tiny fixes
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Nicky Case
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README.md
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README.md
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# How To Translate
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**NOTE: I'm still editing some stuff! Words will be finalized-ish on May 4th.
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You can start on stuff below, then check for new commits on the 4th to see what else to
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translate. You're wonderful, thank you! 💖**
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**NOTE 2: Sorry these instructions are really sloppy. Am writing this at midnight, rushing
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to publish this.**
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**NOTE 3: Indie gamedev is horrible.**
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Step 1)
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Check to see if it's already been translated to your language!
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@ -29,7 +20,7 @@ Translate `words.md`, (6000 words) then export it to html
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– make sure your Markdown app supports footnotes –
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and copy-paste that into the `<article></article>` part of `index.html`.
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Translate the `<head>`, sidebars, & footer of `index.html` (200 words)
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Translate the `<head>`, sidebars, & footer of `index.html` (200 words) **Feel free to add yourself in the header/footer credits as a translator! :)**
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Translate the images in `/pics` (800 words)
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If you don't have image-editing software, ask for help on the Github Issue!
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102
index.html
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index.html
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<!-- - - - - - - - - - - - - - - - - - - - - - - -->
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<div id="translations">
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Translations!
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<ul>
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<li><a href='https://ncase.me/covid-19/'>English</a></li>
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<li><a href='https://eed3si9n.github.io/covid-19/'>日本語</a></li>
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</ul>
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@ -49,7 +49,7 @@
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<div id="sharing">
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Help this guide
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get R > 1:
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get its R > 1:
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<br>
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<span id='share_title'>
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What Happens Next? COVID-19 Futures, Explained With Playable Simulations
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@ -228,7 +228,7 @@
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<iframe src="sim?stage=epi-6a&format=calc" width="285" height="255"></iframe>
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</div>
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<p>But remember, the fewer <span class="nowrap"><icon s></icon>s</span> there are, the <em>slower</em> <span class="nowrap"><icon s></icon>s</span> become <span class="nowrap"><icon i>s.</icon></span> The <em>current</em> reproduction number (R) depends not just on the <em>basic</em> reproduction number (R<sub>0</sub>), but <em>also</em> on how many people are no longer <icon s></icon> Susceptible. (For example, by recovering & getting natural immunity.)</p>
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<p>But remember, the fewer <span class="nowrap"><icon s></icon>s</span> there are, the <em>slower</em> <span class="nowrap"><icon s></icon>s</span> become <span class="nowrap"><icon i></icon>s.</span> The <em>current</em> reproduction number (R) depends not just on the <em>basic</em> reproduction number (R<sub>0</sub>), but <em>also</em> on how many people are no longer <icon s></icon> Susceptible. (For example, by recovering & getting natural immunity.)</p>
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<div class="sim">
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<iframe src="sim?stage=epi-6b&format=calc" width="285" height="390"></iframe>
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@ -406,15 +406,15 @@
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<p><img src="pics/dp3t.png" alt=""></p>
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<p>(& <a href="https://ncase.me/contact-tracing/">here's the full comic</a>)</p>
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<p>(<a href="https://ncase.me/contact-tracing/">Here's the full comic</a>. Details about "pranking"/false positives/etc in footnote:<sup id="fnref24"><a href="#fn24" rel="footnote">24</a></sup>)</p>
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<p>Along with similar teams like TCN Protocol<sup id="fnref24"><a href="#fn24" rel="footnote">24</a></sup> and MIT PACT<sup id="fnref25"><a href="#fn25" rel="footnote">25</a></sup>, they've inspired Apple & Google to bake privacy-first contact tracing directly into Android/iOS.<sup id="fnref26"><a href="#fn26" rel="footnote">26</a></sup> (Don't trust Google/Apple? Good! The beauty of this system is it doesn't <em>need</em> trust!) Soon, your local public health agency may ask you to download an app. If it's privacy-first with publicly-available code, please do!</p>
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<p>Along with similar teams like TCN Protocol<sup id="fnref25"><a href="#fn25" rel="footnote">25</a></sup> and MIT PACT<sup id="fnref26"><a href="#fn26" rel="footnote">26</a></sup>, they've inspired Apple & Google to bake privacy-first contact tracing directly into Android/iOS.<sup id="fnref27"><a href="#fn27" rel="footnote">27</a></sup> (Don't trust Google/Apple? Good! The beauty of this system is it doesn't <em>need</em> trust!) Soon, your local public health agency may ask you to download an app. If it's privacy-first with publicly-available code, please do!</p>
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<p>But what about folks without smartphones? Or infections through doorknobs? Or "true" asymptomatic cases? Contact tracing apps can't catch all transmissions... <em>and that's okay!</em> We don't need to catch <em>all</em> transmissions, just 60%+ to get R < 1.</p>
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<p>(Rant about the confusion about pre-symptomatic vs "true" asymptomatic. "True" asymptomatics are rare:<sup id="fnref27"><a href="#fn27" rel="footnote">27</a></sup>)</p>
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<p>(Footnote rant about the confusion between pre-symptomatic vs "true" asymptomatic – "true" asymptomatics are rare:<sup id="fnref28"><a href="#fn28" rel="footnote">28</a></sup>)</p>
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<p>Isolating <em>symptomatic</em> cases would reduce R by up to 40%, and quarantining their <em>pre/a-symptomatic</em> contacts would reduce R by up to 50%<sup id="fnref28"><a href="#fn28" rel="footnote">28</a></sup>:</p>
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<p>Isolating <em>symptomatic</em> cases would reduce R by up to 40%, and quarantining their <em>pre/a-symptomatic</em> contacts would reduce R by up to 50%<sup id="fnref29"><a href="#fn29" rel="footnote">29</a></sup>:</p>
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<div class="sim">
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<iframe src="sim?stage=int-4a&format=calc" width="285" height="340"></iframe>
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@ -463,17 +463,17 @@
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<p><em>"Wait,"</em> you might ask, <em>"I thought face masks don't stop you from getting sick?"</em></p>
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<p>You're right. Masks don't stop you from getting sick<sup id="fnref29"><a href="#fn29" rel="footnote">29</a></sup>... they stop you from getting <em>others</em> sick.</p>
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<p>You're right. Masks don't stop you from getting sick<sup id="fnref30"><a href="#fn30" rel="footnote">30</a></sup>... they stop you from getting <em>others</em> sick.</p>
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<p><img src="pics/masks.png" alt=""></p>
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<p>To put a number on it: surgical masks <em>on the sick person</em> reduce cold & flu viruses in aerosols by 70%.<sup id="fnref30"><a href="#fn30" rel="footnote">30</a></sup> Reducing transmissions by 70% would be as large an impact as a lockdown!</p>
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<p>To put a number on it: surgical masks <em>on the sick person</em> reduce cold & flu viruses in aerosols by 70%.<sup id="fnref31"><a href="#fn31" rel="footnote">31</a></sup> Reducing transmissions by 70% would be as large an impact as a lockdown!</p>
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<p>However, we don't know for sure the impact of masks on COVID-19 <em>specifically</em>. In science, one should only publish a finding if you're 95% sure of it. (...should.<sup id="fnref31"><a href="#fn31" rel="footnote">31</a></sup>) Masks, as of May 1st 2020, are less than "95% sure".</p>
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<p>However, we don't know for sure the impact of masks on COVID-19 <em>specifically</em>. In science, one should only publish a finding if you're 95% sure of it. (...should.<sup id="fnref32"><a href="#fn32" rel="footnote">32</a></sup>) Masks, as of May 1st 2020, are less than "95% sure".</p>
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<p>However, pandemics are like poker. <strong>Make bets only when you're 95% sure, and you'll lose everything at stake.</strong> As a recent article on masks in the British Medical Journal notes,<sup id="fnref32"><a href="#fn32" rel="footnote">32</a></sup> we <em>have</em> to make cost/benefit analyses under uncertainty. Like so:</p>
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<p>However, pandemics are like poker. <strong>Make bets only when you're 95% sure, and you'll lose everything at stake.</strong> As a recent article on masks in the British Medical Journal notes,<sup id="fnref33"><a href="#fn33" rel="footnote">33</a></sup> we <em>have</em> to make cost/benefit analyses under uncertainty. Like so:</p>
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<p>Cost: If homemade cloth masks (which are ~2/3 as effective as surgical masks<sup id="fnref33"><a href="#fn33" rel="footnote">33</a></sup>), super cheap. If surgical masks, more expensive but still pretty cheap.</p>
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<p>Cost: If homemade cloth masks (which are ~2/3 as effective as surgical masks<sup id="fnref34"><a href="#fn34" rel="footnote">34</a></sup>), super cheap. If surgical masks, more expensive but still pretty cheap.</p>
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<p>Benefit: Even if it's a 50–50 chance of surgical masks reducing transmission by 0% or 70%, the average "expected value" is still 35%, same as a half-lockdown! So let's guess-timate that surgical masks reduce R by up to 35%, discounted for our uncertainty. (Again, you can challenge our assumptions by turning the sliders up/down)</p>
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@ -481,7 +481,7 @@
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<iframe src="sim?stage=int-6a&format=calc" width="285" height="380"></iframe>
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</div>
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<p>(other arguments for/against masks:<sup id="fnref34"><a href="#fn34" rel="footnote">34</a></sup>)</p>
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<p>(other arguments for/against masks:<sup id="fnref35"><a href="#fn35" rel="footnote">35</a></sup>)</p>
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<p>Masks <em>alone</em> won't get R < 1. But if handwashing & "Test, Trace, Isolate" only gets us to R = 1.10, having just 1/3 of people wear masks would tip that over to R < 1, virus contained!</p>
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<p>Okay, this isn't an "intervention" we can control, but it will help! Some news outlets report that summer won't do anything to COVID-19. They're half right: summer won't get R < 1, but it <em>will</em> reduce R.</p>
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<p>For COVID-19, every extra 1° Celsius (2.2° Fahrenheit) makes R drop by 1.2%.<sup id="fnref35"><a href="#fn35" rel="footnote">35</a></sup> The summer-winter difference in New York City is 15°C (60°F), so summer will make R drop by 18%.</p>
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<p>For COVID-19, every extra 1° Celsius (2.2° Fahrenheit) makes R drop by 1.2%.<sup id="fnref36"><a href="#fn36" rel="footnote">36</a></sup> The summer-winter difference in New York City is 15°C (60°F), so summer will make R drop by 18%.</p>
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<div class="sim">
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<iframe src="sim?stage=int-6b&format=calc" width="285" height="220"></iframe>
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<p>...<em>for how long?</em></p>
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<ul>
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<li>COVID-19 is most closely related to SARS, which gave its survivors 2 years of immunity.<sup id="fnref36"><a href="#fn36" rel="footnote">36</a></sup></li>
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<li>The coronaviruses that cause "the" common cold give you 8 months of immunity.<sup id="fnref37"><a href="#fn37" rel="footnote">37</a></sup></li>
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<li>There's reports of folks recovering from COVID-19, then testing positive again, but it's unclear if these are false positives.<sup id="fnref38"><a href="#fn38" rel="footnote">38</a></sup></li>
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<li>One <em>not-yet-peer-reviewed</em> study on monkeys showed immunity to the COVID-19 coronavirus for at least 28 days.<sup id="fnref39"><a href="#fn39" rel="footnote">39</a></sup></li>
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<li>COVID-19 is most closely related to SARS, which gave its survivors 2 years of immunity.<sup id="fnref37"><a href="#fn37" rel="footnote">37</a></sup></li>
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<li>The coronaviruses that cause "the" common cold give you 8 months of immunity.<sup id="fnref38"><a href="#fn38" rel="footnote">38</a></sup></li>
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<li>There's reports of folks recovering from COVID-19, then testing positive again, but it's unclear if these are false positives.<sup id="fnref39"><a href="#fn39" rel="footnote">39</a></sup></li>
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<li>One <em>not-yet-peer-reviewed</em> study on monkeys showed immunity to the COVID-19 coronavirus for at least 28 days.<sup id="fnref40"><a href="#fn40" rel="footnote">40</a></sup></li>
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</ul>
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<p>But for COVID-19 <em>in humans</em>, as of May 1st 2020, "how long" is the big unknown.</p>
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<p><strong>To be clear: this is unlikely.</strong> Most epidemiologists expect a vaccine in 1 to 2 years. Sure, there's never been a vaccine for any of the other coronaviruses before, but that's because SARS was eradicated quickly, and "the" common cold wasn't worth the investment. </p>
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<p>Still, infectious disease researchers have expressed worries: What if we can't make enough?<sup id="fnref40"><a href="#fn40" rel="footnote">40</a></sup> What if we rush it, and it's not safe?<sup id="fnref41"><a href="#fn41" rel="footnote">41</a></sup></p>
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<p>Still, infectious disease researchers have expressed worries: What if we can't make enough?<sup id="fnref41"><a href="#fn41" rel="footnote">41</a></sup> What if we rush it, and it's not safe?<sup id="fnref42"><a href="#fn42" rel="footnote">42</a></sup></p>
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<p>Even in the nightmare "no-vaccine" scenario, we still have 3 ways out. From most to least terrible:</p>
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</div>
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</div>
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<p>Plane's sunk. We've scrambled onto the life rafts. It's time to find dry land.<sup id="fnref42"><a href="#fn42" rel="footnote">42</a></sup></p>
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<p>Plane's sunk. We've scrambled onto the life rafts. It's time to find dry land.<sup id="fnref43"><a href="#fn43" rel="footnote">43</a></sup></p>
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<p>Teams of epidemiologists and policymakers (<a href="https://www.americanprogress.org/issues/healthcare/news/2020/04/03/482613/national-state-plan-end-coronavirus-crisis/">left</a>, <a href="https://www.aei.org/research-products/report/national-coronavirus-response-a-road-map-to-reopening/">right</a>, and <a href="https://ethics.harvard.edu/covid-roadmap">multi-partisan</a>) have come to a consensus on how to beat COVID-19, while protecting our lives <em>and</em> liberties.</p>
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</li>
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<li id="fn24">
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<p><a href="https://github.com/TCNCoalition/TCN#tcn-protocol">Temporary Contact Numbers, a decentralized, privacy-first contact tracing protocol</a> <a href="#fnref24" rev="footnote">↩</a></p>
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<p>To prevent "pranking" (people falsely claiming to be infected), the DP-3T Protocol requires that the hospital first give you a One-Time Passcode that lets you upload your messages. <a href="#fnref24" rev="footnote">↩</a></p>
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<p>False positives are a problem in both manual & digital contact tracing. Still, we can reduce false positives in 2 ways: 1) By notifying Bobs only if they heard, say, 30+ min worth of messages, not just one message in passing. And 2) If the app <em>does</em> think Bob's been exposed, it can refer Bob to a <em>manual</em> contact tracer, for an in-depth follow-up interview.</p>
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<p>For other issues like data bandwidth, source integrity, and other security issues, check out <a href="https://github.com/DP-3T/documents#decentralized-privacy-preserving-proximity-tracing">the open-source DP-3T whitepapers!</a></p>
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</li>
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<li id="fn25">
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<p><a href="https://pact.mit.edu/">PACT: Private Automated Contact Tracing</a> <a href="#fnref25" rev="footnote">↩</a></p>
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<p><a href="https://github.com/TCNCoalition/TCN#tcn-protocol">Temporary Contact Numbers, a decentralized, privacy-first contact tracing protocol</a> <a href="#fnref25" rev="footnote">↩</a></p>
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</li>
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<li id="fn26">
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<p><a href="https://www.apple.com/ca/newsroom/2020/04/apple-and-google-partner-on-covid-19-contact-tracing-technology/">Apple and Google partner on COVID-19 contact tracing technology </a>. Note they're not making the apps <em>themselves</em>, just creating the systems that will <em>support</em> those apps. <a href="#fnref26" rev="footnote">↩</a></p>
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<p><a href="https://pact.mit.edu/">PACT: Private Automated Contact Tracing</a> <a href="#fnref26" rev="footnote">↩</a></p>
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</li>
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<li id="fn27">
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<p>Lots of news reports – and honestly, many research papers – did not distinguish between "cases who showed no symptoms when we tested them" (pre-symptomatic) and "cases who showed no symptoms <em>ever</em>" (true asymptomatic). The only way you could tell the difference is by following up with cases later. <a href="#fnref27" rev="footnote">↩</a></p>
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<p><a href="https://www.apple.com/ca/newsroom/2020/04/apple-and-google-partner-on-covid-19-contact-tracing-technology/">Apple and Google partner on COVID-19 contact tracing technology </a>. Note they're not making the apps <em>themselves</em>, just creating the systems that will <em>support</em> those apps. <a href="#fnref27" rev="footnote">↩</a></p>
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</li>
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<li id="fn28">
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<p>Lots of news reports – and honestly, many research papers – did not distinguish between "cases who showed no symptoms when we tested them" (pre-symptomatic) and "cases who showed no symptoms <em>ever</em>" (true asymptomatic). The only way you could tell the difference is by following up with cases later. <a href="#fnref28" rev="footnote">↩</a></p>
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<p>Which is what <a href="https://wwwnc.cdc.gov/eid/article/26/8/20-1274_article">this study</a> did. (Disclaimer: "Early release articles are not considered as final versions.") In a call center in South Korea that had a COVID-19 outbreak, "only 4 (1.9%) remained asymptomatic within 14 days of quarantine, and none of their household contacts acquired secondary infections."</p>
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<p>So that means "true asymptomatics" are rare, and catching the disease from a true asymptomatic may be even rarer!</p>
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</li>
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<li id="fn28">
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<p>From the same Oxford study that first recommended apps to fight COVID-19: <a href="https://science.sciencemag.org/content/early/2020/04/09/science.abb6936/tab-figures-data">Luca Ferretti & Chris Wymant et al</a> See Figure 2. Assuming R<sub>0</sub> = 2.0, they found that: <a href="#fnref28" rev="footnote">↩</a></p>
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<li id="fn29">
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<p>From the same Oxford study that first recommended apps to fight COVID-19: <a href="https://science.sciencemag.org/content/early/2020/04/09/science.abb6936/tab-figures-data">Luca Ferretti & Chris Wymant et al</a> See Figure 2. Assuming R<sub>0</sub> = 2.0, they found that: <a href="#fnref29" rev="footnote">↩</a></p>
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<ul>
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<li>Symptomatics contribute R = 0.8 (40%)</li>
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<p>And add up the pre- & a-symptomatic contacts (45% + 5%) and you get 50% of R!</p>
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</li>
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<li id="fn29">
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<p>“None of these surgical masks exhibited adequate filter performance and facial fit characteristics to be considered respiratory protection devices.” <a href="https://www.sciencedirect.com/science/article/pii/S0196655307007742">Tara Oberg & Lisa M. Brosseau</a> <a href="#fnref29" rev="footnote">↩</a></p>
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</li>
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<li id="fn30">
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<p>“The overall 3.4 fold reduction [70% reduction] in aerosol copy numbers we observed combined with a nearly complete elimination of large droplet spray demonstrated by Johnson et al. suggests that surgical masks worn by infected persons could have a clinically significant impact on transmission.” <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3591312/">Milton DK, Fabian MP, Cowling BJ, Grantham ML, McDevitt JJ</a> <a href="#fnref30" rev="footnote">↩</a></p>
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<p>“None of these surgical masks exhibited adequate filter performance and facial fit characteristics to be considered respiratory protection devices.” <a href="https://www.sciencedirect.com/science/article/pii/S0196655307007742">Tara Oberg & Lisa M. Brosseau</a> <a href="#fnref30" rev="footnote">↩</a></p>
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</li>
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<li id="fn31">
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<p>Any actual scientist who read that last sentence is probably laugh-crying right now. See: <a href="https://en.wikipedia.org/wiki/Data_dredging">p-hacking</a>, <a href="https://en.wikipedia.org/wiki/Replication_crisis">the replication crisis</a>) <a href="#fnref31" rev="footnote">↩</a></p>
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<p>“The overall 3.4 fold reduction [70% reduction] in aerosol copy numbers we observed combined with a nearly complete elimination of large droplet spray demonstrated by Johnson et al. suggests that surgical masks worn by infected persons could have a clinically significant impact on transmission.” <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3591312/">Milton DK, Fabian MP, Cowling BJ, Grantham ML, McDevitt JJ</a> <a href="#fnref31" rev="footnote">↩</a></p>
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</li>
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<li id="fn32">
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<p>“It is time to apply the precautionary principle” <a href="https://www.bmj.com/content/bmj/369/bmj.m1435.full.pdf">Trisha Greenhalgh et al [PDF]</a> <a href="#fnref32" rev="footnote">↩</a></p>
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<p>Any actual scientist who read that last sentence is probably laugh-crying right now. See: <a href="https://en.wikipedia.org/wiki/Data_dredging">p-hacking</a>, <a href="https://en.wikipedia.org/wiki/Replication_crisis">the replication crisis</a>) <a href="#fnref32" rev="footnote">↩</a></p>
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</li>
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<li id="fn33">
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<p><a href="https://www.cambridge.org/core/journals/disaster-medicine-and-public-health-preparedness/article/testing-the-efficacy-of-homemade-masks-would-they-protect-in-an-influenza-pandemic/0921A05A69A9419C862FA2F35F819D55">Davies, A., Thompson, K., Giri, K., Kafatos, G., Walker, J., & Bennett, A</a> See Table 1: a 100% cotton T-shirt has around 2/3 the filtration efficiency as a surgical mask, for the two bacterial aerosols they tested. <a href="#fnref33" rev="footnote">↩</a></p>
|
||||
<p>“It is time to apply the precautionary principle” <a href="https://www.bmj.com/content/bmj/369/bmj.m1435.full.pdf">Trisha Greenhalgh et al [PDF]</a> <a href="#fnref33" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn34">
|
||||
<p><strong>"We need to save supplies for hospitals."</strong> <em>Absolutely agreed.</em> But that's more of an argument for increasing mask production, not rationing. In the meantime, we can make cloth masks. <a href="#fnref34" rev="footnote">↩</a></p>
|
||||
<p><a href="https://www.cambridge.org/core/journals/disaster-medicine-and-public-health-preparedness/article/testing-the-efficacy-of-homemade-masks-would-they-protect-in-an-influenza-pandemic/0921A05A69A9419C862FA2F35F819D55">Davies, A., Thompson, K., Giri, K., Kafatos, G., Walker, J., & Bennett, A</a> See Table 1: a 100% cotton T-shirt has around 2/3 the filtration efficiency as a surgical mask, for the two bacterial aerosols they tested. <a href="#fnref34" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn35">
|
||||
<p><strong>"We need to save supplies for hospitals."</strong> <em>Absolutely agreed.</em> But that's more of an argument for increasing mask production, not rationing. In the meantime, we can make cloth masks. <a href="#fnref35" rev="footnote">↩</a></p>
|
||||
|
||||
<p><strong>"They're hard to wear correctly."</strong> It's also hard to wash your hands according to the WHO Guidelines – seriously, "Step 3) right palm over left dorsum"?! – but we still recommend handwashing, because imperfect is still better than nothing.</p>
|
||||
|
||||
<p><strong>"It'll make people more reckless with handwashing & social distancing."</strong> Sure, and safety belts make people ignore stop signs, and flossing makes people eat rocks. But seriously, we'd argue the opposite: masks are a <em>constant physical reminder</em> to be careful – and in East Asia, masks are also a symbol of solidarity!</p>
|
||||
</li>
|
||||
|
||||
<li id="fn35">
|
||||
<p>“One-degree Celsius increase in temperature [...] lower[s] R by 0.0225” and “The average R-value of these 100 cities is 1.83”. 0.0225 ÷ 1.83 = ~1.2%. <a href="https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3551767">Wang, Jingyuan and Tang, Ke and Feng, Kai and Lv, Weifeng</a> <a href="#fnref35" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn36">
|
||||
<p>“SARS-specific antibodies were maintained for an average of 2 years [...] Thus, SARS patients might be susceptible to reinfection ≥3 years after initial exposure.” <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/">Wu LP, Wang NC, Chang YH, et al.</a> "Sadly" we'll never know how long SARS immunity would have really lasted, since we eradicated it so quickly. <a href="#fnref36" rev="footnote">↩</a></p>
|
||||
<p>“One-degree Celsius increase in temperature [...] lower[s] R by 0.0225” and “The average R-value of these 100 cities is 1.83”. 0.0225 ÷ 1.83 = ~1.2%. <a href="https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3551767">Wang, Jingyuan and Tang, Ke and Feng, Kai and Lv, Weifeng</a> <a href="#fnref36" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn37">
|
||||
<p>“We found no significant difference between the probability of testing positive at least once and the probability of a recurrence for the beta-coronaviruses HKU1 and OC43 at 34 weeks after enrollment/first infection.” <a href="http://www.columbia.edu/%7Ejls106/galanti_shaman_ms_supp.pdf">Marta Galanti & Jeffrey Shaman (PDF)</a> <a href="#fnref37" rev="footnote">↩</a></p>
|
||||
<p>“SARS-specific antibodies were maintained for an average of 2 years [...] Thus, SARS patients might be susceptible to reinfection ≥3 years after initial exposure.” <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/">Wu LP, Wang NC, Chang YH, et al.</a> "Sadly" we'll never know how long SARS immunity would have really lasted, since we eradicated it so quickly. <a href="#fnref37" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn38">
|
||||
<p>“Once a person fights off a virus, viral particles tend to linger for some time. These cannot cause infections, but they can trigger a positive test.” <a href="https://www.statnews.com/2020/04/20/everything-we-know-about-coronavirus-immunity-and-antibodies-and-plenty-we-still-dont/">from STAT News by Andrew Joseph</a> <a href="#fnref38" rev="footnote">↩</a></p>
|
||||
<p>“We found no significant difference between the probability of testing positive at least once and the probability of a recurrence for the beta-coronaviruses HKU1 and OC43 at 34 weeks after enrollment/first infection.” <a href="http://www.columbia.edu/%7Ejls106/galanti_shaman_ms_supp.pdf">Marta Galanti & Jeffrey Shaman (PDF)</a> <a href="#fnref38" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn39">
|
||||
<p>From <a href="https://www.biorxiv.org/content/10.1101/2020.03.13.990226v1.abstract">Bao et al.</a> <em>Disclaimer: This article is a preprint and has not been certified by peer review (yet).</em> Also, to emphasize: they only tested re-infection 28 days later. <a href="#fnref39" rev="footnote">↩</a></p>
|
||||
<p>“Once a person fights off a virus, viral particles tend to linger for some time. These cannot cause infections, but they can trigger a positive test.” <a href="https://www.statnews.com/2020/04/20/everything-we-know-about-coronavirus-immunity-and-antibodies-and-plenty-we-still-dont/">from STAT News by Andrew Joseph</a> <a href="#fnref39" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn40">
|
||||
<p>“If a coronavirus vaccine arrives, can the world make enough?” <a href="https://www.nature.com/articles/d41586-020-01063-8">by Roxanne Khamsi, on Nature</a> <a href="#fnref40" rev="footnote">↩</a></p>
|
||||
<p>From <a href="https://www.biorxiv.org/content/10.1101/2020.03.13.990226v1.abstract">Bao et al.</a> <em>Disclaimer: This article is a preprint and has not been certified by peer review (yet).</em> Also, to emphasize: they only tested re-infection 28 days later. <a href="#fnref40" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn41">
|
||||
<p>“Don’t rush to deploy COVID-19 vaccines and drugs without sufficient safety guarantees” <a href="https://www.nature.com/articles/d41586-020-00751-9">by Shibo Jiang, on Nature</a> <a href="#fnref41" rev="footnote">↩</a></p>
|
||||
<p>“If a coronavirus vaccine arrives, can the world make enough?” <a href="https://www.nature.com/articles/d41586-020-01063-8">by Roxanne Khamsi, on Nature</a> <a href="#fnref41" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn42">
|
||||
<p>Dry land metaphor <a href="https://www.statnews.com/2020/04/01/navigating-covid-19-pandemic/">from Marc Lipsitch & Yonatan Grad, on STAT News</a> <a href="#fnref42" rev="footnote">↩</a></p>
|
||||
<p>“Don’t rush to deploy COVID-19 vaccines and drugs without sufficient safety guarantees” <a href="https://www.nature.com/articles/d41586-020-00751-9">by Shibo Jiang, on Nature</a> <a href="#fnref42" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn43">
|
||||
<p>Dry land metaphor <a href="https://www.statnews.com/2020/04/01/navigating-covid-19-pandemic/">from Marc Lipsitch & Yonatan Grad, on STAT News</a> <a href="#fnref43" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
</ol>
|
||||
|
|
@ -887,7 +895,7 @@
|
|||
|
||||
<div>
|
||||
|
||||
Help this post get R > 1: <span class='shareables in_footer' style='position: relative; top: 17px; right: -6px;'></span>
|
||||
Help this post get its R > 1: <span class='shareables in_footer' style='position: relative; top: 17px; right: -6px;'></span>
|
||||
<br><br>
|
||||
This guide is
|
||||
<br>
|
||||
|
|
|
|||
|
|
@ -96,7 +96,7 @@
|
|||
<br>
|
||||
</span>
|
||||
<span id="int_block_4">
|
||||
Summer
|
||||
Strength of Summer
|
||||
<br>
|
||||
<input class="sim_input recordable" type="range" id="p_summer" min="0" max="1" step="0.001" value="0">
|
||||
<br>
|
||||
|
|
|
|||
|
|
@ -174,7 +174,7 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
<iframe src="sim?stage=epi-6a&format=calc" width="285" height="255"></iframe>
|
||||
</div>
|
||||
|
||||
<p>But remember, the fewer <span class="nowrap"><icon s></icon>s</span> there are, the <em>slower</em> <span class="nowrap"><icon s></icon>s</span> become <span class="nowrap"><icon i>s.</icon></span> The <em>current</em> reproduction number (R) depends not just on the <em>basic</em> reproduction number (R<sub>0</sub>), but <em>also</em> on how many people are no longer <icon s></icon> Susceptible. (For example, by recovering & getting natural immunity.)</p>
|
||||
<p>But remember, the fewer <span class="nowrap"><icon s></icon>s</span> there are, the <em>slower</em> <span class="nowrap"><icon s></icon>s</span> become <span class="nowrap"><icon i></icon>s.</span> The <em>current</em> reproduction number (R) depends not just on the <em>basic</em> reproduction number (R<sub>0</sub>), but <em>also</em> on how many people are no longer <icon s></icon> Susceptible. (For example, by recovering & getting natural immunity.)</p>
|
||||
|
||||
<div class="sim">
|
||||
<iframe src="sim?stage=epi-6b&format=calc" width="285" height="390"></iframe>
|
||||
|
|
@ -338,7 +338,7 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
|
||||
<p>This is called <strong>contact tracing</strong>. It's an old idea, was used at an unprecedented scale to contain Ebola<sup id="fnref23"><a href="#fn23" rel="footnote">23</a></sup>, and now it's core part of how Taiwan & South Korea are containing COVID-19!</p>
|
||||
|
||||
<p>(It also lets us use our limited tests more efficiently, to find pre-symptomatic <icon i></icon>s without needing to test almost everyone.)</p><p>(It also lets us use our limited tests more efficiently, to find pre-symptomatic <span class="nowrap"><icon i></icon>s</span> without needing to test almost everyone.)</p>
|
||||
<p>(It also lets us use our limited tests more efficiently, to find pre-symptomatic <span class="nowrap"><icon i></icon>s</span> without needing to test almost everyone.)</p>
|
||||
|
||||
<p>Traditionally, contacts are found with in-person interviews, but those <em>alone</em> are too slow for COVID-19's ~48 hour window. That's why contact tracers need help, and be supported by – <em>NOT</em> replaced by – contact tracing apps.</p>
|
||||
|
||||
|
|
@ -352,15 +352,15 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
|
||||
<p><img src="pics/dp3t.png" alt=""></p>
|
||||
|
||||
<p>(& <a href="https://ncase.me/contact-tracing/">here's the full comic</a>)</p>
|
||||
<p>(<a href="https://ncase.me/contact-tracing/">Here's the full comic</a>. Details about "pranking"/false positives/etc in footnote:<sup id="fnref24"><a href="#fn24" rel="footnote">24</a></sup>)</p>
|
||||
|
||||
<p>Along with similar teams like TCN Protocol<sup id="fnref24"><a href="#fn24" rel="footnote">24</a></sup> and MIT PACT<sup id="fnref25"><a href="#fn25" rel="footnote">25</a></sup>, they've inspired Apple & Google to bake privacy-first contact tracing directly into Android/iOS.<sup id="fnref26"><a href="#fn26" rel="footnote">26</a></sup> (Don't trust Google/Apple? Good! The beauty of this system is it doesn't <em>need</em> trust!) Soon, your local public health agency may ask you to download an app. If it's privacy-first with publicly-available code, please do!</p>
|
||||
<p>Along with similar teams like TCN Protocol<sup id="fnref25"><a href="#fn25" rel="footnote">25</a></sup> and MIT PACT<sup id="fnref26"><a href="#fn26" rel="footnote">26</a></sup>, they've inspired Apple & Google to bake privacy-first contact tracing directly into Android/iOS.<sup id="fnref27"><a href="#fn27" rel="footnote">27</a></sup> (Don't trust Google/Apple? Good! The beauty of this system is it doesn't <em>need</em> trust!) Soon, your local public health agency may ask you to download an app. If it's privacy-first with publicly-available code, please do!</p>
|
||||
|
||||
<p>But what about folks without smartphones? Or infections through doorknobs? Or "true" asymptomatic cases? Contact tracing apps can't catch all transmissions... <em>and that's okay!</em> We don't need to catch <em>all</em> transmissions, just 60%+ to get R < 1.</p>
|
||||
|
||||
<p>(Rant about the confusion about pre-symptomatic vs "true" asymptomatic. "True" asymptomatics are rare:<sup id="fnref27"><a href="#fn27" rel="footnote">27</a></sup>)</p>
|
||||
<p>(Footnote rant about the confusion between pre-symptomatic vs "true" asymptomatic – "true" asymptomatics are rare:<sup id="fnref28"><a href="#fn28" rel="footnote">28</a></sup>)</p>
|
||||
|
||||
<p>Isolating <em>symptomatic</em> cases would reduce R by up to 40%, and quarantining their <em>pre/a-symptomatic</em> contacts would reduce R by up to 50%<sup id="fnref28"><a href="#fn28" rel="footnote">28</a></sup>:</p>
|
||||
<p>Isolating <em>symptomatic</em> cases would reduce R by up to 40%, and quarantining their <em>pre/a-symptomatic</em> contacts would reduce R by up to 50%<sup id="fnref29"><a href="#fn29" rel="footnote">29</a></sup>:</p>
|
||||
|
||||
<div class="sim">
|
||||
<iframe src="sim?stage=int-4a&format=calc" width="285" height="340"></iframe>
|
||||
|
|
@ -409,17 +409,17 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
|
||||
<p><em>"Wait,"</em> you might ask, <em>"I thought face masks don't stop you from getting sick?"</em></p>
|
||||
|
||||
<p>You're right. Masks don't stop you from getting sick<sup id="fnref29"><a href="#fn29" rel="footnote">29</a></sup>... they stop you from getting <em>others</em> sick.</p>
|
||||
<p>You're right. Masks don't stop you from getting sick<sup id="fnref30"><a href="#fn30" rel="footnote">30</a></sup>... they stop you from getting <em>others</em> sick.</p>
|
||||
|
||||
<p><img src="pics/masks.png" alt=""></p>
|
||||
|
||||
<p>To put a number on it: surgical masks <em>on the sick person</em> reduce cold & flu viruses in aerosols by 70%.<sup id="fnref30"><a href="#fn30" rel="footnote">30</a></sup> Reducing transmissions by 70% would be as large an impact as a lockdown!</p>
|
||||
<p>To put a number on it: surgical masks <em>on the sick person</em> reduce cold & flu viruses in aerosols by 70%.<sup id="fnref31"><a href="#fn31" rel="footnote">31</a></sup> Reducing transmissions by 70% would be as large an impact as a lockdown!</p>
|
||||
|
||||
<p>However, we don't know for sure the impact of masks on COVID-19 <em>specifically</em>. In science, one should only publish a finding if you're 95% sure of it. (...should.<sup id="fnref31"><a href="#fn31" rel="footnote">31</a></sup>) Masks, as of May 1st 2020, are less than "95% sure".</p>
|
||||
<p>However, we don't know for sure the impact of masks on COVID-19 <em>specifically</em>. In science, one should only publish a finding if you're 95% sure of it. (...should.<sup id="fnref32"><a href="#fn32" rel="footnote">32</a></sup>) Masks, as of May 1st 2020, are less than "95% sure".</p>
|
||||
|
||||
<p>However, pandemics are like poker. <strong>Make bets only when you're 95% sure, and you'll lose everything at stake.</strong> As a recent article on masks in the British Medical Journal notes,<sup id="fnref32"><a href="#fn32" rel="footnote">32</a></sup> we <em>have</em> to make cost/benefit analyses under uncertainty. Like so:</p>
|
||||
<p>However, pandemics are like poker. <strong>Make bets only when you're 95% sure, and you'll lose everything at stake.</strong> As a recent article on masks in the British Medical Journal notes,<sup id="fnref33"><a href="#fn33" rel="footnote">33</a></sup> we <em>have</em> to make cost/benefit analyses under uncertainty. Like so:</p>
|
||||
|
||||
<p>Cost: If homemade cloth masks (which are ~2/3 as effective as surgical masks<sup id="fnref33"><a href="#fn33" rel="footnote">33</a></sup>), super cheap. If surgical masks, more expensive but still pretty cheap.</p>
|
||||
<p>Cost: If homemade cloth masks (which are ~2/3 as effective as surgical masks<sup id="fnref34"><a href="#fn34" rel="footnote">34</a></sup>), super cheap. If surgical masks, more expensive but still pretty cheap.</p>
|
||||
|
||||
<p>Benefit: Even if it's a 50–50 chance of surgical masks reducing transmission by 0% or 70%, the average "expected value" is still 35%, same as a half-lockdown! So let's guess-timate that surgical masks reduce R by up to 35%, discounted for our uncertainty. (Again, you can challenge our assumptions by turning the sliders up/down)</p>
|
||||
|
||||
|
|
@ -427,7 +427,7 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
<iframe src="sim?stage=int-6a&format=calc" width="285" height="380"></iframe>
|
||||
</div>
|
||||
|
||||
<p>(other arguments for/against masks:<sup id="fnref34"><a href="#fn34" rel="footnote">34</a></sup>)</p>
|
||||
<p>(other arguments for/against masks:<sup id="fnref35"><a href="#fn35" rel="footnote">35</a></sup>)</p>
|
||||
|
||||
<p>Masks <em>alone</em> won't get R < 1. But if handwashing & "Test, Trace, Isolate" only gets us to R = 1.10, having just 1/3 of people wear masks would tip that over to R < 1, virus contained!</p>
|
||||
|
||||
|
|
@ -435,7 +435,7 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
|
||||
<p>Okay, this isn't an "intervention" we can control, but it will help! Some news outlets report that summer won't do anything to COVID-19. They're half right: summer won't get R < 1, but it <em>will</em> reduce R.</p>
|
||||
|
||||
<p>For COVID-19, every extra 1° Celsius (2.2° Fahrenheit) makes R drop by 1.2%.<sup id="fnref35"><a href="#fn35" rel="footnote">35</a></sup> The summer-winter difference in New York City is 15°C (60°F), so summer will make R drop by 18%.</p>
|
||||
<p>For COVID-19, every extra 1° Celsius (2.2° Fahrenheit) makes R drop by 1.2%.<sup id="fnref36"><a href="#fn36" rel="footnote">36</a></sup> The summer-winter difference in New York City is 15°C (60°F), so summer will make R drop by 18%.</p>
|
||||
|
||||
<div class="sim">
|
||||
<iframe src="sim?stage=int-6b&format=calc" width="285" height="220"></iframe>
|
||||
|
|
@ -495,10 +495,10 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
<p>...<em>for how long?</em></p>
|
||||
|
||||
<ul>
|
||||
<li>COVID-19 is most closely related to SARS, which gave its survivors 2 years of immunity.<sup id="fnref36"><a href="#fn36" rel="footnote">36</a></sup></li>
|
||||
<li>The coronaviruses that cause "the" common cold give you 8 months of immunity.<sup id="fnref37"><a href="#fn37" rel="footnote">37</a></sup></li>
|
||||
<li>There's reports of folks recovering from COVID-19, then testing positive again, but it's unclear if these are false positives.<sup id="fnref38"><a href="#fn38" rel="footnote">38</a></sup></li>
|
||||
<li>One <em>not-yet-peer-reviewed</em> study on monkeys showed immunity to the COVID-19 coronavirus for at least 28 days.<sup id="fnref39"><a href="#fn39" rel="footnote">39</a></sup></li>
|
||||
<li>COVID-19 is most closely related to SARS, which gave its survivors 2 years of immunity.<sup id="fnref37"><a href="#fn37" rel="footnote">37</a></sup></li>
|
||||
<li>The coronaviruses that cause "the" common cold give you 8 months of immunity.<sup id="fnref38"><a href="#fn38" rel="footnote">38</a></sup></li>
|
||||
<li>There's reports of folks recovering from COVID-19, then testing positive again, but it's unclear if these are false positives.<sup id="fnref39"><a href="#fn39" rel="footnote">39</a></sup></li>
|
||||
<li>One <em>not-yet-peer-reviewed</em> study on monkeys showed immunity to the COVID-19 coronavirus for at least 28 days.<sup id="fnref40"><a href="#fn40" rel="footnote">40</a></sup></li>
|
||||
</ul>
|
||||
|
||||
<p>But for COVID-19 <em>in humans</em>, as of May 1st 2020, "how long" is the big unknown.</p>
|
||||
|
|
@ -550,7 +550,7 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
|
||||
<p><strong>To be clear: this is unlikely.</strong> Most epidemiologists expect a vaccine in 1 to 2 years. Sure, there's never been a vaccine for any of the other coronaviruses before, but that's because SARS was eradicated quickly, and "the" common cold wasn't worth the investment. </p>
|
||||
|
||||
<p>Still, infectious disease researchers have expressed worries: What if we can't make enough?<sup id="fnref40"><a href="#fn40" rel="footnote">40</a></sup> What if we rush it, and it's not safe?<sup id="fnref41"><a href="#fn41" rel="footnote">41</a></sup></p>
|
||||
<p>Still, infectious disease researchers have expressed worries: What if we can't make enough?<sup id="fnref41"><a href="#fn41" rel="footnote">41</a></sup> What if we rush it, and it's not safe?<sup id="fnref42"><a href="#fn42" rel="footnote">42</a></sup></p>
|
||||
|
||||
<p>Even in the nightmare "no-vaccine" scenario, we still have 3 ways out. From most to least terrible:</p>
|
||||
|
||||
|
|
@ -589,7 +589,7 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
</div>
|
||||
</div>
|
||||
|
||||
<p>Plane's sunk. We've scrambled onto the life rafts. It's time to find dry land.<sup id="fnref42"><a href="#fn42" rel="footnote">42</a></sup></p>
|
||||
<p>Plane's sunk. We've scrambled onto the life rafts. It's time to find dry land.<sup id="fnref43"><a href="#fn43" rel="footnote">43</a></sup></p>
|
||||
|
||||
<p>Teams of epidemiologists and policymakers (<a href="https://www.americanprogress.org/issues/healthcare/news/2020/04/03/482613/national-state-plan-end-coronavirus-crisis/">left</a>, <a href="https://www.aei.org/research-products/report/national-coronavirus-response-a-road-map-to-reopening/">right</a>, and <a href="https://ethics.harvard.edu/covid-roadmap">multi-partisan</a>) have come to a consensus on how to beat COVID-19, while protecting our lives <em>and</em> liberties.</p>
|
||||
|
||||
|
|
@ -728,27 +728,35 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
</li>
|
||||
|
||||
<li id="fn24">
|
||||
<p><a href="https://github.com/TCNCoalition/TCN#tcn-protocol">Temporary Contact Numbers, a decentralized, privacy-first contact tracing protocol</a> <a href="#fnref24" rev="footnote">↩</a></p>
|
||||
<p>To prevent "pranking" (people falsely claiming to be infected), the DP-3T Protocol requires that the hospital first give you a One-Time Passcode that lets you upload your messages. <a href="#fnref24" rev="footnote">↩</a></p>
|
||||
|
||||
<p>False positives are a problem in both manual & digital contact tracing. Still, we can reduce false positives in 2 ways: 1) By notifying Bobs only if they heard, say, 30+ min worth of messages, not just one message in passing. And 2) If the app <em>does</em> think Bob's been exposed, it can refer Bob to a <em>manual</em> contact tracer, for an in-depth follow-up interview.</p>
|
||||
|
||||
<p>For other issues like data bandwidth, source integrity, and other security issues, check out <a href="https://github.com/DP-3T/documents#decentralized-privacy-preserving-proximity-tracing">the open-source DP-3T whitepapers!</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn25">
|
||||
<p><a href="https://pact.mit.edu/">PACT: Private Automated Contact Tracing</a> <a href="#fnref25" rev="footnote">↩</a></p>
|
||||
<p><a href="https://github.com/TCNCoalition/TCN#tcn-protocol">Temporary Contact Numbers, a decentralized, privacy-first contact tracing protocol</a> <a href="#fnref25" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn26">
|
||||
<p><a href="https://www.apple.com/ca/newsroom/2020/04/apple-and-google-partner-on-covid-19-contact-tracing-technology/">Apple and Google partner on COVID-19 contact tracing technology </a>. Note they're not making the apps <em>themselves</em>, just creating the systems that will <em>support</em> those apps. <a href="#fnref26" rev="footnote">↩</a></p>
|
||||
<p><a href="https://pact.mit.edu/">PACT: Private Automated Contact Tracing</a> <a href="#fnref26" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn27">
|
||||
<p>Lots of news reports – and honestly, many research papers – did not distinguish between "cases who showed no symptoms when we tested them" (pre-symptomatic) and "cases who showed no symptoms <em>ever</em>" (true asymptomatic). The only way you could tell the difference is by following up with cases later. <a href="#fnref27" rev="footnote">↩</a></p>
|
||||
<p><a href="https://www.apple.com/ca/newsroom/2020/04/apple-and-google-partner-on-covid-19-contact-tracing-technology/">Apple and Google partner on COVID-19 contact tracing technology </a>. Note they're not making the apps <em>themselves</em>, just creating the systems that will <em>support</em> those apps. <a href="#fnref27" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn28">
|
||||
<p>Lots of news reports – and honestly, many research papers – did not distinguish between "cases who showed no symptoms when we tested them" (pre-symptomatic) and "cases who showed no symptoms <em>ever</em>" (true asymptomatic). The only way you could tell the difference is by following up with cases later. <a href="#fnref28" rev="footnote">↩</a></p>
|
||||
|
||||
<p>Which is what <a href="https://wwwnc.cdc.gov/eid/article/26/8/20-1274_article">this study</a> did. (Disclaimer: "Early release articles are not considered as final versions.") In a call center in South Korea that had a COVID-19 outbreak, "only 4 (1.9%) remained asymptomatic within 14 days of quarantine, and none of their household contacts acquired secondary infections."</p>
|
||||
|
||||
<p>So that means "true asymptomatics" are rare, and catching the disease from a true asymptomatic may be even rarer!</p>
|
||||
</li>
|
||||
|
||||
<li id="fn28">
|
||||
<p>From the same Oxford study that first recommended apps to fight COVID-19: <a href="https://science.sciencemag.org/content/early/2020/04/09/science.abb6936/tab-figures-data">Luca Ferretti & Chris Wymant et al</a> See Figure 2. Assuming R<sub>0</sub> = 2.0, they found that: <a href="#fnref28" rev="footnote">↩</a></p>
|
||||
<li id="fn29">
|
||||
<p>From the same Oxford study that first recommended apps to fight COVID-19: <a href="https://science.sciencemag.org/content/early/2020/04/09/science.abb6936/tab-figures-data">Luca Ferretti & Chris Wymant et al</a> See Figure 2. Assuming R<sub>0</sub> = 2.0, they found that: <a href="#fnref29" rev="footnote">↩</a></p>
|
||||
|
||||
<ul>
|
||||
<li>Symptomatics contribute R = 0.8 (40%)</li>
|
||||
|
|
@ -760,64 +768,64 @@ the <em>second</em>-most important idea in Epidemiology 101:</p>
|
|||
<p>And add up the pre- & a-symptomatic contacts (45% + 5%) and you get 50% of R!</p>
|
||||
</li>
|
||||
|
||||
<li id="fn29">
|
||||
<p>“None of these surgical masks exhibited adequate filter performance and facial fit characteristics to be considered respiratory protection devices.” <a href="https://www.sciencedirect.com/science/article/pii/S0196655307007742">Tara Oberg & Lisa M. Brosseau</a> <a href="#fnref29" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn30">
|
||||
<p>“The overall 3.4 fold reduction [70% reduction] in aerosol copy numbers we observed combined with a nearly complete elimination of large droplet spray demonstrated by Johnson et al. suggests that surgical masks worn by infected persons could have a clinically significant impact on transmission.” <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3591312/">Milton DK, Fabian MP, Cowling BJ, Grantham ML, McDevitt JJ</a> <a href="#fnref30" rev="footnote">↩</a></p>
|
||||
<p>“None of these surgical masks exhibited adequate filter performance and facial fit characteristics to be considered respiratory protection devices.” <a href="https://www.sciencedirect.com/science/article/pii/S0196655307007742">Tara Oberg & Lisa M. Brosseau</a> <a href="#fnref30" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn31">
|
||||
<p>Any actual scientist who read that last sentence is probably laugh-crying right now. See: <a href="https://en.wikipedia.org/wiki/Data_dredging">p-hacking</a>, <a href="https://en.wikipedia.org/wiki/Replication_crisis">the replication crisis</a>) <a href="#fnref31" rev="footnote">↩</a></p>
|
||||
<p>“The overall 3.4 fold reduction [70% reduction] in aerosol copy numbers we observed combined with a nearly complete elimination of large droplet spray demonstrated by Johnson et al. suggests that surgical masks worn by infected persons could have a clinically significant impact on transmission.” <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3591312/">Milton DK, Fabian MP, Cowling BJ, Grantham ML, McDevitt JJ</a> <a href="#fnref31" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn32">
|
||||
<p>“It is time to apply the precautionary principle” <a href="https://www.bmj.com/content/bmj/369/bmj.m1435.full.pdf">Trisha Greenhalgh et al [PDF]</a> <a href="#fnref32" rev="footnote">↩</a></p>
|
||||
<p>Any actual scientist who read that last sentence is probably laugh-crying right now. See: <a href="https://en.wikipedia.org/wiki/Data_dredging">p-hacking</a>, <a href="https://en.wikipedia.org/wiki/Replication_crisis">the replication crisis</a>) <a href="#fnref32" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn33">
|
||||
<p><a href="https://www.cambridge.org/core/journals/disaster-medicine-and-public-health-preparedness/article/testing-the-efficacy-of-homemade-masks-would-they-protect-in-an-influenza-pandemic/0921A05A69A9419C862FA2F35F819D55">Davies, A., Thompson, K., Giri, K., Kafatos, G., Walker, J., & Bennett, A</a> See Table 1: a 100% cotton T-shirt has around 2/3 the filtration efficiency as a surgical mask, for the two bacterial aerosols they tested. <a href="#fnref33" rev="footnote">↩</a></p>
|
||||
<p>“It is time to apply the precautionary principle” <a href="https://www.bmj.com/content/bmj/369/bmj.m1435.full.pdf">Trisha Greenhalgh et al [PDF]</a> <a href="#fnref33" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn34">
|
||||
<p><strong>"We need to save supplies for hospitals."</strong> <em>Absolutely agreed.</em> But that's more of an argument for increasing mask production, not rationing. In the meantime, we can make cloth masks. <a href="#fnref34" rev="footnote">↩</a></p>
|
||||
<p><a href="https://www.cambridge.org/core/journals/disaster-medicine-and-public-health-preparedness/article/testing-the-efficacy-of-homemade-masks-would-they-protect-in-an-influenza-pandemic/0921A05A69A9419C862FA2F35F819D55">Davies, A., Thompson, K., Giri, K., Kafatos, G., Walker, J., & Bennett, A</a> See Table 1: a 100% cotton T-shirt has around 2/3 the filtration efficiency as a surgical mask, for the two bacterial aerosols they tested. <a href="#fnref34" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn35">
|
||||
<p><strong>"We need to save supplies for hospitals."</strong> <em>Absolutely agreed.</em> But that's more of an argument for increasing mask production, not rationing. In the meantime, we can make cloth masks. <a href="#fnref35" rev="footnote">↩</a></p>
|
||||
|
||||
<p><strong>"They're hard to wear correctly."</strong> It's also hard to wash your hands according to the WHO Guidelines – seriously, "Step 3) right palm over left dorsum"?! – but we still recommend handwashing, because imperfect is still better than nothing.</p>
|
||||
|
||||
<p><strong>"It'll make people more reckless with handwashing & social distancing."</strong> Sure, and safety belts make people ignore stop signs, and flossing makes people eat rocks. But seriously, we'd argue the opposite: masks are a <em>constant physical reminder</em> to be careful – and in East Asia, masks are also a symbol of solidarity!</p>
|
||||
</li>
|
||||
|
||||
<li id="fn35">
|
||||
<p>“One-degree Celsius increase in temperature [...] lower[s] R by 0.0225” and “The average R-value of these 100 cities is 1.83”. 0.0225 ÷ 1.83 = ~1.2%. <a href="https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3551767">Wang, Jingyuan and Tang, Ke and Feng, Kai and Lv, Weifeng</a> <a href="#fnref35" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn36">
|
||||
<p>“SARS-specific antibodies were maintained for an average of 2 years [...] Thus, SARS patients might be susceptible to reinfection ≥3 years after initial exposure.” <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/">Wu LP, Wang NC, Chang YH, et al.</a> "Sadly" we'll never know how long SARS immunity would have really lasted, since we eradicated it so quickly. <a href="#fnref36" rev="footnote">↩</a></p>
|
||||
<p>“One-degree Celsius increase in temperature [...] lower[s] R by 0.0225” and “The average R-value of these 100 cities is 1.83”. 0.0225 ÷ 1.83 = ~1.2%. <a href="https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3551767">Wang, Jingyuan and Tang, Ke and Feng, Kai and Lv, Weifeng</a> <a href="#fnref36" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn37">
|
||||
<p>“We found no significant difference between the probability of testing positive at least once and the probability of a recurrence for the beta-coronaviruses HKU1 and OC43 at 34 weeks after enrollment/first infection.” <a href="http://www.columbia.edu/%7Ejls106/galanti_shaman_ms_supp.pdf">Marta Galanti & Jeffrey Shaman (PDF)</a> <a href="#fnref37" rev="footnote">↩</a></p>
|
||||
<p>“SARS-specific antibodies were maintained for an average of 2 years [...] Thus, SARS patients might be susceptible to reinfection ≥3 years after initial exposure.” <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/">Wu LP, Wang NC, Chang YH, et al.</a> "Sadly" we'll never know how long SARS immunity would have really lasted, since we eradicated it so quickly. <a href="#fnref37" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn38">
|
||||
<p>“Once a person fights off a virus, viral particles tend to linger for some time. These cannot cause infections, but they can trigger a positive test.” <a href="https://www.statnews.com/2020/04/20/everything-we-know-about-coronavirus-immunity-and-antibodies-and-plenty-we-still-dont/">from STAT News by Andrew Joseph</a> <a href="#fnref38" rev="footnote">↩</a></p>
|
||||
<p>“We found no significant difference between the probability of testing positive at least once and the probability of a recurrence for the beta-coronaviruses HKU1 and OC43 at 34 weeks after enrollment/first infection.” <a href="http://www.columbia.edu/%7Ejls106/galanti_shaman_ms_supp.pdf">Marta Galanti & Jeffrey Shaman (PDF)</a> <a href="#fnref38" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn39">
|
||||
<p>From <a href="https://www.biorxiv.org/content/10.1101/2020.03.13.990226v1.abstract">Bao et al.</a> <em>Disclaimer: This article is a preprint and has not been certified by peer review (yet).</em> Also, to emphasize: they only tested re-infection 28 days later. <a href="#fnref39" rev="footnote">↩</a></p>
|
||||
<p>“Once a person fights off a virus, viral particles tend to linger for some time. These cannot cause infections, but they can trigger a positive test.” <a href="https://www.statnews.com/2020/04/20/everything-we-know-about-coronavirus-immunity-and-antibodies-and-plenty-we-still-dont/">from STAT News by Andrew Joseph</a> <a href="#fnref39" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn40">
|
||||
<p>“If a coronavirus vaccine arrives, can the world make enough?” <a href="https://www.nature.com/articles/d41586-020-01063-8">by Roxanne Khamsi, on Nature</a> <a href="#fnref40" rev="footnote">↩</a></p>
|
||||
<p>From <a href="https://www.biorxiv.org/content/10.1101/2020.03.13.990226v1.abstract">Bao et al.</a> <em>Disclaimer: This article is a preprint and has not been certified by peer review (yet).</em> Also, to emphasize: they only tested re-infection 28 days later. <a href="#fnref40" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn41">
|
||||
<p>“Don’t rush to deploy COVID-19 vaccines and drugs without sufficient safety guarantees” <a href="https://www.nature.com/articles/d41586-020-00751-9">by Shibo Jiang, on Nature</a> <a href="#fnref41" rev="footnote">↩</a></p>
|
||||
<p>“If a coronavirus vaccine arrives, can the world make enough?” <a href="https://www.nature.com/articles/d41586-020-01063-8">by Roxanne Khamsi, on Nature</a> <a href="#fnref41" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn42">
|
||||
<p>Dry land metaphor <a href="https://www.statnews.com/2020/04/01/navigating-covid-19-pandemic/">from Marc Lipsitch & Yonatan Grad, on STAT News</a> <a href="#fnref42" rev="footnote">↩</a></p>
|
||||
<p>“Don’t rush to deploy COVID-19 vaccines and drugs without sufficient safety guarantees” <a href="https://www.nature.com/articles/d41586-020-00751-9">by Shibo Jiang, on Nature</a> <a href="#fnref42" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
<li id="fn43">
|
||||
<p>Dry land metaphor <a href="https://www.statnews.com/2020/04/01/navigating-covid-19-pandemic/">from Marc Lipsitch & Yonatan Grad, on STAT News</a> <a href="#fnref43" rev="footnote">↩</a></p>
|
||||
</li>
|
||||
|
||||
</ol>
|
||||
|
|
|
|||
|
|
@ -404,7 +404,13 @@ Here's how it works:
|
|||
|
||||
|
||||
|
||||
(& [here's the full comic](https://ncase.me/contact-tracing/))
|
||||
([Here's the full comic](https://ncase.me/contact-tracing/). Details about "pranking"/false positives/etc in footnote:[^dp3t_details])
|
||||
|
||||
[^dp3t_details]: To prevent "pranking" (people falsely claiming to be infected), the DP-3T Protocol requires that the hospital first give you a One-Time Passcode that lets you upload your messages.
|
||||
|
||||
False positives are a problem in both manual & digital contact tracing. Still, we can reduce false positives in 2 ways: 1) By notifying Bobs only if they heard, say, 30+ min worth of messages, not just one message in passing. And 2) If the app *does* think Bob's been exposed, it can refer Bob to a *manual* contact tracer, for an in-depth follow-up interview.
|
||||
|
||||
For other issues like data bandwidth, source integrity, and other security issues, check out [the open-source DP-3T whitepapers!](https://github.com/DP-3T/documents#decentralized-privacy-preserving-proximity-tracing)
|
||||
|
||||
Along with similar teams like TCN Protocol[^tcn] and MIT PACT[^pact], they've inspired Apple & Google to bake privacy-first contact tracing directly into Android/iOS.[^gapple] (Don't trust Google/Apple? Good! The beauty of this system is it doesn't *need* trust!) Soon, your local public health agency may ask you to download an app. If it's privacy-first with publicly-available code, please do!
|
||||
|
||||
|
|
@ -416,7 +422,7 @@ Along with similar teams like TCN Protocol[^tcn] and MIT PACT[^pact], they've in
|
|||
|
||||
But what about folks without smartphones? Or infections through doorknobs? Or "true" asymptomatic cases? Contact tracing apps can't catch all transmissions... *and that's okay!* We don't need to catch *all* transmissions, just 60%+ to get R < 1.
|
||||
|
||||
(Rant about the confusion about pre-symptomatic vs "true" asymptomatic. "True" asymptomatics are rare:[^rant])
|
||||
(Footnote rant about the confusion between pre-symptomatic vs "true" asymptomatic – "true" asymptomatics are rare:[^rant])
|
||||
|
||||
[^rant]: Lots of news reports – and honestly, many research papers – did not distinguish between "cases who showed no symptoms when we tested them" (pre-symptomatic) and "cases who showed no symptoms *ever*" (true asymptomatic). The only way you could tell the difference is by following up with cases later.
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue