{"id":156785,"date":"2020-03-30T12:00:29","date_gmt":"2020-03-30T11:00:29","guid":{"rendered":"https:\/\/www.transcend.org\/tms\/?p=156785"},"modified":"2020-12-02T10:20:25","modified_gmt":"2020-12-02T10:20:25","slug":"seven-important-things-to-know-about-coronaviruses","status":"publish","type":"post","link":"https:\/\/www.transcend.org\/tms\/2020\/03\/seven-important-things-to-know-about-coronaviruses\/","title":{"rendered":"Seven Important Things to Know about Coronaviruses"},"content":{"rendered":"<blockquote><p>20 Mar 2020 &#8211; Six<em> reasons they\u2019re so harmful, and one reason they\u2019re less infectious than other diseases.<\/em><\/p><\/blockquote>\n<div style=\"width: 1080px;\" class=\"wp-video\"><video class=\"wp-video-shortcode\" id=\"video-156785-1\" width=\"1080\" height=\"1080\" preload=\"metadata\" controls=\"controls\"><source type=\"video\/mp4\" src=\"https:\/\/www.transcend.org\/tms\/wp-content\/uploads\/2020\/03\/coronavirus-cartoon.mp4?_=1\" \/><a href=\"https:\/\/www.transcend.org\/tms\/wp-content\/uploads\/2020\/03\/coronavirus-cartoon.mp4\" >https:\/\/www.transcend.org\/tms\/wp-content\/uploads\/2020\/03\/coronavirus-cartoon.mp4<\/a><\/video><\/div>\n<div class=\"css-1fanzo5 StoryBodyCompanionColumn\">\n<div class=\"css-53u6y8\">\n<p class=\"css-exrw3m evys1bk0\">In the past two decades, coronaviruses have produced three deadly global epidemics: SARS, MERS and now Covid-19. If you\u2019re wondering what it is about this family of viruses that makes it produce such deadly pathogens \u2014 and what about them might hinder their spread \u2014 here are a few things you should know.<\/p>\n<p class=\"css-exrw3m evys1bk0\"><strong class=\"css-8qgvsz ebyp5n10\">1. They have a high substitution rate.<\/strong><\/p>\n<p class=\"css-exrw3m evys1bk0\">Coronaviruses have, like many RNA viruses, a <a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/15709046\" class=\"css-1g7m0tk\" title=\"\"  target=\"_blank\" rel=\"noopener noreferrer\">high substitution rate<\/a> (though the rate is lower than some other viruses that have caused pandemics, like HIV or hepatitis C). This higher substitution rate means that coronaviruses can rapidly exploit situations in which they come into contact with new hosts (i.e., humans).<\/p>\n<p class=\"css-exrw3m evys1bk0\"><strong class=\"css-8qgvsz ebyp5n10\">2. They mutate rapidly.<\/strong><\/p>\n<p class=\"css-exrw3m evys1bk0\">One reason coronaviruses mutate so rapidly is that they possess <a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3185738\/\" class=\"css-1g7m0tk\" title=\"\"  target=\"_blank\" rel=\"noopener noreferrer\">the longest genomes of all known RNA viruses<\/a>. With more sections in their genome, there are more potential errors when the virus copies itself, which increases the production of new strains (which may explain the recent finding that there are likely to be <a href=\"https:\/\/www.newscientist.com\/article\/2236544-coronavirus-are-there-two-strains-and-is-one-more-deadly\/\" class=\"css-1g7m0tk\" title=\"\"  target=\"_blank\" rel=\"noopener noreferrer\">multiple Covid-19 strains<\/a>).<\/p>\n<p class=\"css-exrw3m evys1bk0\"><strong class=\"css-8qgvsz ebyp5n10\">3. They are highly susceptible to recombination.<\/strong><\/p>\n<p class=\"css-exrw3m evys1bk0\">One of the ways viral strains emerge is through recombination, which is when multiple viruses interact in the same organism (e.g., humans) during replication. Research predating the emergence of Covid-19 has shown that, of all the many coronavirus strains that are out there, a human coronavirus known as HCoV-HKU1 is among those most <a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3185738\/\" class=\"css-1g7m0tk\" title=\"\"  target=\"_blank\" rel=\"noopener noreferrer\">highly susceptible to recombination<\/a>. It is also one of the coronaviruses most closely related to Covid-19, along with SARS and MERS: all are members of the subset of betacoronaviruses.<\/p>\n<\/div>\n<aside class=\"css-ew4tgv\" aria-label=\"companion column\"><\/aside>\n<\/div>\n<div class=\"css-1fanzo5 StoryBodyCompanionColumn\">\n<div class=\"css-53u6y8\">\n<p class=\"css-exrw3m evys1bk0\"><strong class=\"css-8qgvsz ebyp5n10\">4. They replicate in multiple species.<\/strong><\/p>\n<p class=\"css-exrw3m evys1bk0\">Coronaviruses are also <a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC1951313\/\" class=\"css-1g7m0tk\" title=\"\"  target=\"_blank\" rel=\"noopener noreferrer\">exceptionally adaptive and able to replicate in different species<\/a>. Some viruses, like smallpox, can only infect one species. Coronaviruses can infect \u2014 at minimum \u2014 humans, bats, pigs, cattle, mice, chickens, civet cats, raccoon dogs, ferret badgers and camels, meaning they have what epidemiologists call \u201cbroad host range.\u201d This increases their spread across environments and makes them a lot harder to contain.<\/p>\n<p class=\"css-exrw3m evys1bk0\"><strong class=\"css-8qgvsz ebyp5n10\">5. They love bats.<\/strong><\/p>\n<p class=\"css-exrw3m evys1bk0\">While scientists suspect that Covid-19 may have initially jumped from bats to humans, bats seem to be uniquely able to harbor many viruses that cause serious human disease: Ebola, Marburg, Rabies, Hendra and Nipah. We can now add Covid-19 to that list. As recently as 2017, a <a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/28077633\" class=\"css-1g7m0tk\" title=\"\"  target=\"_blank\" rel=\"noopener noreferrer\">research study<\/a> that tested bats in Kenya identified several novel coronaviruses that had genomic sequences closely related to human coronaviruses. Why does this matter? This was a one-off research experiment and yet it showed that novel coronaviruses are constantly being discovered in bats.<\/p>\n<p class=\"css-exrw3m evys1bk0\"><strong class=\"css-8qgvsz ebyp5n10\">6. They\u2019ve been around (and evolving) for a long time.<\/strong><\/p>\n<p class=\"css-exrw3m evys1bk0\">Finally, molecular clock analysis is a technique that uses the mutation rate of viruses to determine when separate strains branched off from common ancestors. When an analysis was done on one of the four known human coronavirus (HCoV-229E, which causes the common cold), scientists discovered that it has been present in the human population for centuries. They were even able to <a href=\"https:\/\/www.researchgate.net\/publication\/232612295_Molecular_characterization_of_human_coronavirus_NL63\" class=\"css-1g7m0tk\" title=\"\"  target=\"_blank\" rel=\"noopener noreferrer\">estimate the specific year that it emerged<\/a>: 1053 AD, which is when it likely branched off from a viral ancestor to become its own strain.<\/p>\n<p class=\"css-exrw3m evys1bk0\"><strong class=\"css-8qgvsz ebyp5n10\">7. They\u2019re heavier than other viruses.<\/strong><\/p>\n<p class=\"css-exrw3m evys1bk0\">And, finally, the good news. While Covid-19 spreads through the air on <a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S0924857920300674\" class=\"css-1g7m0tk\" title=\"\"  target=\"_blank\" rel=\"noopener noreferrer\">respiratory droplets<\/a>, there is one fact limiting how far the virus can travel: its weight. Coronaviruses are physically larger and heavier than other known respiratory viruses. So while Covid-19 infects hosts via mucus droplets, its infectious range is lower relative to other viruses because its mass limits how far it can travel before succumbing to gravity. Case in point, coronaviruses can only travel about one to two meters, less than seven feet, <a href=\"https:\/\/www.livescience.com\/coronavirus-can-spread-as-an-aerosol.html\" class=\"css-1g7m0tk\" title=\"\"  target=\"_blank\" rel=\"noopener noreferrer\">before they start falling to the ground<\/a>. Compare that to much more infectious viruses like measles or chickenpox, both of which are much lighter and able to remain airborne on tiny dust particles.<\/p>\n<p>_____________________________________________<\/p>\n<p class=\"css-jwz2nf etfikam0\" style=\"padding-left: 40px;\"><em>Dr. Werb is an epidemiologist and author of <\/em>City of Omens: A Search for the Missing Women of the Borderlands.<\/p>\n<p class=\"css-jwz2nf etfikam0\" style=\"padding-left: 40px;\"><em> Dr. Davey Smith at the University of California San Diego<\/em><em> and Dr. Chris Mackie at McMaster University contributed virological insight.<\/em><\/p>\n<p><a target=\"_blank\" href=\"https:\/\/www.nytimes.com\/2020\/03\/20\/opinion\/coronavirus-facts.html\" >Go to Original &#8211; nytimes.com<\/a><\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>20 Mar 2020 &#8211; Six reasons they\u2019re so harmful, and one reason they\u2019re less infectious than other diseases.<\/p>\n","protected":false},"author":4,"featured_media":156415,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2236],"tags":[1829,289,1698,710,1864,1102,304,1447,339,124,1836,75],"class_list":["post-156785","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-covid19-coronavirus","tag-coronavirus","tag-economy","tag-epidemics","tag-health","tag-pandemic","tag-public-health","tag-science","tag-science-and-medicine","tag-trade","tag-united-nations","tag-who","tag-world"],"_links":{"self":[{"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/posts\/156785","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/comments?post=156785"}],"version-history":[{"count":0,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/posts\/156785\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/media\/156415"}],"wp:attachment":[{"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/media?parent=156785"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/categories?post=156785"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.transcend.org\/tms\/wp-json\/wp\/v2\/tags?post=156785"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}