strain A/17/Duck/Potsdam/86/92 (H5N2) 21 days apart. Clinical examination of all vaccinees was conducted 7 days post‐vaccination. Serum antibody responses were measured by hemagglutination‐inhibition and microneutralization and local antibodies were estimated using an enzyme‐linked immunosorbent assay test. Results The vaccine was safe and of low reactogenicity with no febrile reactions. After revaccination 47·1–54·8% of subjects showed ≥fourfold seroconversions of Hamagglutination inhibition (HAI) antibodies to the hemagglutinin (HA) antigen of the A/17/Duck/Potsdam/86/92 (H5N2) virus and 29·4–30·8% were seroconverted to the HA antigen of the reverse genetics reassortant A/Indonesia/05/2005 × PR8 IBCDC‐RG (H5N1). Virus‐neutralizing antibody levels in sera of volunteers were similar to those shown in HAI test. The virus‐specific nasal IgA antibody response after two vaccine doses demonstrated significant increases of ≥fourfold rise SIgA antibodies (65%) geometrical mean titers (16·0) and a rise in SIgA antibodies (2·8) compared with one dose. Conclusion The live attenuated influenza vaccine candidate prepared using the LPAI A(H5N2) strain was well tolerated and elicited serum and local immune responses. There was evident cross‐reactivity to the A(H5N1) strain in the HAI test.     

Evaluation of the safety and immunogenicity of a booster (third) dose of inactivated subvirion H5N1 influenza vaccine in humans

Previously, we evaluated 2 doses of H5N1 influenza vaccine in persons 18-64 years of age (placebo and 7.5-, 15-, 45-, or 90-microg doses), separated by 28 days. In this study, 337 participants received a third dose, 6 months thereafter. Microneutralization (MN) and hemagglutination-inhibition geometric mean titers (GMTs) of antibody declined before the third dose. Twenty-eight days after the third dose, 78%, 67%, 43%, and 31% of recipients in the 90-, 45-, 15-, and 7.5-mug-dose groups had a MN GMT > or =1:40, respectively. Five months later, MN GMTs were significantly greater than those after the second dose. (Trial registration: Clinical Trials.gov identifier NCT00240968 .).     

Comparative safety, immunogenicity, and efficacy of several anti-H5N1 influenza experimental vaccines in a mouse and chicken models (Testing of killed and live H5 vaccine)

Please cite this paper as: Gambaryan et al. (2011) Comparative safety, immunogenicity, and efficacy of several anti‐H5N1 influenza experimental vaccines in a mouse and chicken models. Parallel testing of killed and live H5 vaccine. Influenza and Other Respiratory Viruses 6(3), 188–195. Objective Parallel testing of inactivated (split and whole virion) and live vaccine was conducted to compare the immunogenicity and protective efficacy against homologous and heterosubtypic challenge by H5N1 highly pathogenic avian influenza virus. Method Four experimental live vaccines based on two H5N1 influenza virus strains were tested; two of them had hemagglutinin (HA) of A/Vietnam/1203/04 strain lacking the polybasic HA cleavage site, and two others had hemagglutinins from attenuated H5N1 virus A/Chicken/Kurgan/3/05, with amino acid substitutions of Asp54/Asn and Lys222/Thr in HA1 and Val48/Ile and Lys131/Thr in HA2 while maintaining the polybasic HA cleavage site. The neuraminidase and non‐glycoprotein genes of the experimental live vaccines were from H2N2 cold‐adapted master strain A/Leningrad/134/17/57 (VN‐Len and Ku‐Len) or from the apathogenic H6N2 virus A/Gull/Moscow/3100/2006 (VN‐Gull and Ku‐Gull). Inactivated H5N1 and H1N1 and live H1N1 vaccine were used for comparison. All vaccines were applied in a single dose. Safety, immunogenicity, and protectivity against the challenge with HPAI H5N1 virus A/Chicken/Kurgan/3/05 were estimated. Results All experimental live H5 vaccines tested were apathogenic as determined by weight loss and conferred more than 90% protection against lethal challenge with A/Chicken/Kurgan/3/05 infection. Inactivated H1N1 vaccine in mice offered no protection against challenge with H5N1 virus, while live cold‐adapted H1N1 vaccine reduced the mortality near to zero level. Conclusions The high yield, safety, and protectivity of VN‐Len and Ku‐Len made them promising strains for the production of inactivated and live vaccines against H5N1 viruses.