Novel protein construct prevents lethal COVID-19 in mice Researchers in the United States have developed a novel protein that prevented lethal disease among mice infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – the agent that causes coronavirus disease 2019 (COVID-19). The team engineered a soluble, short, and dimeric version of the native host cell receptor that is bound by a surface structure on SARS-CoV-2 called spike during the initial stage of the infection process. The team – from the Feinberg School of Medicine in Chicago, the University of Chicago, and Northwestern University in Evanston – suspected that a soluble, truncated version of this membrane-bound receptor – called angiotensin-converting enzyme 2 (ACE2) – would serve as a decoy for SARS-CoV-2 spike binding and potentially neutralize infection.