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2.
Ann Intern Med ; 2020 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-33090877

RESUMO

Several vaccine candidates to protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (COVID-19) have entered or will soon enter large-scale, phase 3, placebo-controlled randomized clinical trials. To facilitate harmonized evaluation and comparison of the efficacy of these vaccines, a general set of clinical endpoints is proposed, along with considerations to guide the selection of the primary endpoints on the basis of clinical and statistical reasoning. The plausibility that vaccine protection against symptomatic COVID-19 could be accompanied by a shift toward more SARS-CoV-2 infections that are asymptomatic is highlighted, as well as the potential implications of such a shift.

3.
J Infect Dis ; 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33104218

RESUMO

BACKGROUND: Patients with HIV (PWH) can present with new or worsening symptoms associated with Mycobacterium avium complex (MAC) infection shortly after antiretroviral therapy (ART) initiation as MAC immune reconstitution inflammatory syndrome (MAC-IRIS). In this study, we assessed the utility of several laboratory tests as predictors of MAC-IRIS. METHODS: PWH with clinical and histologic and/or microbiologic evidence of MAC-IRIS were identified and followed up to 96 weeks post-ART initiation within a prospective study of 206 ART-naïve patients with CD4 <100 cells/µL. RESULTS: Fifteen (7.3%) patients presented with MAC-IRIS within a median interval of 26 days after ART initiation. Patients who developed MAC-IRIS had lower BMI, lower hemoglobin levels, a higher alkaline phosphatase and increased CD38 frequency and MFI on CD8 + T-cells, at the time of ART initiation compared to non-MAC IRIS patients. A decision tree inference model revealed that stratifying patients based on levels of alkaline phosphatase and D-dimer could predict the likelihood of MAC-IRIS. A binary logistic regression demonstrated that higher levels of alkaline phosphatase at baseline were associated with increased risk of MAC-IRIS development. CONCLUSIONS: High alkaline phosphatase levels and increased CD8 + T-cell activation with low CD4 counts at ART initiation should warrant suspicion for subsequent development of MAC-IRIS.

4.
Nat Commun ; 11(1): 3195, 2020 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-32581216

RESUMO

Penile acquisition of HIV accounts for most infections among men globally. Nevertheless, candidate HIV interventions for men advance to clinical trials without preclinical efficacy data, due primarily to a paucity of relevant animal models of penile HIV infection. Using our recently developed macaque model, we show that a single subcutaneous administration of broadly neutralizing antibody (bNAb) 10-1074 conferred durable protection against repeated penile exposures to simian-human immunodeficiency virus (SHIVSF162P3). Macaques co-administered bNAbs 10-1074 and 3BNC117, or 3BNC117 alone, also exhibited significant protection against repeated vaginal SHIVAD8-EO exposures. Regression modeling estimated that individual plasma bNAb concentrations of 5 µg ml-1 correlated with ≥99.9% relative reduction in SHIV infection probability via penile (10-1074) or vaginal (10-1074 or 3BNC117) challenge routes. These results demonstrate that comparably large reductions in penile and vaginal SHIV infection risk among macaques were achieved at clinically relevant plasma bNAb concentrations and inform dose selection for the development of bNAbs as long-acting pre-exposure prophylaxis candidates for use by men and women.


Assuntos
Vacinas contra a AIDS/administração & dosagem , Anticorpos Amplamente Neutralizantes/administração & dosagem , Anticorpos Anti-HIV/administração & dosagem , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Síndrome de Imunodeficiência Adquirida dos Símios/transmissão , Vírus da Imunodeficiência Símia/imunologia , Vacinas contra a AIDS/sangue , Animais , Anticorpos Amplamente Neutralizantes/sangue , Modelos Animais de Doenças , Feminino , Anticorpos Anti-HIV/sangue , Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Meia-Vida , Imunização Passiva , Macaca mulatta , Masculino , Pênis/imunologia , Pênis/virologia , Profilaxia Pré-Exposição , Vagina/imunologia , Vagina/virologia
5.
bioRxiv ; 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32577633

RESUMO

We remain largely without effective prophylactic/therapeutic interventions for COVID-19. Although many human clinical trials are ongoing, there remains a deficiency of supportive preclinical drug efficacy studies. Here we assessed the prophylactic/therapeutic efficacy of hydroxychloroquine (HCQ), a drug of interest for COVID-19 management, in two animal models. When used for prophylaxis or treatment neither the standard human malaria dose (6.5 mg/kg) nor a high dose (50 mg/kg) of HCQ had any beneficial effect on clinical disease or SARS-CoV-2 kinetics (replication/shedding) in the Syrian hamster disease model. Similarly, HCQ prophylaxis/treatment (6.5 mg/kg) did not significantly benefit clinical outcome nor reduce SARS-CoV-2 replication/shedding in the upper and lower respiratory tract in the rhesus macaque disease model. In conclusion, our preclinical animal studies do not support the use of HCQ in prophylaxis/treatment of COVID-19.

6.
bioRxiv ; 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32577634

RESUMO

A SARS-CoV-2 vaccine is needed to control the global COVID-19 public health crisis. Atomic-level structures directed the application of prefusion-stabilizing mutations that improved expression and immunogenicity of betacoronavirus spike proteins. Using this established immunogen design, the release of SARS-CoV-2 sequences triggered immediate rapid manufacturing of an mRNA vaccine expressing the prefusion-stabilized SARS-CoV-2 spike trimer (mRNA-1273). Here, we show that mRNA-1273 induces both potent neutralizing antibody and CD8 T cell responses and protects against SARS-CoV-2 infection in lungs and noses of mice without evidence of immunopathology. mRNA-1273 is currently in a Phase 2 clinical trial with a trajectory towards Phase 3 efficacy evaluation.

7.
Sci Transl Med ; 12(547)2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32522807

RESUMO

The emergence of Zika virus (ZIKV) in the Americas stimulated the development of multiple ZIKV vaccine candidates. We previously developed two related DNA vaccine candidates encoding ZIKV structural proteins that were immunogenic in animal models and humans. We sought to identify neutralizing antibody (NAb) properties induced by each vaccine that correlated with protection in nonhuman primates (NHPs). Despite eliciting equivalent NAb titers in NHPs, these vaccines were not equally protective. The transfer of equivalent titers of vaccine-elicited NAb into AG129 mice also revealed nonequivalent protection, indicating qualitative differences among antibodies (Abs) elicited by these vaccines. Both vaccines elicited Abs with similar binding titers against envelope protein monomers and those incorporated into virus-like particles, as well as a comparable capacity to orchestrate phagocytosis. Functional analysis of vaccine-elicited NAbs from NHPs and humans revealed a capacity to neutralize the structurally mature form of the ZIKV virion that varied in magnitude among vaccine candidates. Conversely, sensitivity to the virion maturation state was not a characteristic of NAbs induced by natural or experimental infection. Passive transfer experiments in mice revealed that neutralization of mature ZIKV virions more accurately predicts protection from ZIKV infection. These findings demonstrate that NAb correlates of protection may differ among vaccine antigens when assayed using standard neutralization platforms and suggest that measurements of Ab quality, including the capacity to neutralize mature virions, will be critical for defining correlates of ZIKV vaccine-induced immunity.

8.
bioRxiv ; 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32511338

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing an exponentially increasing number of coronavirus disease 19 (COVID-19) cases globally. Prioritization of medical countermeasures for evaluation in randomized clinical trials is critically hindered by the lack of COVID-19 animal models that enable accurate, quantifiable, and reproducible measurement of COVID-19 pulmonary disease free from observer bias. We first used serial computed tomography (CT) to demonstrate that bilateral intrabronchial instillation of SARS-CoV-2 into crab-eating macaques (Macaca fascicularis) results in mild-to-moderate lung abnormalities qualitatively characteristic of subclinical or mild-to-moderate COVID-19 (e.g., ground-glass opacities with or without reticulation, paving, or alveolar consolidation, peri-bronchial thickening, linear opacities) at typical locations (peripheral>central, posterior and dependent, bilateral, multi-lobar). We then used positron emission tomography (PET) analysis to demonstrate increased FDG uptake in the CT-defined lung abnormalities and regional lymph nodes. PET/CT imaging findings appeared in all macaques as early as 2 days post-exposure, variably progressed, and subsequently resolved by 6-12 days post-exposure. Finally, we applied operator-independent, semi-automatic quantification of the volume and radiodensity of CT abnormalities as a possible primary endpoint for immediate and objective efficacy testing of candidate medical countermeasures.

9.
Int J Infect Dis ; 98: 241-249, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32593623

RESUMO

OBJECTIVES: Dengue and Zika infections cause illnesses with overlapping clinical manifestations. The aim of this study was to explore the association of each of these infections with single or grouped clinical and laboratory parameters. METHODS: Clinical and laboratory data were collected prospectively from a cohort of patients seeking care for symptoms meeting the Pan American Health Organization's modified case-definition criteria for probable Zika virus infection. Zika and dengue were diagnosed with RT-PCR. The relationship of clinical characteristics and laboratory data with Zika, dengue, and undefined acute illness (UAI) was examined. RESULTS: In the univariate models, localized rash and maculopapular exanthema were associated with Zika infection. Generalized rash, petechiae, and petechial purpuric rash were associated with dengue. Cough and confusion/disorientation were associated with UAI. Platelets were significantly lower in the dengue group. A conditional inference tree model showed poor sensitivity and positive predictive value for individual viral diagnoses. CONCLUSIONS: Clusters of signs, symptoms, and laboratory values evaluated in this study could not consistently differentiate Zika or dengue cases from UAI in the clinical setting at the individual patient level. We identified symptoms that are important to Zika and dengue in the univariate analyses, but predictive models were unreliable. Low platelet count was a distinctive feature of dengue.


Assuntos
Dengue/epidemiologia , Infecção por Zika virus/epidemiologia , Doença Aguda/epidemiologia , Adolescente , Adulto , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Vírus da Dengue/fisiologia , Feminino , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem , Zika virus/genética , Zika virus/isolamento & purificação , Zika virus/fisiologia , Infecção por Zika virus/virologia
12.
Open Forum Infect Dis ; 7(1): ofaa017, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32016127

RESUMO

Immune reconstitution inflammatory syndrome (IRIS) is characterized by release of proinflammatory cytokines and tissue inflammation occurring early after antiretroviral therapy (ART) initiation. The role of previous IRIS events in persistent chronic inflammation in people with HIV is currently unclear. In this retrospective analysis of 143 participants who maintained suppression of HIV viremia, we compared biomarkers related to inflammation, coagulation, and cardiovascular risk after 3 years on ART in participants with and without a history of IRIS. There was no evidence of higher levels of persistent chronic inflammation in people with HIV who had a history of an IRIS event. ClinicalTrials.gov Identifier . NCT00286767.

14.
Clin Infect Dis ; 71(4): 1017-1021, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31532827

RESUMO

BACKGROUND: After scale-up of antiretroviral therapy (ART), routine annual viral load monitoring has been adopted by most countries, but reduced frequency of viral load monitoring may offer cost savings in resource-limited settings. We investigated if viral load monitoring frequency could be reduced while maintaining detection of treatment failure. METHODS: The Rakai Health Sciences Program performed routine, biannual viral load monitoring on 2489 people living with human immunodeficiency virus (age ≥15 years). On the basis of these data, we built a 2-stage simulation model to compare different viral load monitoring schemes. We fit Weibull regression models for time to viral load >1000 copies/mL (treatment failure), and simulated data for 10 000 individuals over 5 years to compare 5 monitoring schemes to the current viral load testing every 6 months and every 12 months. RESULTS: Among 7 monitoring schemes tested, monitoring every 6 months for all subjects had the fewest months of undetected failure but also had the highest number of viral load tests. Adaptive schemes using previous viral load measurements to inform future monitoring significantly decreased the number of viral load tests without markedly increasing the number of months of undetected failure. The best adaptive monitoring scheme resulted in a 67% reduction in viral load measurements, while increasing the months of undetected failure by <20%. CONCLUSIONS: Adaptive viral load monitoring based on previous viral load measurements may be optimal for maintaining patient care while reducing costs, allowing more patients to be treated and monitored. Future empirical studies to evaluate differentiated monitoring are warranted.

15.
J Infect Dis ; 221(5): 756-765, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31581292

RESUMO

BACKGROUND: Multiple factors influence the human immunodeficiency virus (HIV) antibody response produced during natural infection, leading to responses that can vary in specificity, strength, and breadth. METHODS: People who inject drugs identified as recently infected with HIV (n = 23) were analyzed for clustering of their viral sequences (genetic distance, <2%). Longitudinal antibody responses were identified for neutralizing antibody (Nab) potential, and differences in antibody subclass, specificity, and Fc receptor ligation using pseudovirus entry and multiplexed Fc array assays, respectively. Responses were analyzed for differences between subject groups, defined by similarity in the sequence of the infecting virus. RESULTS: Viral sequences from infected individuals were grouped into 3 distinct clusters with 7 unclustered individuals. Subjects in cluster 1 generally had lower antibody response magnitudes, except for antibodies targeting the V1/V2 region. Subjects in clusters 2 and 3 typically had higher antibody response magnitudes, with the Fv specificity of cluster 2 favoring gp140 recognition. NAb responses differed significantly between clusters for 3 of 18 pseudoviruses examined (P < .05), but there were no differences in overall NAb breadth (P = .62). DISCUSSION: These data demonstrate that individuals infected with similar viral strains can generate partially similar antibody responses, but these do not drastically differ from those in individuals infected with relatively unrelated strains.


Assuntos
Síndrome de Imunodeficiência Adquirida/complicações , Síndrome de Imunodeficiência Adquirida/epidemiologia , Epidemias , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Abuso de Substâncias por Via Intravenosa/complicações , Síndrome de Imunodeficiência Adquirida/imunologia , Síndrome de Imunodeficiência Adquirida/virologia , Adulto , Anticorpos Neutralizantes/imunologia , Baltimore/epidemiologia , Sequência de Bases/genética , Análise por Conglomerados , Feminino , Seguimentos , Proteína gp41 do Envelope de HIV/genética , HIV-1/genética , Humanos , Estudos Longitudinais , Masculino , Filogenia , Adulto Jovem , Produtos do Gene pol do Vírus da Imunodeficiência Humana/genética
16.
Clin Infect Dis ; 71(3): 652-660, 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-31504347

RESUMO

BACKGROUND: Patients living with human immunodeficiency virus (PLWH) with low CD4 counts are at high risk for immune reconstitution inflammatory syndrome (IRIS) and death at antiretroviral therapy (ART) initiation. METHODS: We investigated the clinical impact of IRIS in PLWH and CD4 counts <100 cells/µL starting ART in an international, prospective study in the United States, Thailand, and Kenya. An independent review committee adjudicated IRIS events. We assessed associations between baseline biomarkers, IRIS, immune recovery at week 48, and death by week 48 with Cox models. RESULTS: We enrolled 506 participants (39.3% were women). Median age was 37 years, and CD4 count was 29 cells/µL. Within 6 months of ART, 97 (19.2%) participants developed IRIS and 31 (6.5%) died. Participants with lower hemoglobin at baseline were at higher IRIS risk (hazard ratio [HR], 1.2; P = .004). IRIS was independently associated with increased risk of death after adjustment for known risk factors (HR, 3.2; P = .031). Being female (P = .004) and having a lower body mass index (BMI; P = .003), higher white blood cell count (P = .005), and higher D-dimer levels (P = .044) were also significantly associated with increased risk of death. Decision-tree analysis identified hemoglobin <8.5 g/dL as predictive of IRIS and C-reactive protein (CRP) >106 µg/mL and BMI <15.6 kg/m2 as predictive of death. CONCLUSIONS: For PLWH with severe immunosuppression initiating ART, baseline low BMI and hemoglobin and high CRP and D-dimer levels may be clinically useful predictors of IRIS and death risk.

17.
Science ; 365(6452): 505-509, 2019 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-31371616

RESUMO

Technologies that define the atomic-level structure of neutralization-sensitive epitopes on viral surface proteins are transforming vaccinology and guiding new vaccine development approaches. Previously, iterative rounds of protein engineering were performed to preserve the prefusion conformation of the respiratory syncytial virus (RSV) fusion (F) glycoprotein, resulting in a stabilized subunit vaccine candidate (DS-Cav1), which showed promising results in mice and macaques. Here, phase I human immunogenicity data reveal a more than 10-fold boost in neutralizing activity in serum from antibodies targeting prefusion-specific surfaces of RSV F. These findings represent a clinical proof of concept for structure-based vaccine design, suggest that development of a successful RSV vaccine will be feasible, and portend an era of precision vaccinology.


Assuntos
Imunogenicidade da Vacina , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/química , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano/imunologia , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/imunologia , Adolescente , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Mapeamento de Epitopos , Humanos , Pessoa de Meia-Idade , Adulto Jovem
18.
Cell ; 178(3): 567-584.e19, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31348886

RESUMO

The vaccine-mediated elicitation of antibodies (Abs) capable of neutralizing diverse HIV-1 strains has been a long-standing goal. To understand how broadly neutralizing antibodies (bNAbs) can be elicited, we identified, characterized, and tracked five neutralizing Ab lineages targeting the HIV-1-fusion peptide (FP) in vaccinated macaques over time. Genetic and structural analyses revealed two of these lineages to belong to a reproducible class capable of neutralizing up to 59% of 208 diverse viral strains. B cell analysis indicated each of the five lineages to have been initiated and expanded by FP-carrier priming, with envelope (Env)-trimer boosts inducing cross-reactive neutralization. These Abs had binding-energy hotspots focused on FP, whereas several FP-directed Abs induced by immunization with Env trimer-only were less FP-focused and less broadly neutralizing. Priming with a conserved subregion, such as FP, can thus induce Abs with binding-energy hotspots coincident with the target subregion and capable of broad neutralization.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Peptídeos/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/classificação , Linfócitos B/citologia , Linfócitos B/metabolismo , Cristalografia por Raios X , Feminino , Células HEK293 , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/classificação , HIV-1/metabolismo , Humanos , Macaca mulatta , Masculino , Peptídeos/química , Estrutura Terciária de Proteína , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo
19.
Sci Transl Med ; 11(499)2019 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-31270270

RESUMO

Public health emergencies, such as an Ebola disease outbreak, provide a complex and challenging environment for the evaluation of candidate vaccines. Here, we outline the need for flexible and responsive vaccine trial designs to be used in public health emergencies, and we summarize recommendations for their use in this setting.

20.
Lancet HIV ; 6(7): e475-e482, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31078451

RESUMO

Despite the recent success of antiretrovirals for HIV prevention, additional, more effective, or more acceptable biomedical interventions will ultimately be needed to end the HIV epidemic. Designing clinical trials to evaluate the efficacy of new products that reduce HIV infection risk is challenging because of the existence of highly effective interventions to prevent HIV. However, the implementation of these interventions is uneven, and the fact that multiple HIV prevention efficacy trials are currently evaluating new products means the field confronts uncertainty in the emerging standard of prevention. In this Viewpoint, we take stock of the current state of HIV prevention, and subsequently discuss the key challenges in designing future trials to evaluate the next generation of HIV prevention products. We also highlight gaps in the knowledge base that need to be addressed to advance the design of research. Future trials are tenable, even in the context of existing and effective interventions, and should involve careful statistical approaches and multidisciplinary collaborative design.

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