{"id":26969,"date":"2020-05-16T12:53:00","date_gmt":"2020-05-16T16:53:00","guid":{"rendered":"https:\/\/philip.greenspun.com\/blog\/?p=26969"},"modified":"2020-05-11T23:18:03","modified_gmt":"2020-05-12T03:18:03","slug":"only-about-1-7-percent-of-danes-had-covid-19-antibodies-back-in-april","status":"publish","type":"post","link":"https:\/\/philip.greenspun.com\/blog\/2020\/05\/16\/only-about-1-7-percent-of-danes-had-covid-19-antibodies-back-in-april\/","title":{"rendered":"Only about 1.7 percent of Danes had Covid-19 antibodies back in April"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/www.medrxiv.org\/content\/10.1101\/2020.04.24.20075291v1\">&#8220;Estimation of SARS-CoV-2 infection fatality rate by real-time antibody screening of blood donors&#8221;<\/a> (medRxiv; thanks, Colin!) describes testing donated blood in Denmark (nearly 10,000 samples) and finding that only 1.7 percent were positive for coronavirus antibodies. The blood had been donated April 6-17.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Does this mean that, now that the Danes are emerging from their bunkers, they will essentially start all over with a coronaplague? If 98 percent of the population has no immunity to plague, how is that different than if 100 percent of the population has no immunity (presumably, the situation back in December\/January)? If it wasn&#8217;t safe for people to mix back in mid-March, now that 2 percent of the population is presumed immune, it is suddenly safe?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">What do we make of this seemingly crazy low number for a purportedly exponentially growing disease that had at least two months to run free in Denmark? Here are some possibilities:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Except in certain high-density cities, coronaplague is not very contagious, nowhere near as ferocious as we were told<\/li><li>A lot of people simply aren&#8217;t susceptible to coronaplague, just as a lot of people won&#8217;t catch a cold that is going around, and, having never been truly infected, don&#8217;t develop antibodies<\/li><li>The antibody tests that we have are not reliable for determining if someone has previously been infected with coronaplague<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">[Another aspect of the paper that I suspect won&#8217;t interest anyone:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>Using available data on fatalities and population numbers a combined IFR in patients younger than 70 is estimated at 82 per 100,000 (CI: 59-154) infections.<\/p><\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">In other words, a person under 70 who actually does get infected with this evil virus has a 0.082% of dying (about the same as the annual risk of death from commuting via motorcycle 4,000 miles per year). Given the current popular mood, however, I think any number larger than 0% will be a sufficient justification for cowering in a bunker.]<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Some other studies in the most plague-ridden areas have found 20-30 percent of the adult population with antibodies. That too, however, suggests to me that a lot of people are somehow naturally immune.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Readers: Could Denmark have truly missed this first wave of plague?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Related:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><a href=\"https:\/\/judithcurry.com\/2020\/05\/10\/why-herd-immunity-to-covid-19-is-reached-much-earlier-than-thought\/\">&#8220;Why herd immunity to COVID-19 is reached much earlier than thought&#8221;<\/a> (models would kick out very different results if you assume that not everyone is a suitable host for coronavirus)<\/li><\/ul>\n","protected":false},"excerpt":{"rendered":"<p>&#8220;Estimation of SARS-CoV-2 infection fatality rate by real-time antibody screening of blood donors&#8221; (medRxiv; thanks, Colin!) describes testing donated blood in Denmark (nearly 10,000 samples) and finding that [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[61,52],"tags":[],"class_list":["post-26969","post","type-post","status-publish","format-standard","hentry","category-coronapanic","category-europe"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.3 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Only about 1.7 percent of Danes had Covid-19 antibodies back in April - Philip Greenspun\u2019s Weblog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/philip.greenspun.com\/blog\/2020\/05\/16\/only-about-1-7-percent-of-danes-had-covid-19-antibodies-back-in-april\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Only about 1.7 percent of Danes had Covid-19 antibodies back in April - Philip Greenspun\u2019s Weblog\" \/>\n<meta property=\"og:description\" content=\"&#8220;Estimation of SARS-CoV-2 infection fatality rate by real-time antibody screening of blood donors&#8221; 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