How the zoonotic origins of SARS-CoV-2 ensure its survival as a human disease

Four years after the last emergent epidemic of zoonotic SARS-coronavirus in 2003, researchers at the University of Hong Kong asked if the world was ready for the re-emergence of SARS (Cheng et al, 2007).

Despite over 4000 publications since 2003, the assessment highlighted the persistent gaps in scientific achievement relating to the perception of zoonotic coronaviruses. Up until 6 months ago, this evaluation in the face of anticipated further epidemics of a coronavirus still held true (Cheng et al, 2007; Mubarak et al, 2019).

This article-the second in a series on the science behind the pandemic-explores the opportunities for learning from previous human epidemics of coronaviruses and highlights the unintended consequences of underestimating the evolutionary aptitude of this family of viruses to ensure species survival into the next generation.

Zoonoses may be bacterial, viral or parasitic and are defined as any disease or infection that is naturally transmissible from a vertebrate species to humans (WHO, 2020). Zoonoses, as with many infections, can be transmitted through direct contact or indirectly via food, water or the environment. It is estimated that <0.1% of animal viruses are zoonotic with some inherent ability to replicate in humans (Warren and Sawyer, 2019).