# Spanish Flu

**URL:** <https://boards.straightdope.com/t/spanish-flu/992503>\
**Category:** Factual Questions\
**Created:** [November 2, 2023, 9:17pm UTC](https://boards.straightdope.com/t/spanish-flu/992503 "2023-11-02T21:17:49Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![EnolaStraight](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@EnolaStraight](https://boards.straightdope.com/u/EnolaStraight)\
**Post date:** [November 2, 2023, 9:17pm UTC](https://boards.straightdope.com/t/spanish-flu/992503/1 "2023-11-02T21:17:49Z")

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Does the Center for Disease Control have samples of the Spanish Flu in storage?

Did anyone think to preserve samples a century ago _just in case_ some future researcher could use it to prevent an outbreak of similarly virulent strains?

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**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\
**Post date:** [November 2, 2023, 9:25pm UTC](https://boards.straightdope.com/t/spanish-flu/992503/2 "2023-11-02T21:25:01Z")

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Well, there have already been 2 subsequent outbreaks of the same virus [Spanish flu](https://en.wikipedia.org/wiki/Spanish_flu)

> The 1918 Spanish flu was the first of three flu pandemics caused by [H1N1 influenza A virus](https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H1N1); the most recent one was the [2009 swine flu pandemic](https://en.wikipedia.org/wiki/2009_swine_flu_pandemic).[[16]](https://en.wikipedia.org/wiki/Spanish_flu#cite_note-World_Health_Organization-1999-16)[[17]](https://en.wikipedia.org/wiki/Spanish_flu#cite_note-17) The [1977 Russian flu](https://en.wikipedia.org/wiki/1977_Russian_flu) was also caused by H1N1 virus.[[16]](https://en.wikipedia.org/wiki/Spanish_flu#cite_note-World_Health_Organization-1999-16)[[18]](https://en.wikipedia.org/wiki/Spanish_flu#cite_note-18)

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**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\
**Post date:** [November 2, 2023, 9:26pm UTC](https://boards.straightdope.com/t/spanish-flu/992503/3 "2023-11-02T21:26:38Z")

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> [@EnolaStraight](#):
>
> Did anyone think to preserve samples a century ago _just in case_ some future researcher could use it to prevent an outbreak of similarly virulent strains?

It’s just H1N1 influenza.

[ninjaed]

ETA: for which we already have vaccines.

[https://www.cdc.gov/h1n1flu/vaccination/public/vaccination\_qa\_pub.htm](https://www.cdc.gov/h1n1flu/vaccination/public/vaccination_qa_pub.htm)

A new H1N1 outbreak would likely be somewhat different, and we might need to develop a new vaccine optimized to the new strain. But we know how to do that, and samples of the 1918 strain wouldn’t be necessary or helpful with that.

> **[How Influenza (Flu) Vaccines Are Made | CDC](https://www.cdc.gov/flu/prevent/how-fluvaccine-made.htm)**
>
> How Influenza (Flu) Vaccines Are Made - CDC

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**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\
**Post date:** [November 2, 2023, 9:36pm UTC](https://boards.straightdope.com/t/spanish-flu/992503/4 "2023-11-02T21:36:22Z")

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But to answer your question, it seems we have it.

HA gene:

> **[Origin and evolution of the 1918 “Spanish” influenza virus
 hemagglutinin gene](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC15547/)**
>
> The “Spanish” influenza pandemic killed over 20 million
> people in 1918 and 1919, making it the worst infectious pandemic in
> history. Here, we report the complete sequence of the hemagglutinin
> (HA) gene of the 1918 virus. Influenza RNA ...

Full sequence:

> **[High-throughput RNA sequencing of a formalin-fixed, paraffin-embedded autopsy...](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3731037/)**
>
> Most biopsy and autopsy tissues are formalin-fixed and paraffin-embedded (FFPE), but this process leads to RNA degradation that limits gene expression analysis. The RNA genome of the 1918 pandemic influenza virus was previously determined in a 9-year...

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**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\
**Post date:** [November 2, 2023, 9:40pm UTC](https://boards.straightdope.com/t/spanish-flu/992503/5 "2023-11-02T21:40:04Z")

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And with that, a thousand conspiracy theories are launched…

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**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\
**Post date:** [November 2, 2023, 9:57pm UTC](https://boards.straightdope.com/t/spanish-flu/992503/6 "2023-11-02T21:57:39Z")

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> [@EnolaStraight](#):
>
> Did anyone think to preserve samples a century ago _just in case_ some future researcher could use it to prevent an outbreak of similarly virulent strains?

In the early 1920s virology was still in its infancy and there was no way to identify individual strains or variants. Virions weren’t even imaged until 1931, and details of the protein and ribonuclaic structure of the tobacco mosaic virus (one of if not the larest virus discovered) wasn’t available until 1955 via X-ray crystallography by Rosalind Franklin. Virions tend to break down in the normal perservatives of the day, and really the only way to store virions intact for long periods is at very cold temperatures. Most archeovirology (yes, it’s a real field) is done by a combination of reconstruction of partial viral sequences and statistical methods from known viral descendants.

A new H1N1 virus with enhanced virulence over currently circulating strains is a real possibility and was considered the most likely candidate (along with H5N1 and zoonotic jump of H17N10 or H18N11) for a viral pandemic prior to SARS-CoV(-1). However, it would likely have a different structure than the strain responsible for the 1918-1920 ‘Spanish Flu’.

Stranger

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**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\
**Post date:** [November 2, 2023, 10:02pm UTC](https://boards.straightdope.com/t/spanish-flu/992503/7 "2023-11-02T22:02:21Z")

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> [@Stranger\_On\_A\_Train](#):
>
> In the early 1920s virology was still in its infancy and there was no way to identify individual strains or variants. Virions weren’t even imaged until 1931, and details of the protein and ribonuclaic structure of the tobacco mosaic virus (one of if not the larest virus discovered) wasn’t available until 1955 via X-ray crystallography by Rosalind Franklin. Virions tend to break down in the normal perservatives of the day, and really the only way to store virions intact for long periods is at very cold temperatures. Most archeovirology (yes, it’s a real field) is done by a combination of reconstruction of partial viral sequences and statistical methods from known viral descendants.

If you check the link I posted you’ll see that we have the full sequence from a formalin-fixed tissue sample.

Not the same as a viable infectious sample of the virus, of course, although if someone were determined to recreate it for some reason they could probably do it.

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**Author:** ![Banksiaman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/banksiaman/32/3334_2.png) [@Banksiaman](https://boards.straightdope.com/u/Banksiaman)\
**Post date:** [November 3, 2023, 7:40am UTC](https://boards.straightdope.com/t/spanish-flu/992503/8 "2023-11-03T07:40:53Z")

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> [@Riemann](#):
>
> If you check the link I posted you’ll see that we have the full sequence from a formalin-fixed tissue sample.

There was a 1951 expedition to Alaska to exhume bodies of people who had died in 1918-19 from influenza, and who were hoped to have been buried in permafrost-like conditions. Very well summarised by [one of the references](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2391305/) cited in the paper upstream. Unfortunately they could not isolate any influenza viral material.

The ‘formalin fixed tissue samples’ were retained in tissue banks from 1918-19 autopsies, but there was a second attempt after that to go back to Alaska to dig up frozen tissue, which was successful in showing influenza.
