{"id":178925,"date":"2021-02-15T12:01:23","date_gmt":"2021-02-15T12:01:23","guid":{"rendered":"https:\/\/www.transcend.org\/tms\/?p=178925"},"modified":"2021-02-10T09:42:50","modified_gmt":"2021-02-10T09:42:50","slug":"why-the-flu-has-disappeared","status":"publish","type":"post","link":"https:\/\/www.transcend.org\/tms\/2021\/02\/why-the-flu-has-disappeared\/","title":{"rendered":"Why the Flu Has \u2018Disappeared\u2019"},"content":{"rendered":"

7 Feb 2021<\/em><\/p><\/blockquote>\n

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Global circulation of influenza viruses, 2018-2021 (WHO FluNet)<\/p><\/div>\n<\/figcaption><\/figure>\n

In 2020, after the global coronavirus pandemic began, influenza viruses mysteriously disappeared from global circulation (see WHO FluNet chart above). Some skeptics suspected that influenza was simply reclassified as covid, while many journalists and \u2018fact checkers\u2019 claimed influenza was suppressed by supereffective face masks and lockdowns.<\/p>\n

But influenza has not been reclassified as covid, and influenza viruses have disappeared even in countries without face masks and lockdowns, while they had not disappeared during previous epidemics and pandemics, despite face masks, school closures, and other measures.<\/p>\n

Instead, influenza viruses have simply been displaced by the more infectious novel coronavirus. This displacement effect is well known from previous influenza pandemics: the 1918 flu virus was displaced by the 1957 flu virus, which in turn was displaced by the 1968 flu virus (see chart<\/a>). The 2009 swine flu virus<\/a> temporarily displaced previous flu viruses, but eventually couldn\u2019t assert itself (see chart<\/a>). And even during the current coronavirus pandemic, more transmissible virus strains have repeatedly displaced<\/a> previous coronavirus strains.<\/p>\n

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A microscopic view of the influenza virus.
(IMAGE: Kat Masback, Flickr)<\/p><\/div>\n

Why do countries with no covid or with little covid \u2013 most of them islands \u2013 also have no influenza? Because they closed their borders early<\/a>. If you don\u2019t import coronavirus, you can\u2019t import influenza viruses, which normally oscillate between the northern and southern hemispheres.<\/p>\n

An interesting and open question is whether the novel coronavirus might permanently suppress some or all of the existing influenza virus strains. This might, at last, be a positive development.