https://www.economist.com/science-and-technology/2020/07/22/the-hunt-for-the-origins-of-sars-cov-2-will-look-beyond-china
> The virus may have been born in South-East Asia > ONE OF THE great questions of the past six months is where SARS-CoV-2, the > virus that causes covid-19, came from. It is thought the answer involves > bats, because they harbour a variety of SARS-like viruses. Yunnan, one of > China’s southernmost provinces, has drawn the attention of virus hunters, as > the closest-known relatives of SARS-CoV-2 are found there. But some think the > origins of the virus are not to be found in China at all, but rather just > across the border in Myanmar, Laos or Vietnam. > > This is the hunch of Peter Daszak, head of EcoHealth Alliance, an > organisation which researches animals that harbour diseases that move into > people. Since the outbreak, in 2003, of the original SARS (now known as > SARS-CoV), scientists have paid close attention to coronaviruses. Dr Daszak > says that around 16,000 bats have been sampled and around 100 new SARS-like > viruses discovered. In particular, some bats found in China are now known to > harbour coronaviruses that seem pre-adapted to infect people. The chiropteran > hosts of these viruses have versions of a protein called ACE2 that closely > resemble the equivalent in people. This molecule is used by SARS-like viruses > as a point of entry into a cell. .... > Support for the idea that something resembling SARS-CoV-2 might have been > circulating in the region before the pandemic began also comes from another > intriguing observation: the low incidence of covid-19 in South-East Asia, > particularly in Vietnam. John Bell, a professor of medicine at the University > of Oxford, says everyone thought there would be a flood of cases in Vietnam > because the country is right across the border from China. Yet Vietnam has > reported only 300 in a population of 100m, and no deaths. The country did not > have a great lockdown either, he adds. Nobody could work out what was going > on. > > One explanation, he suggests, is that Vietnam’s population is not as > immunologically “naive” as has been assumed. The circulation of other > SARS-like viruses could have conferred a generalised immunity to such > pathogens. So, if a new one emerged in the region, it was able to take hold > in the human population only when it travelled all the way to central > China—where people did not have this natural resistance. -- Kim Holburn IT Network & Security Consultant T: +61 2 61402408 M: +61 404072753 mailto:[email protected] aim://kimholburn skype://kholburn - PGP Public Key on request _______________________________________________ Link mailing list [email protected] http://mailman.anu.edu.au/mailman/listinfo/link
