Pinpointing the animal origins of SARS-CoV-2: a genomic approach

Abstract

<p>Understanding the origins of zoonoses is critical to developing the means to prevent zoonotic spillover into the future. Like 60% of emerging diseases in humans (Jones et al., 2008), SARS-CoV-2 is likely to have zoonotic origins with possible immediate hosts (Holmes et al., 2021; Wang et al., 2021). Determination of the origin of SARS-CoV-2, that is, when, where, and how it emerges in humans through possible zoonotic transfer, facilitates prevention of the emergence and establishment of new zoonotic diseases. Yet, so far, whilst many similar CoVs have been detected in wild animals (especially bats), the SARS-CoV-2 progenitor has not been identified, and the closest wild hosts still host viruses estimated to have diverged from SARS-CoV-2 decades ago (Holmes et al., 2021). There have been two controversial speculations on the origin of SARS-CoV-2, the natural origin and the laboratory leak hypotheses (Burki, 2020). In understanding the probability of either theory, we should consider patterns from former epidemics, which all showed immediate spillover from wildlife, or livestock, and the similarity of coronaviruses found in wildlife in the region.<br></p>