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Morrison H, Jackson S, McShane H. Controlled human infection models in COVID-19 and tuberculosis: current progress and future challenges. Front Immunol 2023; 14:1211388. [PMID: 37304270 PMCID: PMC10248465 DOI: 10.3389/fimmu.2023.1211388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 05/09/2023] [Indexed: 06/13/2023] Open
Abstract
Controlled Human Infection Models (CHIMs) involve deliberately exposing healthy human volunteers to a known pathogen, to allow the detailed study of disease processes and evaluate methods of treatment and prevention, including next generation vaccines. CHIMs are in development for both tuberculosis (TB) and Covid-19, but challenges remain in their ongoing optimisation and refinement. It would be unethical to deliberately infect humans with virulent Mycobacteria tuberculosis (M.tb), however surrogate models involving other mycobacteria, M.tb Purified Protein Derivative or genetically modified forms of M.tb either exist or are under development. These utilise varying routes of administration, including via aerosol, per bronchoscope or intradermal injection, each with their own advantages and disadvantages. Intranasal CHIMs with SARS-CoV-2 were developed against the backdrop of the evolving Covid-19 pandemic and are currently being utilised to both assess viral kinetics, interrogate the local and systemic immunological responses post exposure, and identify immune correlates of protection. In future it is hoped they can be used to assess new treatments and vaccines. The changing face of the pandemic, including the emergence of new virus variants and increasing levels of vaccination and natural immunity within populations, has provided a unique and complex environment within which to develop a SARS-CoV-2 CHIM. This article will discuss current progress and potential future developments in CHIMs for these two globally significant pathogens.
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Song Q, Wang L, Chen Y, Dan W, Dan N. Oxidized cyclodextrin inclusion tea tree oil to prepare long‐lasting antibacterial collagen scaffold for enhanced wound healing. J Appl Polym Sci 2022. [DOI: 10.1002/app.52139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Qiantao Song
- National Engineering Research Center of Clean Technology in Leather Industry Sichuan University Chengdu China
- Key Laboratory of Leather Chemistry and Engineering of Ministry of Education Sichuan University Chengdu China
- College of Biomass Science and Engineering Sichuan University Chengdu China
| | - Lu Wang
- National Engineering Research Center of Clean Technology in Leather Industry Sichuan University Chengdu China
- Key Laboratory of Leather Chemistry and Engineering of Ministry of Education Sichuan University Chengdu China
- College of Biomass Science and Engineering Sichuan University Chengdu China
| | - Yining Chen
- National Engineering Research Center of Clean Technology in Leather Industry Sichuan University Chengdu China
- Key Laboratory of Leather Chemistry and Engineering of Ministry of Education Sichuan University Chengdu China
- College of Biomass Science and Engineering Sichuan University Chengdu China
| | - Weihua Dan
- National Engineering Research Center of Clean Technology in Leather Industry Sichuan University Chengdu China
- Key Laboratory of Leather Chemistry and Engineering of Ministry of Education Sichuan University Chengdu China
- College of Biomass Science and Engineering Sichuan University Chengdu China
| | - Nianhua Dan
- National Engineering Research Center of Clean Technology in Leather Industry Sichuan University Chengdu China
- Key Laboratory of Leather Chemistry and Engineering of Ministry of Education Sichuan University Chengdu China
- College of Biomass Science and Engineering Sichuan University Chengdu China
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Baylor NW. Human Challenge Studies for Vaccine Development : Regulatory Aspects of Human Challenge Studies. Curr Top Microbiol Immunol 2021. [PMID: 34480650 DOI: 10.1007/82_2021_239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The traditional regulatory pathway for the evaluation of new vaccine candidates generally proceeds from preclinical through three successive phases of human trials, and the demonstration of efficacy is usually done through randomized-controlled clinical trials. However, human challenge trials or controlled human infection models have been used in vaccine clinical development to generate supportive data for establishment of correlates of protection, supportive data for licensure, as well as licensure in the case of Vaxchora® by the US FDA. Despite this, there are no codified regulations from national regulatory authorities (NRAs) that specifically address HCTs, nor guidance related to standardization of approaches to HCTs among regulators. NRAs may agree that HCTs are innovative, promising tools to accelerate vaccine development; however, a strong benefit/risk assessment is needed to ensure the safety of study participants. Lastly, it is important to consider the regulatory framework in which the human challenge trial may be conducted.
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Manheim D, Wiȩcek W, Schmit V, Morrison J. Exploring Risks of Human Challenge Trials For COVID-19. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2021; 41:710-720. [PMID: 33942351 PMCID: PMC8207107 DOI: 10.1111/risa.13726] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Human challenge trials (HCTs) are a potential method to accelerate development of vaccines and therapeutics. However, HCTs for COVID-19 pose ethical and practical challenges, in part due to the unclear and developing risks. In this article , we introduce an interactive model for exploring some risks of a severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) dosing study, a prerequisite for any COVID-19 challenge trials. The risk estimates we use are based on a Bayesian evidence synthesis model which can incorporate new data on infection fatality risks (IFRs) to patients, and infer rates of hospitalization. The model estimates individual risk, which we then extrapolate to overall mortality and hospitalization risk in a dosing study. We provide a web tool to explore risk under different study designs. Based on the Bayesian model, IFR for someone between 20 and 30 years of age is 15.1 in 100,000, with a 95% uncertainty interval from 11.8 to 19.2, while risk of hospitalization is 130 per 100,000 (100-160). However, risk will be reduced in an HCT via screening for comorbidities, selecting lower-risk population, and providing treatment. Accounting for this with stronger assumptions, we project the fatality risk to be as low as 2.5 per 100,000 (1.6-3.9) and the hospitalization risk to be 22.0 per 100,000 (14.0-33.7). We therefore find a 50-person dosing trial has a 99.74% (99.8-99.9%) chance of no fatalities, and a 98.9% (98.3-99.3%) probability of no cases requiring hospitalization.
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Affiliation(s)
- David Manheim
- 1DaySooner, Wilmington, DE, USA
- Health and Risk Communication Research Center, University of Haifa, School of Public Health, Haifa, Israel
| | - Witold Wiȩcek
- 1DaySooner, Wilmington, DE, USA
- WAW Statistical Consulting Ltd., UK
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Abstract
In this Comment article, Sandy Douglas and Adrian Hill discuss the immunological considerations associated with a risk–benefit analysis for controlled human infection models of SARS-CoV-2.
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Affiliation(s)
- Alexander D Douglas
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Adrian V S Hill
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Grady C, Shah S, Miller F, Danis M, Nicolini M, Ochoa J, Taylor H, Wendler D, Rid A. So much at stake: Ethical tradeoffs in accelerating SARSCoV-2 vaccine development. Vaccine 2020; 38:6381-6387. [PMID: 32826103 PMCID: PMC7418641 DOI: 10.1016/j.vaccine.2020.08.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND A sense of urgency exists to develop vaccines against SARS CoV-2, responsible for numerous global cases and deaths, as well as widespread social and economic disruption. Multiple approaches have been proposed to speed up vaccine development, including accelerated randomized controlled trials (RCT), controlled human challenge trials (CHI), and wide distribution through an emergency use authorization after collecting initial data. There is a need to examine how best to accelerate vaccine development in the setting of a pandemic, without compromising ethical and scientific norms. METHODS Trade-offs in scientific and social value between generating reliable evidence about safety and efficacy while promoting rapid vaccine availability are examined along five ethically relevant dimensions: (1) confidence in and generalizability of data, (2) feasibility, (3) speed and cost, (4) participant risks, and (5) social risks. RESULTS Accelerated individually randomized RCTs permit expeditious evaluation of vaccine candidates using established methods, expertise, and infrastructure. RCTs are more likely than other approaches to be feasible, increase speed and reduce cost, and generate reliable data about safety and efficacy without significantly increasing risks to participants or undermining societal trust. CONCLUSION Ethical analysis suggests that accelerated RCTs are the best approach to accelerating vaccine development in a pandemic, and more likely than other approaches to enhance social value without compromising ethics or science. RCTs can expeditiously collect rigorous data about vaccine safety and efficacy. Innovative and flexible designs and implementation strategies to respond to shifting incidence and test vaccine candidates in parallel or sequentially would add value, as will coordinated data sharing across vaccine trials. CHI studies may be an important complementary strategy when more is known. Widely disseminating a vaccine candidate without efficacy data will not serve the public health nor achieve the goal of identifying safe and effective SARS Co-V-2 vaccines.
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Affiliation(s)
- Christine Grady
- Department of Bioethics, National Institutes of Health Clinical Center, Building 10/1C118, NIH, Bethesda, MD 20892, United States.
| | - Seema Shah
- Lurie Children's Hospital, Northwestern University, Department of Pediatrics, 225 E. Chicago Ave, Chicago, IL 60611, United States.
| | - Franklin Miller
- Weill Cornell Medical College, Weill Cornell Medical College, 1300 York Ave, New York, NY 10065, United States.
| | - Marion Danis
- Department of Bioethics, National Institutes of Health Clinical Center, Building 10/1C118, NIH, Bethesda, MD 20892, United States.
| | - Marie Nicolini
- Department of Bioethics, National Institutes of Health Clinical Center, Building 10/1C118, NIH, Bethesda, MD 20892, United States.
| | - Jorge Ochoa
- Department of Bioethics, National Institutes of Health Clinical Center, Building 10/1C118, NIH, Bethesda, MD 20892, United States.
| | - Holly Taylor
- Department of Bioethics, National Institutes of Health Clinical Center, Building 10/1C118, NIH, Bethesda, MD 20892, United States.
| | - Dave Wendler
- Department of Bioethics, National Institutes of Health Clinical Center, Building 10/1C118, NIH, Bethesda, MD 20892, United States.
| | - Annette Rid
- Department of Bioethics, National Institutes of Health Clinical Center, Building 10/1C118, NIH, Bethesda, MD 20892, United States.
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Shah SK, Miller FG, Darton TC, Duenas D, Emerson C, Lynch HF, Jamrozik E, Jecker NS, Kamuya D, Kapulu M, Kimmelman J, MacKay D, Memoli MJ, Murphy SC, Palacios R, Richie TL, Roestenberg M, Saxena A, Saylor K, Selgelid MJ, Vaswani V, Rid A. Unnecessary hesitancy on human vaccine tests-Response. Science 2020; 369:151. [PMID: 32646992 DOI: 10.1126/science.abc9380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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