An animal model of covid-19 is now available

MICE ARE, as it were, the guinea pigs of science. And these days they are often genetically engineered guinea pigs, to boot. The emergence of covid-19, for example, has created demand for laboratory animals that have human versions of a protein called the ACE2 receptor. This molecule is the hook that SARS-CoV-2, the virus which causes covid-19, uses to attach itself to a cell before entering and turning that cell into a virus factory. The murine version of ACE2 is, however, the wrong shape for the virus to link up with. That means unmodified mice cannot catch the infection. Hence the need for genetic engineering.