Mohak Sharda, NCBS-TIFR
A comparison of coronaviruses present in different animals have suggested that bats and pangolins are the most recent intermediaries in the origin of SARS-CoV2. Six mutations in the viral protein required for human-ACE2 protein binding are identical in Pangolin-CoV and SARS-CoV2 but differ by four mutations in Bat-CoV. These mutations cause weaker binding to the human protein when compared to the previously studied 2003 SARS-CoV sequence. This suggests that it is highly unlikely that the current pandemic was a result of purposeful manipulations. A lack of previous studies reporting any progenitors of SARS-CoV2 further reduces the possibility of an inadvertent laboratory release of the virus. Instead two most likely explanations of origin, both explained by natural selection, emerge: 1) the virus adapted in an animal host highly similar to humans before transferring into the latter and/or 2) the SARS-CoV2 viral progenitor jumped into humans first and acquired the desired features to adapt during undetected human to human transmissions.
This is only one example of infections moving from animals to humans, and re-emphasises the importance of “one-health”, which aims to achieve “optimal health outcomes recognizing the interconnection between people, animals, plants, and their shared environment”.
- Andersen et al., The proximal origin of SARS-CoV-2(link is external), Nature (March 2020)
- Li et al., Emergence of SARS-CoV-2 through Recombination and Strong Purifying Selection(link is external), bioRxiv (2020)
- Weston and Frieman, COVID-19: Knowns, Unknowns, and Questions(link is external), mSphere (2020)
- Bhatia, Need for integrated surveillance at human-animal interface for rapid detection & response to emerging coronavirus infections using One Health approach(link is external), IJMR (2020)
- One Health Basics(link is external), CDC
[Last update 11 May 2020]