"Human challenge study" from_date:2012

Changes in memory and cognition during the SARS-CoV-2 human challenge study.

Prevention of Respiratory Syncytial Virus Infection in Healthy Adults by a Single Immunization of Ad26.RSV.preF in a Human Challenge Study. Respiratory syncytial virus (RSV) is a significant cause of severe lower respiratory tract disease in children and older adults, but has no approved vaccine. This study assessed the potential of Ad26.RSV.preF to protect against RSV infection and disease

Public attitudes to a human challenge study with SARS-CoV-2: a mixed-methods study. Human challenge studies involve the deliberate exposure of healthy volunteers to an infectious micro-organism in a highly controlled and monitored way. They are used to understand infectious diseases and have contributed to the development of vaccines. In early 2020, the UK started exploring the feasibility of establishing a human challenge study with SARS-CoV-2. Given the significant public interest and the complexity of the potential risks and benefits, it is vital that public views are considered in the design and approval of any such study and that investigators and ethics boards remain accountable to the public. Mixed methods study comprising online surveys conducted with 2,441 UK adults and in-depth virtual

Immune response characterization in a human challenge study with a Shigella flexneri 2a bioconjugate vaccine. Diarrheal diseases are a leading cause of global morbidity and mortality affecting all ages, but especially children under the age of five in resource-limited settings. Shigella is a leading contributor to diarrheal diseases caused by bacterial pathogens and is considered a significant

Human challenge study with a Shigella bioconjugate vaccine: Analyses of clinical efficacy and correlate of protection. Shigellosis is a major cause of moderate to severe diarrhoea and dysentery in children under 5 years of age in low and middle-income countries. The Flexyn2a vaccine conjugates the O-polysaccharide of Shigella flexneri 2a to Pseudomonas aeruginosa exotoxin A. We describe a Phase

A Randomized, Placebo-Controlled, Respiratory Syncytial Virus Human Challenge Study of the Antiviral Efficacy, Safety, and Pharmacokinetics of RV521, an Inhibitor of the RSV-F Protein. Effective treatments for respiratory syncytial virus (RSV) infection are lacking. Here, we report a human proof-of-concept study for RV521, a small-molecule antiviral inhibitor of the RSV-F protein

Human Challenge Studies to Accelerate Coronavirus Vaccine Licensure. Controlled human challenge trials of SARS-CoV-2 vaccine candidates could accelerate the testing and potential rollout of efficacious vaccines. By replacing conventional phase 3 testing of vaccine candidates, such trials may subtract many months from the licensure process, making efficacious vaccines available more quickly

COVID-19 human challenge studies: ethical issues. COVID-19 poses an extraordinary threat to global public health and an effective vaccine could provide a key means of overcoming this crisis. Human challenge studies involve the intentional infection of research participants and can accelerate or improve vaccine development by rapidly providing estimates of vaccine safety and efficacy. Human challenge studies of low virulence coronaviruses have been done in the past and human challenge studies with severe acute respiratory syndrome coronavirus 2 have been proposed. These studies of coronaviruses could provide considerable benefits to public health; for instance, by improving and accelerating vaccine development. However, human challenge studies of severe acute respiratory syndrome coronavirus

Efficacy, immunogenicity, and safety of an oral influenza vaccine: a placebo-controlled and active-controlled phase 2 human challenge study. Influenza is an important public health problem and existing vaccines are not completely protective. New vaccines that protect by alternative mechanisms are needed to improve efficacy of influenza vaccines. In 2015, we did a phase 1 trial of an oral

Antiviral Activity, Safety, and Pharmacokinetics of AL-794, a Novel Oral Influenza Endonuclease Inhibitor: Results of an Influenza Human Challenge Study. AL-794 is an orally active prodrug of ALS-033719, which selectively inhibits the endonuclease domain of influenza virus A and B polymerase. In a phase 1, double-blinded, randomized, placebo-controlled study, healthy subjects were inoculated

Functional and Antigen-Specific Serum Antibody Levels as Correlates of Protection against Shigellosis in a Controlled Human Challenge Study Shigella is an important cause of diarrheal disease in young children living in developing countries. No approved vaccines are available, and the development of vaccine candidates has been hindered by the lack of firm immunological correlates of protection

A Human Challenge Study to Assess Protection of a Shigella Tetravalent Bioconjugate Vaccine In this challenge study, the bioconjugate candidate vaccine Shigella4V2 will be tested for its ability to induce an immune response that protects healthy adult volunteers from infection with a wild-type Shigella sonnei strain compared to participants receiving placebo. The tetravalent Shigella4V2

Singapore SARS-CoV-2 Human Challenge Study The goal of this study is to conduct a safe SARS-CoV-2 Delta variant human infection challenge in adult healthy volunteers. The main objectives are to: * Induce laboratory confirmed infection in up to 70% of participants* Confirm the safety profile as measured by the occurrence of adverse events (AEs) and serious adverse events (SAEs) from the day of viral challenge (Day 0) up to Day 28 follow-up. Participants will be given the GMP-produced Delta SARS-CoV-2 virus via intranasal drops using the optimized conditions established in the "Development of a SARS-CoV-2 Delta variant human infection challenge model" (COVHIC002) Human Challenge Study being conducted in the UK. A safe and well-tolerated human challenge model with the SARS-CoV-2 Delta variant

Deep Sequencing of Influenza A Virus from a Human Challenge Study Reveals a Selective Bottleneck and Only Limited Intrahost Genetic Diversification Knowledge of influenza virus evolution at the point of transmission and at the intrahost level remains limited, particularly for human hosts. Here, we analyze a unique viral data set of next-generation sequencing (NGS) samples generated from a human calculated pairwise genetic distances between the subjects' nasal wash samples, the viral stock, and the influenza virus A/Wisconsin/67/2005 (H3N2) reference strain used to generate the stock virus. These distances revealed that considerable viral evolution occurred at various points in the human challenge study. Further quantitative analyses indicated that (i) the viral stock contained genetic variants

Vomiting as a Symptom and Transmission Risk in Norovirus Illness: Evidence from Human Challenge Studies In the US, noroviruses are estimated to cause 21 million cases annually with economic losses reaching $2 billion. Outbreak investigations frequently implicate vomiting as a major transmission risk. However, little is known about the characteristics of vomiting as a symptom or the amount of virus present in emesis. Emesis samples and symptomology data were obtained from previous norovirus human challenge studies with GI.1 Norwalk virus, GII.2 Snow Mountain virus, and a pilot study with GII.1 Hawaii virus. Viral titers in emesis were determined using strain-specific quantitative RT-PCR. In all four studies, vomiting was common with 40-100% of infected subjects vomiting at least once

Periscope Phase C Bordetella Pertussis Human Challenge Study With Delayed Antibiotic Therapy for 6 Weeks Primary objective- To assess the safety of nasal inoculation of healthy volunteers with B. pertussis with antibiotic therapy given to eradicate colonisation at 6 weeks after inoculation or at symptom onset, whichever occurs firstSecondary objectives - To measure the rate of natural clearance - To identify biomarkers that correlate with natural clearance of B. pertussis carriage after induced B. pertussis colonisationTo detect transmission of B. pertussis to bedroom contacts of inoculated volunteers during prolonged asymptomatic colonisation This is a prospective controlled human challenge study; Challenge group: The challenge volunteers will be healthy volunteers, aged 18-55 years, not having

Evaluation of Dengue Virus strains for human challenge studies. Discordance between the measured levels of dengue virus neutralizing antibody and clinical outcomes in the first-ever efficacy study of a dengue tetravalent vaccine (Lancet, Nov 2012) suggests a need to re-evaluate the process of pre-screening dengue vaccine candidates to better predict clinical benefit prior to large-scale vaccine

Respiratory Syncytial Virus (RSV) Human Challenge Study of Molnupiravir in Healthy Participants (MK-4482-017) This is a phase 2A, double-blind, randomized, placebo-controlled study of molnupiravir (MK-4482) in healthy participants who have been inoculated with an experimental Respiratory Syncytial Virus (RSV) [RSV-A Memphis 37b]. It is hypothesized that MK-4482 will reduce the peak viral load

Human Challenge Study to Evaluate the Efficacy of MV-012-968 Vaccine The purpose of this research study is to evaluate whether the investigational, live attenuated, intranasally delivered vaccine MV-012-968 ('study vaccine') may have prophylactic efficacy against symptomatic RSV infection when administered to adults 18-45 years of age in the Human Viral Challenge model. undefined