Prospective cohort studies to evaluate the safety and immunogenicity of the 2013, 2014, and 2015 seasonal influenza vaccines produced by Instituto Butantan

Annual vaccination is the most effective way to prevent seasonal influenza illness. Instituto Butantan (IB) performed clinical studies with its 2013, 2014 and 2015 seasonal trivalent influenza vaccines (inactivated split-virion). Prospective cohort studies were carried out to describe the safety and immunogenicity of Instituto Butantan influenza vaccines, in healthy adults and elderly, from 2013 to 2015. Immediately after the informed consent was signed, participants underwent blood collection followed by vaccination. On study days 1, 2 and 3 post-vaccination participants were contacted by the staff to evaluate the occurrence of solicited (local and systemic) and non-solicited adverse reactions. On study day 21 (+7) subjects returned to the clinical site for final safety assessments and blood collection to evaluate post-vaccination immunogenicity. The immunogenicity analyses were performed by means of hemagglutination inhibition (HI) assay. The immunogenicity endpoints were: seroprotection (SPR) and seroconversion (SCR) rates and the geometric mean HI antibody titer ratio (GMTR). The 2013 study was conducted at the Centro de Referência para Imunobiológicos Especiais (CRIE) and at the Centro de Pesquisa Clínica do Instituto da Criança, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo while the 2014 and 2015 studies were conducted at CRIE. The vaccine composition followed the WHO recommendation for the Southern hemisphere seasonal influenza vaccine. Fortyseven healthy adults and 13 elderly participated in the 2013 study, 60 healthy adults and 60 elderly in the 2014 study, and 62 healthy adults and 57 elderly in the 2015 study. In the 2013, 2014 and 2015 studies, pain was the most frequent local adverse reaction and headache the most frequent systemic adverse reaction. All observed adverse reactions were classified as mild or moderate and none as severe. SPR >70% and SPR >60% were observed in adults and elderly, respectively, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. SCR >40% was observed in adults, for the three vaccine viruses, only in the 2014 study and SCR >30% was observed in the elderly, for the three vaccine viruses, only in the 2013 and 2014 studies. GMTR >2.5 among adults, for the three vaccine viruses was only observed in the 2013 study and GMTR >2.0 was observed among elderly, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. The 2013, 2014 and 2015 seasonal influenza vaccines produced by Instituto Butantan were safe and immunogenic according to the immunogenicity criteria defined by the European Medicines Agency (EMA)

Safety and immunogenicity of a seasonal trivalent inactivated influenza vaccine produced by Butantan Institute in 2013, 2014 e 2015

INTRODUÇÃO: A vacinação anual é recomendada como a medida mais efetiva contra a influenza sazonal. O Instituto Butantan (IB) realizou, anualmente, estudos clínicos das vacinas influenza sazonais trivalentes (fragmentada e inativada), produzidas em2013, 2014 e 2015. MÉTODO: Estudos de coorte prospectivos para descrever a imunogenicidade e a segurança da vacina influenza produzida pelo IB nos anos de 2013, 2014 e 2015 em participantes adultos saudáveis e idosos. Após assinatura do TCLE os participantes foram submetidos à coleta de sangue e receberam uma dose da vacina. Nos dias 1, 2 e 3 após a vacinação foram contatados para avaliação da segurança (reações adversas solicitadas locais e sistêmicas e não solicitadas). No dia 21(+7) pósvacinação retornaram ao centro de pesquisa para nova checagem da segurança e para a coleta de sangue para a avaliação da imunogenicidade pós-vacinação. As análises de imunogenicidade foram feitas através do método inibição de hemaglutinação (IH). Os desfechos de imunogenicidade foram: porcentagem de soroconversão (SC), porcentagem de soroproteção (SP) e razão da média geométrica dos títulos (RMGT) de anticorpos inibidores da hemaglutinação. O estudo de 2013 foi conduzido no Centro de Referência para Imunobiológicos Especiais (CRIE) e no Centro de Pesquisa Clínica do Instituto da Criança, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, os estudos de 2014 e 2015 foram realizados apenas no CRIE. As composições das vacinas utilizadas nos estudos em 2013, 2014 e 2015 seguiram as recomendações da OMS para vacina influenza sazonal do hemisfério sul. RESULTADOS: No ano de 2013, foram incluídos no estudo 47 adultos e 13 idosos, em 2014, 60 adultos e 60 idosos e em 2015, 62 adultos e 57 idosos. Nos estudos de 2013, 2014 e 2015, dor foi a reação adversa local mais frequente e cefaleia a sistêmica mais relatada. Todas as reações adversas observadas foram classificadas como leves ou moderadas e nenhuma como grave. Porcentagens de SP > 70% e >60% foram demonstradas para adultos e idosos, respectivamente, para os três vírus vacinais, nos estudos de 2013, 2014 e 2015. Porcentagem de SC > 40% foi demonstrada para os adultos, para os três vírus vacinais, apenas no estudo de 2014 e porcentagem de SC >30% foi demonstrada nos idosos, para os três vírus vacinais, apenas nos estudos de 2013 e 2014. RMGT > 2.5 nos adultos para os três vírus vacinais foi demonstrada apenas no estudo de 2013 e RMGT > 2 nos idosos, para os três vírus vacinais, foi demonstrada nos estudos de 2013, 2014 e 2015. CONCLUSÃO: As vacinas influenza sazonal de 2013, 2014 e 2015, produzidas integralmente pelo Instituto Butantan, foram seguras e imunogênicas segundo os parâmetros de imunogenicidade definidos pela EMAINTRODUCTION: Annual vaccination is most effective way to prevent seasonal influenza illness. Instituto Butantan (IB) performed clinical studies with its 2013, 2014 and 2015 seasonal trivalent influenza vaccines (split-virion and inactivated) METHODS: Prospective cohort studies to describe the safety and immunogenicity of Instituto Butantan influenza vaccine, in healthy adults and elderly, from 2013 to 2015. Soon after the informed consent was signed, participants underwent blood collection followed by vaccination. On study days 1, 2 and 3 post vaccination participants were contacted by the stuffy to evaluate the occurrence of solicited (local and systemic) and non-solicited adverse reactions. On study day 21(+7) subjects returned to the clinical site for final safety assessments and blood collection for the immunogenicity evaluation post vaccination. The immunogenicity analyses were performed by means of haemagglutination inhibition assay (HI). The immunogenicity endpoints were: seroprotection (SPR) and seroconversion (SCR) rates and the geometric mean HI antibody titer ratio (GMTR). The 2013 study The Centro de Referência para Imunobiológicos Especiais (CRIE) and at the Centro de Pesquisa Clínica do Instituto da Criança, Hospital das Clínicas of Medical School of University of São Paulo and the 2014 and 2015 studies were conducted at CRIE. The vaccine composition followed the WHO recommendation for the southern hemisphere seasonal influenza vaccine RESULTS: 47 healthy adults and 13 elderly participated in the 2013 study, 60 healthy adults and 60 elderly in the 2014 study, and 62 healthy adults and 57 elderly in the 2015 study. In the 2013, 2014 and 2015 studies, pain was the most frequent local adverse reaction and headache the most frequent systemic adverse reaction. All observed adverse reactions were classified as mild or moderate and none as severe. SPR > 70% and SPR > 60% were observed in adults and elderly, respectively, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. SCR > 40% was observed in adults, for the three vaccine viruses, only in the 2014 study and SCR > 30% was observed in elderly, for the three vaccine viruses, only in the 2013 and 2014 studies. GMTR >2.5 among adults, for the three vaccine viruses was only observed in the 2013 study and GMTR > 2.0 was observed among elderly, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. CONCLUSION: The 2013, 2014 and 2015 seasonal influenza vaccines produced by Instituto Butantan were safe and immunogenic according to the immunogenicity criteria defined by EM

Safety and immunogenicity of a seasonal trivalent inactivated influenza vaccine produced by Butantan Institute in 2013, 2014 e 2015

INTRODUÇÃO: A vacinação anual é recomendada como a medida mais efetiva contra a influenza sazonal. O Instituto Butantan (IB) realizou, anualmente, estudos clínicos das vacinas influenza sazonais trivalentes (fragmentada e inativada), produzidas em2013, 2014 e 2015. MÉTODO: Estudos de coorte prospectivos para descrever a imunogenicidade e a segurança da vacina influenza produzida pelo IB nos anos de 2013, 2014 e 2015 em participantes adultos saudáveis e idosos. Após assinatura do TCLE os participantes foram submetidos à coleta de sangue e receberam uma dose da vacina. Nos dias 1, 2 e 3 após a vacinação foram contatados para avaliação da segurança (reações adversas solicitadas locais e sistêmicas e não solicitadas). No dia 21(+7) pósvacinação retornaram ao centro de pesquisa para nova checagem da segurança e para a coleta de sangue para a avaliação da imunogenicidade pós-vacinação. As análises de imunogenicidade foram feitas através do método inibição de hemaglutinação (IH). Os desfechos de imunogenicidade foram: porcentagem de soroconversão (SC), porcentagem de soroproteção (SP) e razão da média geométrica dos títulos (RMGT) de anticorpos inibidores da hemaglutinação. O estudo de 2013 foi conduzido no Centro de Referência para Imunobiológicos Especiais (CRIE) e no Centro de Pesquisa Clínica do Instituto da Criança, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, os estudos de 2014 e 2015 foram realizados apenas no CRIE. As composições das vacinas utilizadas nos estudos em 2013, 2014 e 2015 seguiram as recomendações da OMS para vacina influenza sazonal do hemisfério sul. RESULTADOS: No ano de 2013, foram incluídos no estudo 47 adultos e 13 idosos, em 2014, 60 adultos e 60 idosos e em 2015, 62 adultos e 57 idosos. Nos estudos de 2013, 2014 e 2015, dor foi a reação adversa local mais frequente e cefaleia a sistêmica mais relatada. Todas as reações adversas observadas foram classificadas como leves ou moderadas e nenhuma como grave. Porcentagens de SP > 70% e >60% foram demonstradas para adultos e idosos, respectivamente, para os três vírus vacinais, nos estudos de 2013, 2014 e 2015. Porcentagem de SC > 40% foi demonstrada para os adultos, para os três vírus vacinais, apenas no estudo de 2014 e porcentagem de SC >30% foi demonstrada nos idosos, para os três vírus vacinais, apenas nos estudos de 2013 e 2014. RMGT > 2.5 nos adultos para os três vírus vacinais foi demonstrada apenas no estudo de 2013 e RMGT > 2 nos idosos, para os três vírus vacinais, foi demonstrada nos estudos de 2013, 2014 e 2015. CONCLUSÃO: As vacinas influenza sazonal de 2013, 2014 e 2015, produzidas integralmente pelo Instituto Butantan, foram seguras e imunogênicas segundo os parâmetros de imunogenicidade definidos pela EMAINTRODUCTION: Annual vaccination is most effective way to prevent seasonal influenza illness. Instituto Butantan (IB) performed clinical studies with its 2013, 2014 and 2015 seasonal trivalent influenza vaccines (split-virion and inactivated) METHODS: Prospective cohort studies to describe the safety and immunogenicity of Instituto Butantan influenza vaccine, in healthy adults and elderly, from 2013 to 2015. Soon after the informed consent was signed, participants underwent blood collection followed by vaccination. On study days 1, 2 and 3 post vaccination participants were contacted by the stuffy to evaluate the occurrence of solicited (local and systemic) and non-solicited adverse reactions. On study day 21(+7) subjects returned to the clinical site for final safety assessments and blood collection for the immunogenicity evaluation post vaccination. The immunogenicity analyses were performed by means of haemagglutination inhibition assay (HI). The immunogenicity endpoints were: seroprotection (SPR) and seroconversion (SCR) rates and the geometric mean HI antibody titer ratio (GMTR). The 2013 study The Centro de Referência para Imunobiológicos Especiais (CRIE) and at the Centro de Pesquisa Clínica do Instituto da Criança, Hospital das Clínicas of Medical School of University of São Paulo and the 2014 and 2015 studies were conducted at CRIE. The vaccine composition followed the WHO recommendation for the southern hemisphere seasonal influenza vaccine RESULTS: 47 healthy adults and 13 elderly participated in the 2013 study, 60 healthy adults and 60 elderly in the 2014 study, and 62 healthy adults and 57 elderly in the 2015 study. In the 2013, 2014 and 2015 studies, pain was the most frequent local adverse reaction and headache the most frequent systemic adverse reaction. All observed adverse reactions were classified as mild or moderate and none as severe. SPR > 70% and SPR > 60% were observed in adults and elderly, respectively, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. SCR > 40% was observed in adults, for the three vaccine viruses, only in the 2014 study and SCR > 30% was observed in elderly, for the three vaccine viruses, only in the 2013 and 2014 studies. GMTR >2.5 among adults, for the three vaccine viruses was only observed in the 2013 study and GMTR > 2.0 was observed among elderly, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. CONCLUSION: The 2013, 2014 and 2015 seasonal influenza vaccines produced by Instituto Butantan were safe and immunogenic according to the immunogenicity criteria defined by EM

Prospective cohort studies to evaluate the safety and immunogenicity of the 2013, 2014, and 2015 seasonal influenza vaccines produced by Instituto Butantan

ABSTRACT Annual vaccination is the most effective way to prevent seasonal influenza illness. Instituto Butantan (IB) performed clinical studies with its 2013, 2014 and 2015 seasonal trivalent influenza vaccines (inactivated split-virion). Prospective cohort studies were carried out to describe the safety and immunogenicity of Instituto Butantan influenza vaccines, in healthy adults and elderly, from 2013 to 2015. Immediately after the informed consent was signed, participants underwent blood collection followed by vaccination. On study days 1, 2 and 3 post-vaccination participants were contacted by the staff to evaluate the occurrence of solicited (local and systemic) and non-solicited adverse reactions. On study day 21 (+7) subjects returned to the clinical site for final safety assessments and blood collection to evaluate post-vaccination immunogenicity. The immunogenicity analyses were performed by means of hemagglutination inhibition (HI) assay. The immunogenicity endpoints were: seroprotection (SPR) and seroconversion (SCR) rates and the geometric mean HI antibody titer ratio (GMTR). The 2013 study was conducted at the Centro de Referência para Imunobiológicos Especiais (CRIE) and at the Centro de Pesquisa Clínica do Instituto da Criança, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo while the 2014 and 2015 studies were conducted at CRIE. The vaccine composition followed the WHO recommendation for the Southern hemisphere seasonal influenza vaccine. Forty-seven healthy adults and 13 elderly participated in the 2013 study, 60 healthy adults and 60 elderly in the 2014 study, and 62 healthy adults and 57 elderly in the 2015 study. In the 2013, 2014 and 2015 studies, pain was the most frequent local adverse reaction and headache the most frequent systemic adverse reaction. All observed adverse reactions were classified as mild or moderate and none as severe. SPR >70% and SPR >60% were observed in adults and elderly, respectively, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. SCR >40% was observed in adults, for the three vaccine viruses, only in the 2014 study and SCR >30% was observed in the elderly, for the three vaccine viruses, only in the 2013 and 2014 studies. GMTR >2.5 among adults, for the three vaccine viruses was only observed in the 2013 study and GMTR >2.0 was observed among elderly, for the three vaccine viruses, in the 2013, 2014 and 2015 studies. The 2013, 2014 and 2015 seasonal influenza vaccines produced by Instituto Butantan were safe and immunogenic according to the immunogenicity criteria defined by the European Medicines Agency (EMA)

Detection of anti-IFI16 antibodies by ELISA: clinical and serological associations in systemic sclerosis.

Objectives: To validate the clinical significance of anti-IFI16 autoantibodies in SSc and assess their associations with serological markers of SSc. Methods: A semi-quantitative ELISA was used to detect anti-IFI16 autoantibodies in the sera of 344 SSc patients from seven Italian hospitals and 144 healthy controls. SSc-associated autoantibodies [anti-RNA polymerase III (anti-RNAP III) antibodies, anti-centromere, anti-topo I] and IF patterns were evaluated using commercial assays. Statistical analyses were performed to test clinical and serological associations. Results: The results of this study confirm a significant prevalence (29%) of anti-IFI16 antibodies in the SSc population (n = 344). Anti-IFI16 antibodies were also detected in 30% of the SSc patients who tested negative for both ACAs and anti-topo I (anti-Scl70) antibodies. In this subgroup of patients, anti-IFI16 antibodies were significantly associated with the limited cutaneous form of SSc with a sensitivity of 40% and a specificity of 81%. Moreover, analysis of the distribution of anti-RNAP III antibodies vs anti-IFI16 in the same SSc population showed that they were mutually exclusive. IIF revealed no association between anti-IFI16 and fluoroscopic patterns, due to a lack of IFI16 autoantigen in HEp-2 cells. Anti-IFI16 antibody levels were also significantly associated with heart involvement. Conclusions: Anti-IFI16 autoantibodies are frequently detected in SSc, displaying clinical and laboratory associations, and being particularly useful for diagnosis and disease classification in patients who are negative for other SSc serological markers

A phase I randomized, double-blind, controlled trial of 2009 influenza A (H1N1) inactivated monovalent vaccines with different adjuvant systems

Methods\ud \ud We conducted a phase I, multicenter, randomized, double-blind, placebo-controlled, multi-arm (10) parallel study involving healthy adults to evaluate the safety and immunogenicity of influenza A (H1N1) 2009 non-adjuvanted and adjuvanted candidate vaccines. Subjects received two intramuscular injections of one of the candidate vaccines administered 21 days apart. Antibody responses were measured by means of hemagglutination-inhibition assay before and 21 days after each vaccination. The three co-primary immunogenicity end points were the proportion of seroprotection >70%, seroconversion >40%, and the factor increase in the geometric mean titer >2.5.\ud Results\ud \ud A total of 266 participants were enrolled into the study. No deaths or serious adverse events were reported. The most commonly solicited local and systemic adverse events were injection-site pain and headache, respectively. Only three subjects (1.1%) reported severe injection-site pain. Four 2009 influenza A (H1N1) inactivated monovalent candidate vaccines that met the three requirements to evaluate influenza protection, after a single dose, were identified: 15 μg of hemagglutinin antigen without adjuvant; 7.5 μg of hemagglutinin antigen with aluminum hydroxide, MPL and squalene; 3.75 μg of hemagglutinin antigen with aluminum hydroxide and MPL; and 3.75 μg of hemagglutinin antigen with aluminum hydroxide and squalene.\ud Conclusions\ud \ud Adjuvant systems can be safely used in influenza vaccines, including the adjuvant monophosphoryl lipid A (MPL) derived from Bordetella pertussis with squalene and aluminum hydroxide, MPL with aluminum hydroxide, and squalene and aluminum hydroxide.This study was funded by the Butantan Foundation

A phase I randomized, double-blind, controlled trial of 2009 influenza A (H1N1) inactivated monovalent vaccines with different adjuvant systems

Methods\ud \ud We conducted a phase I, multicenter, randomized, double-blind, placebo-controlled, multi-arm (10) parallel study involving healthy adults to evaluate the safety and immunogenicity of influenza A (H1N1) 2009 non-adjuvanted and adjuvanted candidate vaccines. Subjects received two intramuscular injections of one of the candidate vaccines administered 21 days apart. Antibody responses were measured by means of hemagglutination-inhibition assay before and 21 days after each vaccination. The three co-primary immunogenicity end points were the proportion of seroprotection >70%, seroconversion >40%, and the factor increase in the geometric mean titer >2.5.\ud Results\ud \ud A total of 266 participants were enrolled into the study. No deaths or serious adverse events were reported. The most commonly solicited local and systemic adverse events were injection-site pain and headache, respectively. Only three subjects (1.1%) reported severe injection-site pain. Four 2009 influenza A (H1N1) inactivated monovalent candidate vaccines that met the three requirements to evaluate influenza protection, after a single dose, were identified: 15 μg of hemagglutinin antigen without adjuvant; 7.5 μg of hemagglutinin antigen with aluminum hydroxide, MPL and squalene; 3.75 μg of hemagglutinin antigen with aluminum hydroxide and MPL; and 3.75 μg of hemagglutinin antigen with aluminum hydroxide and squalene.\ud Conclusions\ud \ud Adjuvant systems can be safely used in influenza vaccines, including the adjuvant monophosphoryl lipid A (MPL) derived from Bordetella pertussis with squalene and aluminum hydroxide, MPL with aluminum hydroxide, and squalene and aluminum hydroxide.This study was funded by the Butantan Foundation

Active pharmacovigilance of the seasonal trivalent influenza vaccine produced by Instituto Butantan: A prospective cohort study of five target groups.

IntroductionActive pharmacovigilance studies are pivotal to better characterize vaccine safety.MethodsThese are multicenter prospective cohort studies to evaluate the safety of the 2017 and 2018 seasonal trivalent influenza vaccines (TIVs) manufactured by Instituto Butantan, by means of active pharmacovigilance practices. Elderly, children, healthcare workers, pregnant women, and women in the puerperium period were invited to participate in the study during the 2017 and 2018 Brazilian national seasonal influenza vaccination campaigns. Following immunization, participants were observed for 30 minutes and they received a participant card to register adverse events information. All safety information registered were checked at a clinical site visit 14 days after immunization and by a telephone contact 42 days after immunization for unsolicited Adverse Events (AE) and Guillain-Barré Syndrome (GBS).ResultsA total of 942 volunteers participated in the two studies: 305 elderly, 109 children, 108 pregnant women, 32 women in the postpartum period, and 388 health workers. Overall, the median number of AR per participant ranged from 1 to 4. The lowest median number of AR per participant was observed among healthcare workers (1 AR per participant) and the highest among pregnant women (4 AR per participant). Overall, local pain (46.6%) was the most frequent solicited local AR. The most frequent systemic ARs were: headache (22.5%) followed by fatigue (16.0%), and malaise (11.0%). The majority of solicited ARs (96%) were mild, Grades 1 or 2), only 3% were Grade 3, and 1% was Grade 4. No serious AEs, including Guillain-Barré Syndrome, were reported up to 42 days postvaccination.ConclusionThe results from the two studies confirmed that the 2017 and 2018 seasonal trivalent influenza vaccines produced by Instituto Butantan were safe and that active pharmacovigilance studies should be considered, when it is feasible, as an important initiative to monitor vaccine safety in the post-marketing period

Dose-sparing effect of two adjuvant formulations with a pandemic influenza A/H7N9 vaccine: A randomized, double-blind, placebo-controlled, phase 1 clinical trial.

The emergence of potentially pandemic viruses has resulted in preparedness efforts to develop candidate vaccines and adjuvant formulations. We evaluated the dose-sparing effect and safety of two distinct squalene-based oil-in-water adjuvant emulsion formulations (IB160 and SE) with influenza A/H7N9 antigen. This phase I, randomized, double-blind, placebo-controlled, dose-finding trial (NCT03330899), enrolled 432 healthy volunteers aged 18 to 59. Participants were randomly allocated to 8 groups: 1A) IB160 + 15μg H7N9, 1B) IB160 + 7.5μg H7N9, 1C) IB160 + 3.75μg H7N9, 2A) SE + 15μg H7N9, 2B) SE + 7.5μg H7N9, 2C) SE + 3.75μg H7N9, 3) unadjuvanted vaccine 15μg H7N9 and 4) placebo. Immunogenicity was evaluated through haemagglutination inhibition (HI) and microneutralization (MN) tests. Safety was evaluated by monitoring local and systemic, solicited and unsolicited adverse events (AE) and reactions (AR) 7 and 28 days after each study injection, respectively, whereas serious adverse events (SAE) were monitored up to 194 days post-second dose. A greater increase in antibody geometric mean titers (GMT) was observed in groups receiving adjuvanted vaccines. Vaccinees receiving IB160-adjuvanted formulations showed the greatest response in group 1B, which induced an HI GMT increase of 4.7 times, HI titers ≥40 in 45.2% of participants (MN titers ≥40 in 80.8%). Vaccinees receiving SE-adjuvanted vaccines showed the greatest response in group 2A, with an HI GMT increase of 2.5 times, HI titers ≥40 in 22.9% of participants (MN titers ≥40 in 65.7%). Frequencies of AE and AR were similar among groups. Pain at the administration site and headache were the most frequent local and systemic solicited ARs. The vaccine candidates were safe and the adjuvanted formulations have a potential dose-sparing effect on immunogenicity against influenza A/H7N9. The magnitude of this effect could be further explored