Department of Politics and International Relations, University of Oxford, Oxford, United Kingdom.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA.
Clin Infect Dis. 2021 Feb 16;72(4):710-715. doi: 10.1093/cid/ciaa935.
Human challenge trials (HCTs) have been proposed as a means to accelerate SARS-CoV-2 vaccine development. We identify and discuss 3 potential use cases of HCTs in the current pandemic: evaluating efficacy, converging on correlates of protection, and improving understanding of pathogenesis and the human immune response. We outline the limitations of HCTs and find that HCTs are likely to be most useful for vaccine candidates currently in preclinical stages of development. We conclude that, while currently limited in their application, there are scenarios in which HCTs would be extremely beneficial. Therefore, the option of conducting HCTs to accelerate SARS-CoV-2 vaccine development should be preserved. As HCTs require many months of preparation, we recommend an immediate effort to (1) establish guidelines for HCTs for COVID-19; (2) take the first steps toward HCTs, including preparing challenge virus and making preliminary logistical arrangements; and (3) commit to periodically re-evaluating the utility of HCTs.
人类挑战试验（HCT）被提议作为加速 SARS-CoV-2 疫苗开发的一种手段。我们确定并讨论了当前大流行中 HCT 的 3 种潜在用途：评估疗效、趋同保护相关因素，以及加深对发病机制和人类免疫反应的理解。我们概述了 HCT 的局限性，并发现 HCT 最有可能对处于临床前开发阶段的疫苗候选物最有用。我们的结论是，尽管目前应用有限，但在某些情况下 HCT 将非常有益。因此，应该保留进行 HCT 以加速 SARS-CoV-2 疫苗开发的选择。由于 HCT 需要数月的准备，我们建议立即努力：（1）为 COVID-19 制定 HCT 指南；（2）朝着 HCT 迈出第一步，包括准备挑战病毒和做出初步后勤安排；（3）承诺定期重新评估 HCT 的效用。
