Abstract WHO convened an Advisory Group (AG) to consider the feasibility, potential value and limitations of establishing a closely-monitored challenge model of experimental SARS-CoV-2 infection and COVID-19 in healthy adult volunteers. The AG included experts in design, establishment and performance of challenges. This report summarizes issues that render a COVID-19 model daunting to establish (SARS-CoV-2’s potential to cause severe/fatal illness, its high transmissibility, and lack of a “rescue treatment” to prevent progression from mild/moderate to severe clinical illness) and it proffers prudent strategies for stepwise model development, challenge virus selection, guidelines for manufacturing challenge doses, and ways to contain SARS-CoV-2 and prevent transmission to household/community contacts. A COVID-19 model could demonstrate protection against virus shedding and/or illness induced by prior SARS-CoV-2 challenge or vaccination. A limitation of the model is that vaccine efficacy in experimentally challenged healthy young adults cannot per se be extrapolated to predict efficacy in elderly/high-risk adults.
【저자키워드】 COVID-19, SARS-CoV-2, Challenge model, experimental challenge, adult volunteers, 【초록키워드】 Efficacy, Vaccine, vaccination, feasibility, SARS-COV-2 infection, Transmission, progression, virus, Adults, Transmissibility, WHO, group, predict, volunteers, limitation, doses, Prevent, lack, healthy, 【제목키워드】 challenge, Model, WHO, group, Establishing,