How Do Zoonotic Viruses Make An Inter-Species Jump?

Zoonotic diseases like influenza and many coronaviruses start out in animals, but their biological machinery often enables them to jump to humans.
MERS-CoV and SARS-CoV appear to originate in animals, and the same is likely true of SARS-CoV-2. This makes them zoonoses, diseases that can jump between humans and other animals.
While the specifics differ, the viral mechanism relies on the same fundamental premise: access and ability.

An article in Science Focus, written by Katherine Arden,...