Saturday, October 17, 2020

Grim Guesses, Round 3 (Recap, further predictions)

 Original here.


We are now well past 200,000 deaths.  I hope we will not get to half a million- maybe we'll plateau out around 400,000! - but it doesn't look good.

In April I said this: 

"I think that some of the places (like NZ) that have done the best containment are screwed in the absence of widespread testing - even worse off than NYC- because the moment anything reopens it will spread very fast."

Europe is up to 100,000 cases a day over a population roughly twice the US's.  New Zealand continues to have strong containment and minimal community spread, mainly by maintaining high levels of testing, isolation, and government response. Europe has the problem I predicted: not enough testing for actual containment, and eventually it becomes both unreasonable and impossible to keep everything closed for 18 months.  The US and European outbreaks have both become un-containable.

I heard someone say last week, "Testing describes an outbreak that has already happened."  Remember that next time you hear someone say that more testing or more contact tracing will actually prevent outbreaks.  It may help contain them temporarily, but unless you catch every single asymptomatic carrier, there is going to be untraceable community spread.

On to more depressing predictions!  I am doing a best guess on many of these numbers because I don't have time to read 100 research articles.  

We will find that there is almost no surface to person transmission (the only credible case report to date does not, in fact, demonstrate any actual surface to person transmission; elevators have poor air circulation and nobody even checked; see also the Korea call center outbreak). Reasoning: this has been going on for 7 months and the absence of evidence is not evidence of absence, but there are also excellent data documenting person to person airborne droplet transmission. 

People will continue to get sporadically reinfected, and more-serious second rounds will be found predominantly in people with a mild first infection (THAT IS HOW THE IMMUNE SYSTEM WORKS).  The actual percentages will be impossible to come by, because of technical limitations of our current test system.  I predict that no more than 1% of people with 'severe' (feverish, symptomatic) infection will get re-infected within 18 months- and probably less - and no more than 10% of people with mild/asymptomatic illness - probably less.   

The pandemic will not be 'over' before December 2021, because even after a vaccine (likely widespread by June/July) sporadic outbreaks will continue due to low immunogenicity, waning of all immune responses over time, low uptake, and Americans' stupid refusal to continue wearing masks in public.

Schools that re-open will have sporadic transmission events, but primary grades will not be a major driver of this.  Teachers will continue to infect each other at some low rate, however, and children will continue getting sick from family members.

This winter will be a complete !@$!%%! disaster in terms of schools, because everyone is very bad at statistics (and kids get colds in the winter, and cough is an extremely nonspecific symptom).

If Biden is elected, things may get less bad, but they're still going to be pretty bad.  If Tr!mp is re-elected, I'm looking to leave the country.

Colleges will mostly stay open and deal with their outbreaks, because otherwise nobody gets paid.

(As a side note, be skeptical of the 'small gatherings are driving transmission.'  Yes, they are, but mostly because there are not large gatherings.  Where are people together, breathing on each other?  Small gatherings, and colleges.  If there were no gatherings, it would be 'going to the grocery' or 'nocosomial infections' or something.  This is like saying most people who are in car accidents were driving at the time.) 


4 comments:

  1. I appreciate the predictions and update! Is it true that many Covid patients have severe problems due to an overreacting immune system? From research this spring, Covid-infected people taking immunosuppressants were not more likely to die. Perhaps a second infection is more severe than a first because of a heightened immune response. Or, as you said, these reinfected people are outliers.

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    1. so far all the more severe second infections have been in mild cases (as far as I've seen https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30783-0/fulltext - I've only seen 5? And the 5th was in chemo). It is possible that someone with a severe infection will have a severe second round in quick succession but based on all the immunology data, it's unlikely.

      "Overreacting immune system" is not quite it- more that when initial response doesn't clear infection, the immune response continues, sometimes into cytokine storm. This is a general mechanism by which people die of viruses, rather than of virus-catalyzed pneumonia, for example. SO, yes, people with this severe response following 10+ days of illness are more likely to die, but not because of the response necessarily. (Related: 50% of patients on vents for any reason typically die.)

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  2. Sarah8:25 AM

    Is the testing good enough to use widely ('screen') in asymptomatic population though? Is that what they're doing in NZ, or have they just had few enough cases that they could all be containted? I've only seen sensitivity / specificity reported for symptomatic, and it's OK but not brilliant, so might get too many false positive/negative to be useful in asymptomatic people. Or is lack of widespread testing in asymptomatic solely down to cost? (here in UK they weren't even testing symptomatics here for a long time (unless taken to hospital), and now you can request a test if symptomatic, but there's no obligation to do this, and advice remains same anyway (self-care at home).

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    1. It's good enough if used correctly (which nobody is). 1) it could be standardized to total RNA, which would lower the false-negative rate, since right now it is non-quantitative; 2) if you test people sequentially and regularly, it will catch almost everyone; 3) NZ is a combo of both, but see also Germany (https://www.bbc.com/news/54181291)). For sure the US and the UK are past the point of containment, but there are other parts of Europe where, a few weeks ago, more testing could have slowed it down. We're all at the point where hospital overload and all-cause excess mortality are a real concern.

      False positives are relatively rare; what happens instead are positives on people who may no longer be contagious, which is a different kind of error really. They do in fact have shed viral RNA, but it's not clinically relevant.

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