So of the 3 kinds of influenza A, B, and C, only A causes pandemics apparently. There’s also a 4th kind added recently. It was hard to prove because viruses can’t be cultured like bacteria, in a Petri dish. Only inside living cells.
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Anybody think about how Trump’s wall idea is just a country scale mask against people he thinks of as diseases? Some 4d irony there that I don’t have the energy to unpack. Wear masks, don’t build walls.
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So flu equilibriums last about a human lifespan. Once populations get “immunologically naive” another pandemic can happen. 1968 Hong Kong flu was possibly 1890 Russian flu, and 2009 H1N1 was apparently 1918 Spanish Flu.
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There’s an eerie echo here in outbreaks of totalitarianism. Despite “never forget” culture re Holocaust, 2010s had become immunologically naive to perils of totalitarianism. Even though Trumpism mind flu is an attentuated strain, it’s descended from Hitlerism mind flu of 1933.
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There are apparently 18 kinds of H and 11 kinds of N. So you could potentially have a flu called H18N11
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And that’s not even counting strains.
We should just give up and stop living in dense cities. This doesn’t seem very winnable long term.
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Ok that’s 13 chapters done. Next one ominously titled “beware the barnyard.” Bedtime horror story resumes tomorrow. Try not to pet bats and ferrets and chickens ok.
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Footnote to tonight’s notes... defeatism here is not just me. I’ve heard a popular theory that the century of gains against infectious disease was entirely based on temporary victories. Individual battles are won but the war overall gets harder and we are steadily losing ground.
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Well, let’s get back to this grim fairy tale. The story of crossover. Apparently duck guts are the natural reservoir of flu viruses and that’s been known since the 1970s. I’ll never look at ducks the same. Wonder what species stores coronaviruses
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They used to think flus needed to go from birds to humans by way of pigs (which would make the French origin hypothesis the likeliest for various reasons) but H5N1 in 1997 in Hong Kong showed it could jump direct. Could that have happened in 1918?
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After partial sequencing from rare preserved samples in the late 90s, researchers managed to get better permafrost-preserved samples from Alaskan mass graves. In 2005 Ann Reid and Jeffrey Taubenberger finally sequenced the full genome after 9 years of detective work.


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Damn 87 years later. Gotta love the deep historical detective work. They resurrected the virus in the lab and showed it was very bird-like. No pigs needed in transmission chain.
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1918 flu was exceptionally good at blocking interferon, which is the immune system’s first responder that blocks virus protein synthesis. This is like a SIM card hack to get around sms-based 2FA or something.
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If this first line fails, second line defense kicks in, immune cells and antibodies. Blood flow increases to infected cells, nearby cells are killed to prevent spread... this is inflammation. Like a control burn around a forest fire I guess?
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The immune cells released cytokines to do this stuff. If this response is overzealous you get a cytokine storm, which seemed present in 1918 based in reports. Replicated in lab rats after the sequencing.
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Note that we’re already into the story past the point GWB got missionary about this stuff in 2004 or so. In 2011 they figured out that the virus mutated slightly by the second wave to adapt better to humans, which is why it was deadlier. Could happen with SARS-Cov2 as well.
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Btw it seems like H1N1 identifies a class of viruses based on H-N topology. Not a specific strain. I guess the genus/species type Linnean binomial nomenclatureisctoo coarse for viruses.
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So the mutation was possibly favored by wartime conditions on the western front. Normally viruses get more moderate to spread better but if everybody is dying faster from bullets, the more aggressive strains might be favored. Also mustard gas is mutagenic so might have nudged it.
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So if there’s a second winter wave if Covid and there’s a civil war after the election, we have a mutated worse strain to look forward to. Yay. This story just gets relentlessly gloomier as a precedent for 2020.
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More detective work. Drift rates in the virus suggest the North American origin story is most likely. Research by Michael Worobey of U. Arizona in 2014 showed 7 of 8 1918 H1N1 genes resembled flu genes found in North American birds.
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This is fascinating. Apparently horses rather than birds used to be the main flu reservoir. There’s a chance mechanization/cars and the retreat of horses from human life made birds the reservoir. Very circumstantial evidence but I like the story.
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There is some tricky inside baseball here about 8th gene and the W shaped mortality curve. I’m not going to try and follow the intricacies here. But the level of detail that detective work uncovers is astounding. I didn’t know flu research was so broad deep. Good work Science!™
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2 more flu epidemics in 20th century, 1957 Asian flu H2N2 and 1968 Hong Kong flu, H3N2, both share a lot of genes with H1N1. Apparently humans gave the flu to pigs, not the other way around. Swine flu should be called long pig flu.
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We stop here for tonight and reflect on the grim fact that coronaviruses are not flu viruses so a lot of this does not apply. But we have a sense of the learning curve involved.
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Chapter 15: the human factor. Apparently there was a lot of variation in who died across age and time. Age mortality had a W shape with a peak for adults and also very young and very old, already covered in previous chapter... complicated. Now geographic.
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Asia and Africa had the highest death rates. Some areas 30x the west. Persia seems to have had the highest rate at 22%. Undivided India highest absolute numbers, 13-18m at 6% fatality rate. Possibly higher than WW1. I’m guessing some of my great grandparents generation got it.
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Mostly boring survey here of patterns similar to Covid, correlated with wealth, class, caste, bring immigrants etc. Eugenicists casting aspersions at “inferior” races being weaker etc. Interestingly blanks in the US appear to have been less susceptible in 1918 unlike 2020.
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Mask wearing and banning of mass gatherings cut death tolls by up to 50% in some cities and the US was better about this than Europe. Woodrow Wilson vs Trump would be an interesting comparison. Has anyone done one?
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Mostly men died at greater rates except of course in India where these things always flip. TB was a big comorbidity. It’s weird to think about how TB was such a huge thing back then. Like diabetes today.
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It’s kinda grim that so many segments of this book are boring through no fault of the author. We’ve all learned this stuff more directly. We’re in the reboot of this movie. Well that’s it for tonight.
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Here we go again. Chapter 16, “the green shoots of recovery” Bad news: took between 1922-26 for the Spanish Flu to truly recede, basically culling the population of the weak. Sorta good news? there was a baby boom after as the healthier ones went for the demographic dividend.
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In general the world got healthier from the cull. Especially men. But babies conceived during the flu, and exposed to it prenatally were weaker, and had poorer life outcomes. Many adults who got it had chronic conditions after, just as already seen for Covid. Darwinian
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