New from Nature Microbiology:
https://www.nature.com/articles/s41564-020-0771-4
Taken from the discussion:
This paper details the following :
1) the natural (not man-made) source of SARS-CoV-2 is bats, as expected and the virus has been around for a while
2) we failed to find it with our limited surveillance program
3) there could be other SARS-CoV-2-like viruses out there in specific regions of China, waiting to make the jump to other mammalian hosts or humans that could cause the next pandemic
In April, our brilliant government decided to cut NIH funding to a US non-profit aimed at doing just this type of surveillance work because they collaborated with the Wuhan Institute of Virology, based on unfounded conspiracy theories that the virus was either man-made or leaked from the lab.
That decision was wrong, not based on facts, and the paper above highlights how critical this type of surveillance work is so we can detect the next pandemic before it arrives. If there is one thing to learn from this mess, its that we are not funding and doing enough preventative field work to find these novel pathogens before they reach humans. We need to support this type of work, restore funding and get people out in the field TODAY.
Quote:
There are outstanding evolutionary questions on the recent emergence of human coronavirus SARS-CoV-2 including the role of reservoir species, the role of recombination and its time of divergence from animal viruses. We find that the sarbecovirusesthe viral subgenus containing SARS-CoV and SARS-CoV-2undergo frequent recombination and exhibit spatially structured genetic diversity on a regional scale in China. SARS-CoV-2 itself is not a recombinant of any sarbecoviruses detected to date, and its receptor-binding motif, important for specificity to human ACE2 receptors, appears to be an ancestral trait shared with bat viruses and not one acquired recently via recombination. To employ phylogenetic dating methods, recombinant regions of a 68-genome sarbecovirus alignment were removed with three independent methods. Bayesian evolutionary rate and divergence date estimates were shown to be consistent for these three approaches and for two different prior specifications of evolutionary rates based on HCoV-OC43 and MERS-CoV. Divergence dates between SARS-CoV-2 and the bat sarbecovirus reservoir were estimated as 1948 (95% highest posterior density (HPD): 18791999), 1969 (95% HPD: 19302000) and 1982 (95% HPD: 19482009), indicating that the lineage giving rise to SARS-CoV-2 has been circulating unnoticed in bats for decades.
https://www.nature.com/articles/s41564-020-0771-4
Taken from the discussion:
Quote:
Given what was known about the origins of SARS, as well as identification of SARS-like viruses circulating in bats that had binding sites adapted to human receptors29,30,31, appropriate measures should have been in place for immediate control of outbreaks of novel coronaviruses. The key to successful surveillance is knowing which viruses to look for and prioritizing those that can readily infect humans47.
This long divergence period suggests there are unsampled virus lineages circulating in horseshoe bats that have zoonotic potential due to the ancestral position of the human-adapted contact residues in the SARS-CoV-2 RBD. Without better sampling, however, it is impossible to estimate whether or how many of these additional lineages exist.
It is clear from our analysis that viruses closely related to SARS-CoV-2 have been circulating in horseshoe bats for many decades. The unsampled diversity descended from the SARS-CoV-2/RaTG13 common ancestor forms a clade of bat sarbecoviruses with generalist propertieswith respect to their ability to infect a range of mammalian cellsthat facilitated its jump to humans and may do so again.
This paper details the following :
1) the natural (not man-made) source of SARS-CoV-2 is bats, as expected and the virus has been around for a while
2) we failed to find it with our limited surveillance program
3) there could be other SARS-CoV-2-like viruses out there in specific regions of China, waiting to make the jump to other mammalian hosts or humans that could cause the next pandemic
In April, our brilliant government decided to cut NIH funding to a US non-profit aimed at doing just this type of surveillance work because they collaborated with the Wuhan Institute of Virology, based on unfounded conspiracy theories that the virus was either man-made or leaked from the lab.
That decision was wrong, not based on facts, and the paper above highlights how critical this type of surveillance work is so we can detect the next pandemic before it arrives. If there is one thing to learn from this mess, its that we are not funding and doing enough preventative field work to find these novel pathogens before they reach humans. We need to support this type of work, restore funding and get people out in the field TODAY.
