Novel nanobody drug conjugate as a prophylactic or therapeutic against SARS-CoV-2 infection in mice.

The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, resulted in global health and economic crisis at an exceptional level. The high transmissibility of SARS-CoV-2, a lack of population immunity, and the prevalence of severe clinical outcomes created a need for the rapid development of effective therapeutic countermeasures. Sybodies, or synthetic nanobodies, are a novel and unique class of synthetic antigen-binding fragments ideal for large-scale production.