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1.
PLoS One ; 17(10): e0274943, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36256646

RESUMO

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.


Assuntos
Subtipo H7N9 do Vírus da Influenza A , Vacinas contra Influenza , Influenza Humana , Humanos , Esqualeno , Pandemias/prevenção & controle , Polissorbatos , Emulsões , Anticorpos Antivirais , Testes de Inibição da Hemaglutinação , Adjuvantes Imunológicos , Adjuvantes Farmacêuticos , Água
2.
Vaccine ; 40(14): 2140-2149, 2022 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-35248422

RESUMO

While the degree of COVID-19 vaccine accessibility and uptake varies at both national and global levels, increasing vaccination coverage raises questions regarding the standard of prevention that ought to apply to different settings where COVID-19 vaccine trials are hosted. A WHO Expert Group has developed guidance on the ethical implications of conducting placebo-controlled trials in the context of expanding global COVID-19 vaccine coverage. The guidance also considers alternative trial designs to placebo controlled trials in the context of prototype vaccines, modified vaccines, and next generation vaccines.


Assuntos
COVID-19 , Vacinas , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , SARS-CoV-2 , Organização Mundial da Saúde
3.
AIDS ; 36(1): 95-105, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34581306

RESUMO

BACKGROUND: Elite controllers are therapy-naive individuals living with HIV capable of spontaneous control of plasma viraemia for at least a year. Although viremic nonprogressors are more common in vertical HIV-infection than in adults' infection, elite control has been rarely characterized in the pediatric population. DESIGN: We analyzed the T-cell immunophenotype and the HIV-specific response by flow cytometry in four pediatric elite controllers (PECs) compared with age-matched nonprogressors (PNPs), progressors and HIV-exposed uninfected (HEUs) adolescents. RESULTS: PECs T-cell populations had lower immune activation and exhaustion levels when compared with progressors, reflected by a more sustained and preserved effector function. The HIV-specific T-cell responses among PECs were characterized by high-frequency Gag-specific CD4+ T-cell activity, and markedly more polyfunctional Gag-specific CD8+ activity, compared with PNPs and progressors. These findings were consistently observed even in the absence of protective HLA-I molecules such as HLA-B∗27/57/81. CONCLUSION: Pediatric elite control is normally achieved after years of infection, and low immune activation in PNPs precedes the increasing ability of CD8+ T-cell responses to achieve immune control of viraemia over the course of childhood, whereas in adults, high immune activation in acute infection predicts subsequent CD8+ T-cell mediated immune control of viremia, and in adult elite controllers, low immune activation is therefore the consequence of the rapid CD8+ T-cell mediated immune control generated after acute infection. This distinct strategy adopted by PECs may help identify pathways that facilitate remission in posttreatment controllers, in whom protective HLA-I molecules are not the main factor.


Assuntos
Infecções por HIV , HIV-1 , Adolescente , Adulto , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Criança , Humanos , Carga Viral , Viremia
4.
PloS One ; 17(10): e0274943, 2022.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-4565

RESUMO

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.

6.
Wellcome Open Res ; 6: 17, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33693063

RESUMO

As the world reflects upon one year since the first cases of coronavirus disease 2019 (COVID-19) and prepare for and experience surges in cases, it is important to identify the most crucial ethical issues that might lie ahead so that countries are able to plan accordingly. Some ethical issues are rather obvious to predict, such as the ethical issues surrounding the use of immunity certificates, contact tracing, and the fair allocation of vaccines globally. Yet, the most significant ethical challenge that the world must address in the next year and beyond is to ensure that we learn the ethical lessons of the first year of this pandemic. Learning from our collective experiences thus far constitutes our greatest moral obligation. Appreciating that decision-making in the context of a pandemic is constrained by unprecedented complexity and uncertainty, beginning in June 2020, an international group of 17 experts in bioethics spanning 15 countries (including low-, middle-, and high-income countries) met virtually to identify what we considered to be the most significant ethical challenges and accompanying lessons faced thus far in the COVID-19 pandemic. Once collected, the group met over the course of several virtual meetings to identify challenges and lessons that are analytically distinct in order to identify common ethical themes under which different challenges and lessons could be grouped. The result, described in this paper, is what this expert group consider to be the top five ethical lessons from the initial experience with COVID-19 that must be learned.

7.
Rev. bioét. (Impr.) ; 29(1): 21-26, enero-mar. 2021.
Artigo em Inglês | LILACS | ID: biblio-1251077

RESUMO

Abstract The purpose of this reflection is to include ethical principles in the discussion on resource allocation in times of covid-19. This study presents recent news and documents on the use of resources in the pandemic and principles such as justice, autonomy and beneficence. The comprehension that all human beings are worthy of respect, solidarity and protection can help pave the way for accelerating pandemic control for all.


Resumen El propósito de esta reflexión es incluir principios éticos en la discusión sobre la asignación de recursos en tiempos de covid-19. Se trata de un estudio que presenta noticias y documentos recientes sobre el uso de recursos en la pandemia y sobre principios como justicia, autonomía y beneficencia. La comprensión de que todos los seres humanos son dignos de respeto, solidaridad y protección puede ayudar a allanar el camino para acelerar el control de la pandemia para todos.


Resumo O objetivo desta reflexão é incluir princípios éticos na discussão sobre alocação de recursos em tempos de covid-19. Este estudo apresenta notícias e documentos recentes sobre uso de recursos na pandemia, e princípios como justiça, autonomia e beneficência. A compreensão de que todos os seres humanos merecem respeito, solidariedade e proteção pode ajudar a trilhar caminhos que acelerem o controle da pandemia para todos.


Assuntos
Justiça Social , Bioética , Pandemias , COVID-19
8.
Bull World Health Organ ; 99(2): 155-161, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33551509

RESUMO

Restrictive measures imposed because of the coronavirus disease 2019 (COVID-19) pandemic have resulted in severe social, economic and health effects. Some countries have considered the use of immunity certification as a strategy to relax these measures for people who have recovered from the infection by issuing these individuals a document, commonly called an immunity passport. This document certifies them as having protective immunity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the virus that causes COVID-19. The World Health Organization has advised against the implementation of immunity certification at present because of uncertainty about whether long-term immunity truly exists for those who have recovered from COVID-19 and concerns over the reliability of the proposed serological test method for determining immunity. Immunity certification can only be considered if scientific thresholds for assuring immunity are met, whether based on antibodies or other criteria. However, even if immunity certification became well supported by science, it has many ethical issues in terms of different restrictions on individual liberties and its implementation process. We examine the main considerations for the ethical acceptability of immunity certification to exempt individuals from restrictive measures during the COVID-19 pandemic. As well as needing to meet robust scientific criteria, the ethical acceptability of immunity certification depends on its uses and policy objectives and the measures in place to reduce potential harms, and prevent disproportionate burdens on non-certified individuals and violation of individual liberties and rights.


Les restrictions imposées dans le cadre de la lutte contre la pandémie de maladie à coronavirus 2019 (COVID-19) ont eu de lourdes conséquences économiques, sociales et sanitaires. Certains pays ont envisagé la mise en place d'une stratégie visant à alléger ces restrictions pour les individus guéris en leur octroyant un document communément appelé «passeport d'immunité¼. Ce document atteste qu'ils ont développé une immunité protectrice contre le coronavirus 2 du syndrome respiratoire aigu sévère (SARS-CoV-2), le virus à l'origine de la COVID-19. L'Organisation mondiale de la Santé a déconseillé l'usage du certificat d'immunité pour l'instant, car l'incertitude demeure quant à l'existence réelle d'une immunité à long terme pour ceux qui se sont remis de la COVID-19. En outre, la fiabilité des tests sérologiques censés déterminer si l'individu est immunisé n'est pas avérée. Un tel certificat ne peut être instauré que si les seuils scientifiques en matière d'immunité sont respectés, qu'ils soient fondés sur les anticorps ou sur d'autres critères. Néanmoins, même si le certificat d'immunité est désormais bien accepté par la science, il s'accompagne de nombreuses questions d'ordre éthique en ce qui concerne la limitation des libertés individuelles et la mise en œuvre. Dans le présent document, nous examinons les principales considérations à prendre en compte pour garantir l'acceptabilité éthique du certificat d'immunité visant à lever les mesures de restriction pour certaines personnes durant la pandémie de COVID-19. Cette acceptabilité éthique dépend non seulement de son degré de conformité à des critères scientifiques stricts, mais aussi de son usage, des objectifs politiques ainsi que des mesures mises en place pour atténuer les préjudices potentiels et éviter d'imposer une charge disproportionnée sur les individus dépourvus de certificat, ou de bafouer les droits et libertés de tout un chacun.


Las medidas restrictivas impuestas a causa de la pandemia de la enfermedad coronavirus de 2019 (COVID-19) han tenido graves efectos sociales, económicos y sanitarios. Algunos países han considerado la posibilidad de utilizar la certificación de inmunidad como estrategia para flexibilizar dichas medidas para las personas que se han recuperado de la infección mediante la expedición a dichas personas de un documento, comúnmente denominado pasaporte de inmunidad. Este documento certifica que han desarrollado inmunidad protectora contra el coronavirus-2 del síndrome respiratorio agudo severo (SARS-CoV-2), el virus que causa la COVID-19. La Organización Mundial de la Salud ha desaconsejado la aplicación de la certificación de la inmunidad en la actualidad debido a la incertidumbre sobre si existe realmente una inmunidad a largo plazo para quienes se han recuperado de la COVID-19 y a las preocupaciones sobre la fiabilidad del método de prueba serológica propuesto para determinar la inmunidad. La certificación de la inmunidad solo puede considerarse si se cumplen los umbrales científicos para asegurar la inmunidad, ya sea que se basen en anticuerpos o en otros criterios. Sin embargo, incluso si la certificación de la inmunidad llegara a estar bien respaldada por la ciencia, tiene muchas cuestiones éticas en cuanto a las diferentes restricciones de las libertades individuales y su proceso de aplicación. Examinamos las principales consideraciones sobre la aceptabilidad ética de la certificación de la inmunidad para eximir a los individuos de las medidas restrictivas durante la pandemia de la COVID-19. Además de necesitar cumplir criterios científicos sólidos, la aceptabilidad ética de la certificación de inmunidad depende de sus usos y objetivos de política y de las medidas que se apliquen para reducir los posibles daños y evitar que se impongan cargas desproporcionadas a las personas que no cuenten con dicha certificación y se violen las libertades y derechos individuales.


Assuntos
Teste Sorológico para COVID-19/ética , COVID-19/diagnóstico , Certificação/ética , Pandemias , Saúde Pública/ética , Humanos , Imunidade Humoral
9.
PLoS One ; 16(2): e0246540, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33571237

RESUMO

INTRODUCTION: Active pharmacovigilance studies are pivotal to better characterize vaccine safety. METHODS: These 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). RESULTS: A 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. CONCLUSION: The 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.


Assuntos
Vacinas contra Influenza/efeitos adversos , Farmacovigilância , Idoso , Brasil , Criança , Pré-Escolar , Feminino , Pessoal de Saúde/estatística & dados numéricos , Humanos , Lactente , Masculino , Gestantes
10.
AIDS Care ; 33(2): 253-261, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32567983

RESUMO

In Brazil prevention of mother to child HIV transmission guidelines recommend formula feeding. This qualitative study, carried out in a public clinic (CEADIPE/UNIFESP), aimed at exploring experiences of breastfeeding avoidance of women living with HIV living in São Paulo. Individual interviews were carried out with the support of a semi-structured questionnaire. Data was analyzed in a thematic approach with the support of AtlasTi®. During the months of January-February 2010, 25 women were interviewed, including women with (n = 12) and without previous breastfeeding experience (n = 13). Major themes identified were: Non-breastfeeding as a trigger for stigmatization, Non-breastfeeding, guilt and coping, Attitudes around non-breastfeeding for women with and without previous breastfeeding experience, and Women's support through non-breastfeeding. In conclusion women interviewed faced challenges related to HIV diagnosis, which got entangled with difficulties with breastfeeding avoidance. Different patterns of reaction and coping could be identified, regardless of mothers' previous breastfeeding experiences. Health systems were key in providing women living with HIV with tailored services and the necessary support.


Assuntos
Alimentação com Mamadeira/psicologia , Aleitamento Materno/psicologia , Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Mães/psicologia , Complicações Infecciosas na Gravidez/prevenção & controle , Brasil , Criança , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Lactente , Entrevistas como Assunto , Leite Humano/virologia , Gravidez , Pesquisa Qualitativa
11.
PloS One, v. 16, n. 2, e0246540, fev. 2021
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-3536

RESUMO

Active pharmacovigilance studies are pivotal to better characterize vaccine safety. Methods: These 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). Results: A 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. Conclusion: The 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.

12.
J Bioeth Inq ; 17(4): 627-631, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33169249

RESUMO

COVID-19 was recognized as a pandemic on March 11, 2020. Nine days later in Brazil, community transmission was deemed ongoing, and following what was already being put in place in various affected countries, restrictive and physical distancing measures that varied in severity across the different states were adopted. Adherence to restrictive and physical distancing measures depends on the general acceptance of public health measures as well as communities' financial leverage. This article aims to explore and discuss ethical facilitators and barriers to the implementation of physical distancing measures within three dimensions: political, socio-economic, and scientific. Furthermore, we would like to discuss ways to ethically promote restrictive and physical distancing measures in a large and unequal country like Brazil. There is an urgent need for transparent, consistent, and inclusive communication with the public, respecting the most vulnerable populations and attempting to minimize the disproportionate burden on them.


Assuntos
Temas Bioéticos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Controle de Doenças Transmissíveis/organização & administração , Brasil/epidemiologia , Humanos , Pandemias , Distanciamento Físico , Saúde Pública/ética , Quarentena/ética , SARS-CoV-2
15.
Rev Saude Publica ; 54: 50, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32491091

RESUMO

OBJECTIVE To estimate the proportion and total number of the general adult population who may be at higher risk of severe Covid-19 in Brazil. METHODS We included 51,770 participants from a nationally representative, household-based health survey (PNS) conducted in Brazil. We estimated the proportion and number of adults (≥ 18 years) at risk of severe Covid-19 by sex, educational level, race/ethnicity, and state based on the presence of one or more of the following risk factors: age ≥ 65 years or medical diagnosis of cardiovascular disease, diabetes, hypertension, chronic respiratory disease, cancer, stroke, chronic kidney disease and moderate to severe asthma, smoking status, and obesity. RESULTS Adults at risk of severe Covid-19 in Brazil varied from 34.0% (53 million) to 54.5% (86 million) nationwide. Less-educated adults present a 2-fold higher prevalence of risk factors compared to university graduated. We found no differences by sex and race/ethnicity. São Paulo, Rio de Janeiro, Minas Gerais, and Rio Grande do Sul were the most vulnerable states in absolute and relative terms of adults at risk. CONCLUSIONS Proportion and total number of adults at risk of severe Covid-19 are high in Brazil, with wide variation across states and adult subgroups. These findings should be considered while designing and implementing prevention measures in Brazil. We argue that these results support broad social isolation measures, particularly when testing capacity for SARS-CoV-2 is limited.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/etiologia , Pneumonia Viral/epidemiologia , Pneumonia Viral/etiologia , Medição de Risco , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , COVID-19 , Doença Crônica , Escolaridade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Prevalência , Fatores de Risco , SARS-CoV-2 , Índice de Gravidade de Doença , Fatores Sexuais , Fatores Socioeconômicos , Adulto Jovem
18.
Lancet Infect Dis ; 20(7): 839-850, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32220283

RESUMO

BACKGROUND: The Butantan Institute has manufactured a lyophilised tetravalent live-attenuated dengue vaccine Butantan-DV, which is analogous to the US National Institutes of Health (NIH) TV003 admixture. We aimed to assess the safety and immunogenicity of Butantan-DV. METHODS: We did a two-step, double-blind, randomised placebo-controlled phase 2 trial at two clinical sites in São Paulo, Brazil. We recruited healthy volunteers aged 18-59 years; pregnant women, individuals with a history of neurological, heart, lung, liver or kidney disease, diabetes, cancer, or autoimmune diseases, and individuals with HIV or hepatitis C were excluded. Step A was designed as a small bridge-study between Butantan-DV and TV003 in DENV-naive participants. In step A, we planned to randomly assign 50 dengue virus (DENV)-naive individuals to receive two doses of Butantan-DV, TV003, or placebo, given 6 months apart. In step B, we planned to randomly assign 250 participants (DENV-naive and DENV-exposed) to receive one dose of Butantan-DV or placebo. Participants were randomly assigned, by computer-generated block randomisation (block sizes of five); participants in step A were randomly assigned (2:2:1) to receive Butantan-DV, TV003, or placebo and participants in step B were randomly assigned (4:1) to receive Butantan-DV or placebo. Participants and study staff were unaware of treatment allocation. The primary safety outcome was the frequency of solicited and unsolicited local and systemic adverse reactions within 21 days of the first vaccination, analysed by intention to treat. The primary immunogenicity outcome was seroconversion rates of the DENV-1-4 serotypes measured 91 days after the first vaccination, analysed in the per-protocol population, which included all participants in step A, and all participants included in step B who completed all study visits with serology sample collection. This trial is registered with ClinicalTrials.gov, NCT01696422. FINDINGS: Between Nov 5, 2013, and Sept 21, 2015, 300 individuals were enrolled and randomly assigned: 155 (52%) DENV-naive participants and 145 (48%) DENV-exposed participants. Of the 155 DENV-naive participants, 97 (63%) received Butantan-DV, 17 (11%) received TV003, and 41 (27%) received placebo. Of the 145 DENV-exposed participants, 113 (78%) received Butantan-DV, three (2%) received TV003, and 29 (20%) received placebo. Butantan-DV and TV003 were both immunogenic, well-tolerated, and no serious adverse reactions were observed. In step A, rash was the most frequent adverse event (16 [845] of 19 participants in the Butantan-DV group and 13 [76%] of 17 participants in the TV003 group). Viraemia was similar between the Butantan-DV and TV003 groups. Of the 85 DENV-naive participants in the Butantan-DV group who attended all visits for sample collection for seroconversion analysis and thus were included in the per-protocol analysis population, 74 (87%) achieved seroconversion to DENV-1, 78 (92%) to DENV-2, 65 (76%) to DENV-3, and 76 (89%) to DENV-4. Of the 101 DENV-exposed participants in the Butantan-DV group who attended all visits for sample collection for seroconversion analysis, 82 (81%) achieved seroconversion to DENV-1, 79 (78%) to DENV-2, 83 (82%) to DENV-3, and 78 (77%) to DENV-4. INTERPRETATION: Butantan-DV and TV003 were safe and induced robust, balanced neutralising antibody responses against the four DENV serotypes. Efficacy evaluation of the Butantan-DV vaccine is ongoing. FUNDING: Intramural Research Program US NIH National Institute of Allergy and Infectious Diseases, Brazilian National Bank for Economic and Social Development, Fundação de Amparo à Pesquisa do Estado de São Paulo, and Fundação Butantan.


Assuntos
Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Imunogenicidade da Vacina , Vacinas Atenuadas/imunologia , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Brasil , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Soroconversão , Vacinação , Adulto Jovem
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