RESUMO
BACKGROUND: Butantan-Dengue Vaccine (Butantan-DV) is an investigational, single-dose, live, attenuated, tetravalent vaccine against dengue disease, but data on its overall efficacy are needed. METHODS: In an ongoing phase 3, double-blind trial in Brazil, we randomly assigned participants to receive Butantan-DV or placebo, with stratification according to age (2 to 6 years, 7 to 17 years, and 18 to 59 years); 5 years of follow-up is planned. The objectives of the trial were to evaluate overall vaccine efficacy against symptomatic, virologically confirmed dengue of any serotype occurring more than 28 days after vaccination (the primary efficacy end point), regardless of serostatus at baseline, and to describe safety up to day 21 (the primary safety end point). Here, vaccine efficacy was assessed on the basis of 2 years of follow-up for each participant, and safety as solicited vaccine-related adverse events reported up to day 21 after injection. Key secondary objectives were to assess vaccine efficacy among participants according to dengue serostatus at baseline and according to the dengue viral serotype; efficacy according to age was also assessed. RESULTS: Over a 3-year enrollment period, 16,235 participants received either Butantan-DV (10,259 participants) or placebo (5976 participants). The overall 2-year vaccine efficacy was 79.6% (95% confidence interval [CI], 70.0 to 86.3) - 73.6% (95% CI, 57.6 to 83.7) among participants with no evidence of previous dengue exposure and 89.2% (95% CI, 77.6 to 95.6) among those with a history of exposure. Vaccine efficacy was 80.1% (95% CI, 66.0 to 88.4) among participants 2 to 6 years of age, 77.8% (95% CI, 55.6 to 89.6) among those 7 to 17 years of age, and 90.0% (95% CI, 68.2 to 97.5) among those 18 to 59 years of age. Efficacy against DENV-1 was 89.5% (95% CI, 78.7 to 95.0) and against DENV-2 was 69.6% (95% CI, 50.8 to 81.5). DENV-3 and DENV-4 were not detected during the follow-up period. Solicited systemic vaccine- or placebo-related adverse events within 21 days after injection were more common with Butantan-DV than with placebo (58.3% of participants, vs. 45.6%). CONCLUSIONS: A single dose of Butantan-DV prevented symptomatic DENV-1 and DENV-2, regardless of dengue serostatus at baseline, through 2 years of follow-up. (Funded by Instituto Butantan and others; DEN-03-IB ClinicalTrials.gov number, NCT02406729, and WHO ICTRP number, U1111-1168-8679.).
Assuntos
Vacinas contra Dengue , Vírus da Dengue , Dengue , Vacinas Atenuadas , Adulto , Criança , Pré-Escolar , Humanos , Anticorpos Antivirais , Dengue/prevenção & controle , Vacinas contra Dengue/efeitos adversos , Vacinas contra Dengue/uso terapêutico , Vírus da Dengue/imunologia , Método Duplo-Cego , Vacinação , Vacinas , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/uso terapêutico , Brasil , Eficácia de Vacinas , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , SeguimentosRESUMO
BACKGROUND Butantan–Dengue Vaccine (Butantan-DV) is an investigational, single-dose, live, attenuated, tetravalent vaccine against dengue disease, but data on its overall efficacy are needed. METHODS In an ongoing phase 3, double-blind trial in Brazil, we randomly assigned participants to receive Butantan-DV or placebo, with stratification according to age (2 to 6 years, 7 to 17 years, and 18 to 59 years); 5 years of follow-up is planned. The objectives of the trial were to evaluate overall vaccine efficacy against symptomatic, virologically con firmed dengue of any serotype occurring more than 28 days after vaccination (the primary efficacy end point), regardless of serostatus at baseline, and to describe safety up to day 21 (the primary safety end point). Here, vaccine efficacy was assessed on the basis of 2 years of follow-up for each participant, and safety as solicited vaccine-related adverse events reported up to day 21 after injection. Key secondary objectives were to assess vaccine efficacy among participants according to dengue serostatus at baseline and according to the dengue viral serotype; efficacy according to age was also assessed. RESULTS Over a 3-year enrollment period, 16,235 participants received either Butantan-DV (10,259 participants) or placebo (5976 participants). The overall 2-year vaccine effi cacy was 79.6% (95% confidence interval [CI], 70.0 to 86.3) — 73.6% (95% CI, 57.6 to 83.7) among participants with no evidence of previous dengue exposure and 89.2% (95% CI, 77.6 to 95.6) among those with a history of exposure. Vaccine effi cacy was 80.1% (95% CI, 66.0 to 88.4) among participants 2 to 6 years of age, 77.8% (95% CI, 55.6 to 89.6) among those 7 to 17 years of age, and 90.0% (95% CI, 68.2 to 97.5) among those 18 to 59 years of age. Efficacy against DENV-1 was 89.5% (95% CI, 78.7 to 95.0) and against DENV-2 was 69.6% (95% CI, 50.8 to 81.5). DENV-3 and DENV-4 were not detected during the follow-up period. Solicited systemic vaccine- or placebo-related adverse events within 21 days after injection were more common with Butantan-DV than with placebo (58.3% of participants, vs. 45.6%). CONCLUSIONS A single dose of Butantan-DV prevented symptomatic DENV-1 and DENV-2, regard less of dengue serostatus at baseline, through 2 years of follow-up. (Funded by Instituto Butantan and others; DEN-03-IB ClinicalTrials.gov number, NCT02406729, and WHO ICTRP number, U1111-1168-8679.)
RESUMO
Objective: To describe the successful implementation of an enhanced public health surveillance system based on early detection, tracing contacts, and patient follow-up and support. Study design: A prospective observational cohort study conducted in Serrana, São Paulo State, Brazil. Methods: The implementation was based on four axes: increasing the access to SARS-CoV-2 testing; correct swab collection; testing patients with mild symptoms; and patient follow-up. Positivity rate, patient demographic and clinical characteristics, dynamics of disease severity, SARS-CoV-2 genome evolution, and the impact on COVID-19 research were assessed from August 23, 2020 to February 6, 2021 (between epidemiological week 35/2020 and 5/2021, a total of 24 weeks). Results: The number of sites collecting rt-PCR for SARS-CoV-2 was increased from one to seven points and staff was trained in the correct use of personal protective equipment and in the swab collection technique. During the study period, 6728 samples were collected from 6155 participants vs. 2770 collections in a similar period before. SARS-CoV-2 RNA was detected in 1758 (26.1%) swabs vs. 1117 (36.7%) before the implementation of the surveillance system (p < 0.001). Positivity rates varied widely between epidemiological weeks 35/2020 and 5/2021 (IQR, 12.8%-31.3%). Out of COVID-19 patients, 91.1% were adults at a median age of 35 years (IQR, 25-50 years), 42.6% were men and 57.4% were women, with a SARS-CoV-2 positivity rate of 28.6% and 24.4% (p < 0.001), respectively. The most common symptoms were headache (72.6%), myalgia (65.0%), and cough (61.7%). Comorbidities were found in 20.8% of patients, the most common being hypertension and diabetes. According to the World Health Organization clinical progression scale, 93.5% of patients had mild disease, 1.6% were hospitalized with moderate disease, 3.2% were hospitalized with severe disease, and 1.4% died. The enhanced surveillance system led to the development of COVID-19 related research. Conclusions: The enhanced surveillance system in Serrana improved COVID-19 understanding and management. By integrating community and academic institutions, it was possible to monitor SARS-CoV-2 positive cases and variants, follow the epidemic trend, guide patients, and develop relevant research projects.
RESUMO
An effective vaccine against the dengue virus (DENV) should induce a balanced, long-lasting antibody (Ab) response against all four viral serotypes. The burst of plasmablasts in the peripheral blood after vaccination may reflect enriched vaccine-specific Ab secreting cells. Here we characterize the acute plasmablast responses from naïve and DENV-exposed individuals following immunization with the live attenuated tetravalent (LAT) Butantan DENV vaccine (Butantan-DV). The frequency of circulating plasmablasts was determined by flow cytometric analysis of fresh whole blood specimens collected from 40 participants enrolled in the Phase II Butantan-DV clinical trial (NCT01696422) before and after (days 6, 12, 15 and 22) vaccination. We observed a peak in the number of circulating plasmablast at day 15 after vaccination in both the DENV naïve and the DENV-exposed vaccinees. DENV-exposed vaccinees experienced a significantly higher plasmablast expansion. In the DENV-naïve vaccinees, plasmablasts persisted for approximately three weeks longer than among DENV-exposed volunteers. Our findings indicate that the Butantan-DV can induce plasmablast responses in both DENV-naïve and DENV-exposed individuals and demonstrate the influence of pre-existing DENV immunity on Butantan DV-induced B-cell responses.
Assuntos
Vacinas contra Dengue , Vírus da Dengue , Anticorpos Antivirais , Brasil , Humanos , Vacinas AtenuadasRESUMO
BACKGROUND: Immunogenicity of influenza vaccine in transplant recipients is suboptimal and alternative vaccination regimens are necessary. METHODS: We compared the immunogenicity of a standard-dose trivalent inactivated influenza vaccination (SDTIIV), double-dose trivalent inactivated influenza vaccination (DDTIIV), and booster-dose trivalent inactivated influenza vaccination (BDTIIV) of the 2014 seasonal trivalent inactivated influenza vaccine in kidney transplant recipients. We randomized 176 participants to SDTIIV (59), DDTIIV (59), and BDTIIV regimens (58). Antibody titers were determined by hemagglutination inhibition at enrollment and 21 d postvaccination. Seroprotection rates (SPRs), seroconversion rates (SCRs), and geometric mean ratios (GMRs) were analyzed separately for participants with low (<1:40) and high (≥1:40) prevaccination antibody titers. RESULTS: Vaccination was confirmed for 172 participants. Immunogenicity analysis was done for 149 participants who provided postvaccination blood samples. In the subgroup with high prevaccination antibody titers, all vaccination regimens induced SPR > 70% to all antigens, but SCR and GMR were below the recommendations. In the subgroup with low prevaccination antibody titers, DDTIIV and BDTIIV regimens induced adequate SCR > 40% and GMR > 2.5 for all antigens, whereas SDTIIV achieved the same outcomes only for influenza B. SPRs were >70% only after DDTIIV (A/H1N1-77.8%) and BDTIIV (A/H3N2-77.8%). BDTIIV regimen independently increased seroprotection to A/H1N1 (PR = 2.58; P = 0.021) and A/H3N2 (PR = 2.21; P = 0.004), whereas DDTIIV independently increased seroprotection to A/H1N1 (PR = 2.59; P = 0.021). CONCLUSIONS: Our results suggest that DDTIIV and BDTIIV regimens are more immunogenic than SDTIIV, indicating the need for head-to-head multicenter clinical trials to further evaluate their efficacy.
Assuntos
Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Transplante de Rim , Anticorpos Antivirais , Testes de Inibição da Hemaglutinação , Humanos , Vírus da Influenza A Subtipo H3N2 , Vacinas contra Influenza/efeitos adversos , Influenza Humana/prevenção & controle , Transplante de Rim/efeitos adversos , Projetos Piloto , Estações do Ano , Transplantados , Vacinas de Produtos InativadosRESUMO
Objective To describe the successful implementation of an enhanced public health surveillance system based on early detection, tracing contacts, and patient follow-up and support. Study design A prospective observational cohort study conducted in Serrana, São Paulo State, Brazil. Methods The implementation was based on four axes: increasing the access to SARS-CoV-2 testing; correct swab collection; testing patients with mild symptoms; and patient follow-up. Positivity rate, patient demographic and clinical characteristics, dynamics of disease severity, SARS-CoV-2 genome evolution, and the impact on COVID-19 research were assessed from August 23, 2020 to February 6, 2021 (between epidemiological week 35/2020 and 5/2021, a total of 24 weeks). Results The number of sites collecting rt-PCR for SARS-CoV-2 was increased from one to seven points and staff was trained in the correct use of personal protective equipment and in the swab collection technique. During the study period, 6728 samples were collected from 6155 participants vs. 2770 collections in a similar period before. SARS-CoV-2 RNA was detected in 1758 (26.1%) swabs vs. 1117 (36.7%) before the implementation of the surveillance system (p < 0.001). Positivity rates varied widely between epidemiological weeks 35/2020 and 5/2021 (IQR, 12.8%–31.3%). Out of COVID-19 patients, 91.1% were adults at a median age of 35 years (IQR, 25–50 years), 42.6% were men and 57.4% were women, with a SARS-CoV-2 positivity rate of 28.6% and 24.4% (p < 0.001), respectively. The most common symptoms were headache (72.6%), myalgia (65.0%), and cough (61.7%). Comorbidities were found in 20.8% of patients, the most common being hypertension and diabetes. According to the World Health Organization clinical progression scale, 93.5% of patients had mild disease, 1.6% were hospitalized with moderate disease, 3.2% were hospitalized with severe disease, and 1.4% died. The enhanced surveillance system led to the development of COVID-19 related research. Conclusions The enhanced surveillance system in Serrana improved COVID-19 understanding and management. By integrating community and academic institutions, it was possible to monitor SARS-CoV-2 positive cases and variants, follow the epidemic trend, guide patients, and develop relevant research projects.
RESUMO
An effective vaccine against the dengue virus (DENV) should induce a balanced, long-lasting antibody (Ab) response against all four viral serotypes. The burst of plasmablasts in the peripheral blood after vaccination may reflect enriched vaccine-specific Ab secreting cells. Here we characterize the acute plasmablast responses from naïve and DENV-exposed individuals following immunization with the live attenuated tetravalent (LAT) Butantan DENV vaccine (Butantan-DV). The frequency of circulating plasmablasts was determined by flow cytometric analysis of fresh whole blood specimens collected from 40 participants enrolled in the Phase II Butantan-DV clinical trial (NCT01696422) before and after (days 6, 12, 15 and 22) vaccination. We observed a peak in the number of circulating plasmablast at day 15 after vaccination in both the DENV naïve and the DENV-exposed vaccinees. DENV-exposed vaccinees experienced a significantly higher plasmablast expansion. In the DENV-naïve vaccinees, plasmablasts persisted for approximately three weeks longer than among DENV-exposed volunteers. Our findings indicate that the Butantan-DV can induce plasmablast responses in both DENV-naïve and DENV-exposed individuals and demonstrate the influence of pre-existing DENV immunity on Butantan DV-induced B-cell responses.
RESUMO
Background: Immunogenicity of influenza vaccine in transplant recipients is suboptimal and alternative vaccination regimens are necessary. Methods: We compared the immunogenicity of a standard-dose trivalent inactivated influenza vaccination (SDTIIV), double-dose trivalent inactivated influenza vaccination (DDTIIV) and booster-dose trivalent inactivated influenza vaccination (BDTIIV) of the 2014 seasonal trivalent inactivated influenza vaccine in kidney transplant recipients. We randomized 176 participants to SDTIIV (59), DDTIIV (59) and BDTIIV regimens (58). Antibody titres were determined by hemagglutination inhibition at enrollment and 21 days post-vaccination. Seroprotection rates (SPR), seroconversion rates (SCR) and geometric mean ratios (GMR) were analyzed separately for participants with low (<1:40) and high (≥1:40) pre-vaccination antibody titres. Results: Vaccination was confirmed for 172 participants. Immunogenicity analysis was done for 149 participants who provided post-vaccination blood samples. In the subgroup with high pre-vaccination antibody titres, all vaccination regimens induced SPR >70% to all antigens, but SCR and GMR were below the recommendations. In the subgroup with low pre-vaccination antibody titres, DDTIIV and BDTIIV regimens induced adequate SCR >40% and GMR >2,5 for all antigens, while SDTIIV achieved the same outcomes only for influenza B. SPR were >70% only after DDTIIV (A/H1N1 - 77.8%) and BDTIIV (A/H3N2 - 77.8%). BDTIIV regimen independently increased seroprotection to A/H1N1 (PR=2.58; p=0.021) and A/H3N2 (PR=2.21; p=0.004), while DDTIIV independently increased seroprotection to A/H1N1 (PR=2.59; p=0.021). Conclusion: Our results suggest that DDTIIV and BDTIIV regimens are more immunogenic than SDTIIV, indicating the need for head-to-head multicenter clinical trials to further evaluate their efficacy.
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This chapter describes the eruption and spread of the SARS-COV-2 virus throughout Brazil. We also describe the governmental measures used to combat the virus, the regional influences impacting viral spreading, and the prevalence of the disease in different Brazilian subpopulations. It is hoped that such information will contribute to the control of the virus and help to prepare the region for future pandemics.
Assuntos
COVID-19 , Pandemias , Brasil/epidemiologia , Humanos , Prevalência , SARS-CoV-2RESUMO
OBJECTIVES: To evaluate the efficacy of two doses of the adsorbed vaccine COVID-19 (inactivated) produced by Sinovac in symptomatic individuals, with virological confirmation of COVID-19, two weeks after the completion of the two-dose vaccination regimen, aged 18 years or older who work as health professionals providing care to patients with possible or confirmed COVID-19. To describe the occurrence of adverse reactions associated with the administration of each of two doses of the adsorbed vaccine COVID-19 (inactivated) produced by Sinovac up to one week after vaccination in Adults (18-59 years of age) and Elderly (60 years of age or more). TRIAL DESIGN: This is a Phase III, randomized, multicenter, endpoint driven, double-blind, placebo-controlled clinical trial to assess the efficacy and safety of the adsorbed vaccine COVID-19 (inactivated) produced by Sinovac. The adsorbed vaccine COVID-19 (inactivated) produced by Sinovac (product under investigation) will be compared to placebo. Voluntary participants will be randomized to receive two intramuscular doses of the investigational product or the placebo, in a 1: 1 ratio, stratified by age group (18 to 59 years and 60 years or more) and will be monitored for one year by active surveillance of COVID-19. Two databases will be established according to the age groups: one for adults (18-59 years) and one for the elderly (60 years of age or older). The threshold to consider the vaccine efficacious will be to reach a protection level of at least 50%, as proposed by the World Health Organization and the FDA. Success in this criterion will be defined by sequential monitoring with adjustment of the lower limit of the 95% confidence interval above 30% for the primary efficacy endpoint. PARTICIPANTS: Healthy participants and / or participants with clinically controlled disease, of both genders, 18 years of age or older, working as health professionals performing care in units specialized in direct contact with people with possible or confirmed cases of COVID-19. Participation of pregnant women and those who are breastfeeding, as well as those intending to become pregnant within three months after vaccination will not be allowed. Participants will only be included after signing the voluntary Informed Consent Form and ensuring they undergo screening evaluation and conform to all the inclusion and exclusion criteria. All the clinical sites are located in Brazil. INTERVENTION AND COMPARATOR: Experimental intervention: The vaccine was manufactured by Sinovac Life Sciences (Beijing, China) and contains 3 µg/0.5 mL (equivalent to 600 SU per dose) of inactivated SARS-CoV-2 virus, and aluminium hydroxide as adjuvant. Control comparator: The placebo contains aluminium hydroxide in a 0.5 mL solution The schedule of both, experimental intervention and placebo is two 0.5 mL doses IM (deltoid) with a two week interval. MAIN OUTCOMES: The primary efficacy endpoint is the incidence of symptomatic cases of virologically confirmed COVID-19 two weeks after the second vaccination. The virological diagnosis will be confirmed by detection of SARS-CoV-2 nucleic acid in a clinical sample. The primary safety endpoint is the frequency of solicited and unsolicited local and systemic adverse reactions during the period of one week after vaccination according to age group in adult (18-59 years old) and elder (60 years of age or older) subjects. Adverse reactions are defined as adverse events that have a reasonable causal relationship to vaccination. RANDOMISATION: There will be two randomization lists, one for each age group, based on the investigational products to be administered, i.e., vaccine or placebo at a 1: 1 ratio. Each randomization list will be made to include up to 11,800 (18-59 year-old) adults, and 1,260 elderly (60 y-o and older) participants, the maximum number of participants needed per age group. An electronic central randomization system will be used to designate the investigational product that each participant must receive. BLINDING (MASKING): This trial is designed as a double-blind study to avoid introducing bias in the evaluation of efficacy, safety and immunogenicity. The clinical care team, the professionals responsible for the vaccination and the participants will not know which investigational product will be administered. Only pharmacists or nurses in the study who are responsible for the randomization, separation and blinding of the investigational product will have access to unblinded information. The sponsor's operational team will also remain blind. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): The total number of participants needed to evaluate efficacy, 13,060 participants, satisfies the needed sample size calculated to evaluate safety. Therefore, the total number obtained for efficacy will be the number retained for the study. Up to 13,060 participants are expected to enter the study, with up to 11,800 participants aged 18 to 59 years and 1,260 elderly participants aged 60 and over. Half of the participants of each group will receive the experimental vaccine and half of them will receive the placebo. The recruitment of participants may be modified as recommended by the Data Safety Monitoring Committee at time of the interim unblinded analysis or blind assessment of the COVID-19 attack rate during the study. TRIAL STATUS: Protocol version 2.0 - 24-Aug-2020. Recruitment started on July 21st, 2020. The recruitment is expected to conclude in October 2020. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT0445659 . Registry on 2 July 2020 FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.
Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinação/métodos , Vacinas/uso terapêutico , Adolescente , Adulto , Idoso , Betacoronavirus/imunologia , Brasil/epidemiologia , COVID-19 , Estudos de Casos e Controles , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Gerenciamento de Dados , Método Duplo-Cego , Feminino , Pessoal de Saúde/estatística & dados numéricos , Humanos , Incidência , Consentimento Livre e Esclarecido/ética , Injeções Intramusculares , Masculino , Pessoa de Meia-Idade , Placebos/administração & dosagem , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , SARS-CoV-2 , Segurança , Terapias em Estudo/métodos , Resultado do Tratamento , Vacinas/administração & dosagem , Vacinas/efeitos adversos , Adulto JovemRESUMO
Before a vaccine against SARS-CoV-2 became available, several measures to control COVID-19 pandemic are necessary. Analogously, in the absence of an available vaccine, Combination HIV Prevention Programmes have consolidated a large experience of biomedical, behavioral and structural interventions suitable for several epidemiological settings. Adaptation of such experiences can organize mid-term and long-term responses to face COVID-19.
Antes de que se disponga de una vacuna contra el SARS-CoV-2, son necesarias varias medidas para controlar la pandemia de COVID-19. En forma análoga, en ausencia de una vacuna disponible, los Programas de Prevención del VIH combinados han consolidado una gran experiencia de intervenciones biomédicas, conductuales y estructurales adecuadas para varios entornos epidemiológicos. La adaptación de estas experiencias puede organizar respuestas a mediano y largo plazo para hacer frente a la epidemia de COVID-19.
Assuntos
Infecções por Coronavirus/prevenção & controle , Infecções por HIV/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , COVID-19 , Vacinas contra COVID-19 , Infecções por Coronavirus/epidemiologia , Infecções por HIV/epidemiologia , Humanos , Pneumonia Viral/epidemiologia , Vacinas Virais/administração & dosagemRESUMO
Abstract Before a vaccine against SARS-CoV-2 became available, several measures to control COVID-19 pandemic are necessary. Analogously, in the absence of an available vaccine, Combination HIV Prevention Programmes have consolidated a large experience of biomedical, behavioral and structural interventions suitable for several epidemiological settings. Adaptation of such experiences can organize mid-term and long-term responses to face COVID-19.
Resumen Antes de que se disponga de una vacuna contra el SARS-CoV-2, son necesarias varias medidas para controlar la pandemia de COVID-19. En forma análoga, en ausencia de una vacuna disponible, los Programas de Prevención del VIH combinados han consolidado una gran experiencia de intervenciones biomédicas, conductuales y estructurales adecuadas para varios entornos epidemiológicos. La adaptación de estas experiencias puede organizar respuestas a mediano y largo plazo para hacer frente a la epidemia de COVID-19.
Assuntos
Humanos , Pneumonia Viral/prevenção & controle , Infecções por HIV/prevenção & controle , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Vacinas Virais/administração & dosagem , Infecções por HIV/epidemiologia , Infecções por Coronavirus/epidemiologia , Vacinas contra COVID-19 , COVID-19RESUMO
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 JovemRESUMO
Before a vaccine against SARS-CoV-2 became available, several measures to control COVID-19 pandemic are necessary. Analogously, in the absence of an available vaccine, Combination HIV Prevention Programmes have consolidated a large experience of biomedical, behavioral and structural interventions suitable for several epidemiological settings. Adaptation of such experiences can organize mid-term and long-term responses to face COVID-19.
RESUMO
In controlled human infection studies (CHIs), participants are deliberately exposed to infectious agents in order to better understand the mechanism of infection or disease and test therapies or vaccines. While most CHIs have been conducted in high‐income countries, CHIs have recently been expanding into low‐ and middle‐income countries (LMICs). One potential ethical concern about this expansion is the challenge of obtaining the voluntary informed consent of participants, especially those who may not be literate or have limited education. In some CHIs in LMICs, researchers have attempted to address this potential concern by limiting access to literate or educated populations. In this paper, we argue that this practice is unjustified, as it does not increase the chances of obtaining valid informed consent and therefore unfairly excludes illiterate populations and populations with lower education. Instead, we recommend that investigators improve the informed consent process by drawing on existing data on obtaining informed consent in these populations and interventions aimed at improving their understanding. Based on a literature review, we provide concrete suggestions for how to follow this recommendation and ensure that populations with lower literacy or education are given a fair opportunity to protect their rights and interests in the informed consent process.
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Human challenge trials (HCTs) deliberately infect participants in order to test vaccines and treatments in a controlled setting, rather than enrolling individuals with natural exposure to a disease. HCTs are therefore potentially powerful tools to prepare for future outbreaks of emerging infectious diseases. Yet when an infectious disease is emerging, there is often substantial risk and uncertainty about its complications, and few available interventions, making an HCT ethically complex. In light of the need to consider ethical issues proactively as a part of epidemic preparedness, we use the case of a Zika virus HCT to explore whether and when HCTs might be ethically justified to combat emerging infectious diseases. We conclude that emerging infectious diseases could be appropriate candidates for HCTs and we identify relevant considerations and provide a case example to illustrate when they might be ethically acceptable.