COVID topic vol 2

[jacob]

Standard HS probability thinking is not generally applicable to rare events (outliers). Lets say you observe some really strange outlier in 2 cases out of 50000 samples, whereas the other 49998 cases are pretty normal (much like each other).

If the 2 outliers don't matter as long as their contribution divided by 50000 is small, you can do HS level math. Expectation values are reasonable and probabilities are well-defined. For example, if it was a $100 portfolio the expectation value might be $0.03 per day. It also makes sense to calculate the variance.

However, if the number or size of the outliers (or potential outliers) divided by the sample space is large, HS math will lead you down the wrong path to a Dunning Kruger kind of confidence.

If you look at that portfolio (and understand it as a metaphor for living) for a while (or look at an ensemble of portfolios---a metaphor for different people living for a while) and focus on the whole history (or set of histories) as opposed to normally only comprehending what is just in front of your personal nose on that particular day (possibly extending to anecdotal experiences of friends and family), there might be a day where the drawdown is $40 and another where it's $95. These outliers indicate that you're presuming the wrong distribution for your math. Your "lets assume" is broken.

However, [because your sample while large is not that large] you don't know the real outlier count is 2 or 1 or 3 or maybe 10 (you might have gotten a lucky sample space). If you really knew that the outlier only happened once in 50000, you'd be good. However, it might happen 10x as much in which case your distribution is broken. In particular if you only have a few outliers, you also don't know if the real cost is $40 or $95 or whether it's $89, $57, $30, and $100.

Some of the late 19th century stats were developed exactly to deal with such small sample events, e.g. t-tests, chi2, ...This made it possible to say not only things like "the probability is only 0.1%" but also "the probability is 0.1% but we're only 70% confident that this is true" and "the variation is generally small but there's a 10% chance this is incorrect" or "the probability that data fits the assumed distribution is 92%".

It would therefore be wise to analyze just how an outlier drawdown might come about because the fact that they're there shows that there's something about the system or process you don't know. The solution might turn out to be rather cheap. Maybe it's all due to a particular substrategy which can be modified slightly at a rather small cost. Like an O-ring on the space shuttle. Or finding some other cheaper way to signal political allegiance or the size of one's cojones than not wearing a mask. Or not.

Using the wrong decision process the right way is riskier than using the right decision process the wrong way because of the unwarranted confidence in the former case. In the market, trading against the former is much more profitable than trading against someone who realizes they don't know what they're doing but dabble a bit anyway. As for COVID trading strats, insofar it was possible to buy options on individual estates, it it's no longer that hard to figure out which ones are currently undervalued by their owners. It would be rather mercenary though.

[nomadscientist]

You have to decide what is your goal in life which usually isn't "sit alone in a house for as long as possible" (in which case you still accept showering and walking up and down the stairs and operating kitchen equipment and gas explosions and so on).

Generally you have to accept some tail risks in order to have a non-zero probability of achieving that goal. In which case it absolutely makes sense to weight them by likelihood and not purely by maximum harm, accepting some chance that you will fail to achieve your goals because of some tail catastrophe.

In some situations, sheltering from covid might make sense, e.g. with a life that's stable and house-based already, why not? (but you won't stop showering or cooking meals)

In others, it makes less sense (unemployed 37 year old single person).

[Peanut]

@UK: Why not just put a moratorium on visiting until you can get vaccinated? Or do you not want to?
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@Ego: That is fascinating information about ivermectin. I had not read about it before. It's perplexing that it has not been widely used or recommended. It makes me lose trust once again in the administrative and medical powers that be.
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Curious if anyone on the forum has already decided not to get vaccinated? I am leaning towards doing it, although it seems I have to wait till 83% of the rest of the population does. The problem is I know several anti-vaxxers among my acquaintance. They either cherry-pick or wholly forego vaccines for their kids. Among my close friends all are committed to vaccinations, but I regularly see the former group (always outside), and I guess their pseudoscience just begins to wear on me. While I can diagnose their pathology as a drive for purity/obsession with toxins, or a sense of superiority, etc., I'm not naturally scientific-minded myself so it's difficult to figure out if this not just new but new kind of vaccine with no long-term safety study is worth the risk. I definitely do want DH to get it, as does he, but he is a man over 45 and at least 15 pounds overweight. Btw something I don't understand about vaccines is why they are not calibrated to individual body size the way some medications are. Isn't this why the children's vaccine is not ready yet? The dose/concentration will be lower to adjust for their size? Or is it going to be the exact same thing and they just need to run through the trials?

[7Wannabe5]

Yup, you gotta know the difference between uncertainty and risk.

I, for one, would be in favor of granting all citizens the right to literally display their cojones in public in exchange for taking on the responsibility of wearing a mask.

[jacob]

Btw something I don't understand about vaccines is why they are not calibrated to individual body size the way some medications are. Isn't this why the children's vaccine is not ready yet? The dose/concentration will be lower to adjust for their size? Or is it going to be the exact same thing and they just need to run through the trials?

The immune system works in mysterious ways. Vaccine dosage doesn't necessarily show a linear response for immunity like tranquilizer does for sedation. This is similar to how two small lessons might be more informative than one big lesson as the information has had time to sink in and gets a refresher. (Also why the side-effects of the second shot might be stronger as the immune system reacts faster and harder recognizing the enemy again.) Even one small lesson might be more useful than a big whopper of lesson as the system pays more attention.

The reason the "children's vaccine" is not ready yet is because trials haven't been run. It will likely be the exact same vaccine once trials are run and it has been approved for 0-18 yos. 0-18 yos weren't considered a priority for approval since adverse effects from the disease are rare. Perhaps this will change since there's some indication that the new mutation is more adverse to the younger crowd. However, cross immunization is expected.

As far the other question. I will get vaccinated ASAP which in my case is the last group before the 0-18 yos lest they further stratify by age. For now, I'm in the 18-55 group. The existence of (older) anti-vaxxers just means that I can get vaccinated sooner, so thanks for that.

The efficacy is on the 95% level, so it's like have an N95 grafted onto your face, sort of. What 95% really means is that the vaccine only "took" in 95% of the cases, not that it filters 95% of the incoming air like the mask. However, since the priors aren't known (until you get sick), you can add the probabilities, e.g. vaccine+N95 = 99.75% which is almost as good as P100. A vaccine plus cloth/surgical would be 1-0.7*0.05 = 96.5% which is also good ... and mask-less plus vaccine would be 95%. This is presuming you're encountering a maskless non-vaccinated person. Two vaccinated N95s meeting would be 1 bad outcome in 160,000 meetups ... rest left as an exercise for the reader. These calculations can be compensated for duration, exposure, confinement, distance, and so on.

What's more important than the percentage on a personal level is that none of the 5% developed any adverse disease outcomes insofar they did get COVID. That's the benefit I want. In short, the vaccine reduces probability by a factor 20x which is nice. But it also reduces maximum drawdown risk to a mild course which is crucial (at least to me).

[Ego]

@Ego: That is fascinating information about ivermectin. I had not read about it before. It's perplexing that it has not been widely used or recommended. It makes me lose trust once again in the administrative and medical powers that be.

This website is tallying all of the studies https://ivmmeta.com/

•100% of the 28 studies to date report positive effects. Early treatment is more successful, with an estimated reduction of 87% in the effect measured using a random effects meta-analysis, RR 0.13 [0.04-0.40]. Prophylactic use also shows high effectiveness.

•100% of the 10 Randomized Controlled Trials (RCTs) report positive effects, with an estimated reduction of 74%, RR 0.26 [0.12-0.56].
•The probability that an ineffective treatment generated results as positive as the 28 studies to date is estimated to be 1 in 268 million (p = 0.0000000037).

Early treatment: 87% improvement RR 0.13 [0.04-0.40]
Late treatment: 48% improvement RR 0.52 [0.36-0.74]
Pre-Exposure: Prophylaxis 91% improvement RR 0.09 [0.03-0.26]
Post-Exposure: Prophylaxis 90% improvement RR 0.10 [0.06-0.17]
Total 28 studies 195 authors 12,560 patients
RCT 10 studies 82 authors 1,759 patients

I purchased some back in early April but have not used it yet as it seems pre and post exposure results are similar.

[chenda]

I went for a Covid test this afternoon. I didn't realise I'd have to do it myself, it's not easy.

Now I think my symptoms are worsening, coughing, short of breath, and weird adrenaline rushes. I don't know how this has happened I am so obsessively vigilant about infection.

[Ego]

Not just nursing home staff.....

https://www.latimes.com/california/stor ... ine-access

At St. Elizabeth Community Hospital in Tehama County, fewer than half of the 700 hospital workers eligible for the vaccine were willing to take the shot when it was first offered. At Providence Holy Cross Medical Center in Mission Hills, one in five frontline nurses and doctors have declined the shot. Roughly 20% to 40% of L.A. County’s frontline workers who were offered the vaccine did the same, according to county public health officials.

So many frontline workers in Riverside County have refused the vaccine — an estimated 50% — that hospital and public officials met to strategize how best to distribute the unused doses, Public Health Director Kim Saruwatari said.

Perhaps some of the decliners are those who were born elsewhere, received the BCG vaccine when they were children and believe that it provides sufficient protection.

https://trialsitenews.com/cedars-sinai- ... 9-impacts/

This most recent observational study involves the investigation in over 6,000 healthcare workers in the Cedars-Sinai Health System for evidence of antibodies to SARS-COV-2: those workers that had received BCG vaccinations, representing 30% of the total number of subjects in the study, were identified as significantly less likely to test positive for COVID-19-related antibodies in their blood or to report succumbing to the virus, or experiencing coronavirus-like symptoms within the previous six months as compared to those who did not receive BCG.

[Viktor K]

Alleged concern now of vaccines being less effective against strain circulating in South Africa.

[Alphaville]

Now I think my symptoms are worsening, coughing, short of breath, and weird adrenaline rushes. I don't know how this has happened I am so obsessively vigilant about infection.

oh damn, so sorry to hear this. try to not stress out much, watch sone funny movies, and eat raw onion and garlic and maybe ginger and lemon which have a reputation (real or placebo, i'll take whatever works) of helping with immunity/airways. (we took during suspected case back in march).

i like to marinate onion in a lime/vinegar mixture for a bit makes a crunchy salad you can use to top your lentils. slice, rinse in saltwater to remove the excess bite, toss with citrus juice, chili peppers, dash of vinegar, ready in about 20'. potent stuff!

[7Wannabe5]

@chenda:

Don’t hesitate to go get some steroids if you are experiencing significant shortness of breath. Covid is not Stoic challenge. Be well

[Viktor K]

Boris puts all of England on lockdown.

Second dip of recession predicted by experts soon.

Meanwhile US executive in denial over election and focused on Georgia.

Vaccination well behind schedule in US.

My hot take: US COVID continues to skyrocket, new strain spreads unchecked. How much time before US hospitals overwhelmed? Seems like 2 months if following the UK timeline, places like LA much sooner.

[TheWanderingScholar]

Yeah, I think the US is not even close to being half way out of the wood work yet, sadly.

[chenda]

@Alphaville @7wannabe5 - Many thanks for the tips, fortunately the test result was negative. I seemed to have improved today and breathing is now normal.

[Alphaville]

fortunately the test result was negative.

great news! stay well...

[Ego]

Peter Doshi, editor at the BMJ, is demanding raw data from the vaccine trials. The 95% effective claim is looking very sketchy.

https://blogs.bmj.com/bmj/2021/01/04/pe ... -raw-data/

All attention has focused on the dramatic efficacy results: Pfizer reported 170 PCR confirmed covid-19 cases, split 8 to 162 between vaccine and placebo groups. But these numbers were dwarfed by a category of disease called “suspected covid-19”—those with symptomatic covid-19 that were not PCR confirmed. According to FDA’s report on Pfizer’s vaccine, there were “3410 total cases of suspected, but unconfirmed covid-19 in the overall study population, 1594 occurred in the vaccine group

With 20 times more suspected than confirmed cases, this category of disease cannot be ignored simply because there was no positive PCR test result. Indeed this makes it all the more urgent to understand. A rough estimate of vaccine efficacy against developing covid-19 symptoms, with or without a positive PCR test result, would be a relative risk reduction of 19%, far below the 50% effectiveness threshold for authorization set by regulators.”

[Viktor K]

So eyeballing a roughly 50:50 split on unconfirmed COVID (wtf does that even mean?) between the placebo and vaccine group, and a... 1:20 split on confirmed COVID between the vaccine and placebo group.

Does that really change efficacy?

Also, I've never seen bmjopinon blog as a news source... is it reliable either way? Looks like it's an open submission with criteria being 'well-written'.

BMJ Opinion provides comment and opinion written by The BMJ's international community of readers, authors, and editors. We welcome submissions for consideration. Your article should be clear, compelling, and appeal to our international readership of doctors and other health professionals.

Being skeptical.

some or many of the suspected covid-19 cases may be due to a different causative agent.

Okay...

at the end of the day, it is not average clinical severity that matters, it’s the incidence of severe disease that affects hospital admissions

That's what I was thinking as well

EDIT: Ideally vaccine is efficacious, with rate of mutation... probably going to be annual vaccines like flu? Imagining a vaccinated populace (unlikely globally for some time), with no restrictions, would mean more opportunity to mutate.

[George the original one]

USA passed 360,000 COVID-19 deaths today. That's the past decade's worth of flu death per the CDC estimates.

[white belt]

USA hits ~4k deaths a day, projected for 150k deaths in next month.

Has anyone seen any information on recent USA projections for herd immunity? I wonder with the slow vaccine rollout (slow distribution+people refusing it) and so many deaths, how long it will take for the vaccine to actually have an effect on those numbers? I remember that vaccine development article from a few months back talked about how it might end up that we reach herd immunity from deaths around the same time as vaccine rollout is complete, but I haven’t seen any data to back that up yet.

Edit: One projection I saw from IHME was 1 million deaths in USA for herd immunity (there might be better/more accurate figures elsewhere). If the 150k a month death rate continues then we’d pass that mark in 4.25 months, just in time for summer.

[jacob]

@wb - Back of the envelope says 150k deaths per month with a case fatality rate of 1.7% (just using today's integrated numbers from worldometers) leads to ~9M cases per month ... the actual number of cases will be higher, but I have no good way of estimating that since the positive test rates in the US are rather higher (meaning that substantial numbers slip through). In any case ~9M/month > current vaccination rates...

Vaccination rates should be picking up with more experience.

Currently, the highest infected states are ND and SD with 12 and 13% of the population having had it. (Possibly including double counting people who've had it twice. This happens but my understanding is that it's rare.) That's after almost a year. Insofar we maintain the current game of behaviorally controlling R so as not to overwhelm the medical infrastructure, getting herd immunity the hard way is going to take years. Word is that vaccine roll out should be done by this year.

It will be interesting to see what happens near the end when vaccination counts are high enough to ease lockdowns enough to make the unvaccinated get sick faster. This seems rather nonlinear to me.