Omicron Post #12

It involved a backlog, but the USA reported over 1 million cases yesterday. That’s a lot of cases, and we’re missing a ton more of them. Schools, hospitals and all businesses face massive disruptions from people unable to work, even with the new CDC isolation guidelines.

So far, we’re holding up well, better than I expected even after previous severity estimates were adjusted. Things are going to be severely disrupted for a while, but not as severely as we might have feared, and even if we get a median outcome that is much better than the mean outcome given the tail risk of true disaster.

Still, brace yourself, and choose how you want to handle the next month or two. If you’re serious about trying to avoid Omicron, now is the time to show it.

Vaccine Effectiveness

A Danish study from earlier found large negative vaccine effectiveness. Large negative effectiveness is not a thing, we would know about it and the world would look very different, but anti-vax people are of course jumping on it and the attempt to explain isn’t going all that well. Which it mostly shouldn’t, in my view, because when you get nonsense results that are clearly nonsense results but you don’t control properly and so you publish anyway, what else do you expect?

I looked at the paper. They control for the basics, including geographical region.

VE was calculated as 1-HR with HR (hazard ratio) estimated in a Cox regression model adjusted for age, sex and geographical region, and using calendar time as the underlying time scale.

I’ve heard reasons that make it possible for vaccine effectiveness to go negative, but those reasons don’t seem compatible with large positive effectiveness shortly after two doses, and large positive effectiveness again after a booster shot.

More than that, check the sections on severity and hospitalization below. They make it very clear that being vaccinated offers a lot of effective protection and is very much a good idea, and getting boosted is an even better idea.


CDC lifts the pause on anti-Delta monoclonal antibodies, says they can be used if Delta is still in your region and there aren’t other options available. My guess is there are still some places in America where this makes sense, since even a small chance of getting the old effectiveness is better than doing nothing, but this window is ending rapidly.

Quarantine, Isolation and Travel

Instead of ending all travel-based quarantines because they no longer make any sense, many new travel restrictions are being imposed.

This is deeply stupid. It makes sense to make someone quarantine if they are at much higher risk than the surrounding population, and there’s some hope of stopping the spread. Two places having mutual travel restrictions usually means both are making a mistake. These quarantines are quite expensive (as are the required PCR tests, which given the need for reliable results often cost hundreds).

What prompted this was that I noticed that France added the United States to their ‘red list’, including the first comment as a ‘same energy’ to indicate the mindset.

France has twice as many cases per capita as the United States right now, and about two thirds of the death rate.

At this point, quarantines even for people with large known exposures seem questionable. If you learn you’ve been exposed to Covid-19, you have not received that many bits of information, and it’s not clear how much behavior change is justified. Not zero, especially if you’re going to potentially see vulnerable people, but if you used the old thresholds for quarantine you would (quite literally) never leave the house.

At least it’s better than universal isolation, such as the curfews in Quebec:


Whereas Princeton is telling its students they can’t leave the county after they arrive on campus. Not the country, the county. I am confused how they think this will help.

Delhi is locking down for the weekend. I have no idea what this hopes to accomplish. Reported cases in India are up 488% in a week (presumably they’re missing most of them), but what good will three days do? Allow the countryside to catch up a bit?

Here’s a graphical argument liked by Mina from Saul Kato for why you need a negative test before you end isolation (the thread contains more details, but we’ve seen those before).

The CDC’s guidance is definitely having an impact, for better and for worse.


If you tell someone who is symptomatic to come back to work, the results to your business are not, in expectation, going to be what you are hoping for.

Yes, some amount of this was inevitable from the new guidelines, especially given the lack of a testing requirement, but restaurants have been making sick people come in when they very much should not come in (even if it means closing the place down for a bit) for a long time and they are not about to stop now.

There are some who are going to treat the CDC requirements as a minimum, without which doing anything is crazy. Others are going to treat it as a maximum, and then make compromises. You do have to set the requirements knowing both of these things will happen. It’s a hard problem.

Doctors being told to come back in four days with no test means they’re going back while still infectious. Is that better or worse than having patients go without care due to lack of staffing? I don’t know.

I do know that this Colbert clip shows how symbolic the whole thing is. Colbert can come back in five days if he wears a mask at all times including during the monologue when he’s dozens of feet away from the nearest person (or if not, he certainly could be) but otherwise he needs to wait ten and she doesn’t tell him to test. The need to pretend that the guidelines make sense forces director Walensky into Obvious Nonsense territory. She did have the decency to nervously force herself to laugh.

Disruptions other than Hospitals

Staffing shortages shut things down. A substantial portion of local restaurants have been shut down at some point by now, for example, along with several subway lines.

When we check in on our ‘not an alarmist’ account, we see these: A county in Maryland cancels school bus routes. Multiple school districts close entirely. Milwaukee going to virtual schooling due to staffing shortages. So is Newark. A prediction that almost all schools will close during January. All NYC Apple stores are closed. A third of Philadelphia classrooms forced to go remote on Tuesday.

I updated a small amount in favor of things being somewhat less disrupted than I expected, because given the information networks available, I would have expected the account to find more and bigger examples of school disruptions. Still, Milwaukee is big, and Philadelphia is big.

So far, both my children’s schools remain open, albeit with large drops in attendance and a bunch of michegas regarding testing.

There’s a reasonable argument that I buy, which says that if you believe school is what its advocates say it is, schools should be kept open as long as possible. NYC Mayor Eric Adams (man saying that is such a relief) definitely buys that, saying that ‘the safest place for our children is in a school building. We are going to keep our schools open.’

The claim that a school is ‘the safest place for our kids’ in a pandemic is grade-A Obvious Nonsense, and presumably comes from this logic:

  1. We must always do The Safest Thing for our kids.
  2. We need to open the schools.
  3. Therefore, the schools are The Safest Thing.

The problem is that people mostly aren’t willing to let such things ‘muddle through’ in any sense, so this kind of will often won’t generate a way.

Schools aren’t going to be allowed to say ‘yes, the school is going to involve a lot of Covid-19’ and instead imposes lots of tests, which finds cases, which forces isolations and shuts down classrooms. Even without that, staffing shortages would still make it impossible to keep many schools and classrooms open, because the system does not have enough slack for such an event.

Businesses and other activities that can survive with limited on-site staff by muddling through, or that are important enough that people should come in anyway if it comes to that, should mostly be able to stay open.

Those that cannot take that approach are going to face a lot of disruption over the next few weeks. Be ready.

Ideally we can find the right balance of shutting versus muddling. It’s difficult.


One million cases reported in one day. Wow. Backlogs from New Year’s and the weekend were involved, to be sure, but still, wow.

Georgia didn’t update because too much data overwhelmed the system, so you can guess how well things are going there.

Seattle offers some strange graphs, where if we use SGTF deletion as our guide, we see Omicron fading away and Delta increasing. I was told this was from Trevor Bedford, who has otherwise been an excellent data source, but there’s simply no way the graphs are indicating what they say they are. One possibility is that the other version of Omicron, that doesn’t have SGTF deletion, is rising in relative terms.

San Francisco infections may already be peaking. My guess is this is premature, but we are seeing data points in this direction. Could be the same holiday-related fluctuations, as well.


New York is going to start having hospitals report how many people are hospitalized ‘with Covid’ versus ‘for Covid’ starting in five days. This will be a great source of data, hopefully exactly in time to not much matter.

This article highlights that 30% of EMS workers in NYC are currently out sick. The thing is, they’re not all out sick, they’re all sick or isolating.

Amid the spike in calls, 30% of the city’s 4,400 emergency medical services (EMS) staff were out sick as of Wednesday, according to Frank Dwyer, an FDNY spokesperson. He added that the surge in people out sick was a combination of COVID-positive workers, those who’d been exposed and staff awaiting test results.

That means we can’t use the 30% to estimate prevalence, and it also means that we’re holding too many people back. If you’re an EMS worker, yes, you’ve been exposed. That’s the job when 10%+ of the city has Covid-19 at once, how could you not be exposed?

Having such people isolate after an exposure or while waiting for test results is going to do far more harm than good at this point. It’s also fully incompatible with ending isolation after a positive test after only five days without a negative test, although I assume the EMS is ignoring that suggestion and requiring the negative tests anyway.

Nate Silver notes a decline in Google searches for Covid symptoms in NYC.


My guess is that at this point everyone’s already Googled a lot, and a lot of this is pseudo-random, but it is an interesting data point. Nate also notes that the positive test rate has stabilized at 23%, which seems like stronger evidence that we may be at or near the peak.


Good news from London.

There’s been enough time that if John’s adjustment is remotely reasonable, the cohort that got sick earlier was at little risk. The question now is what will happen with the elderly, for whom not as much time has passed.


This is the data from Gauteng:


The >60 year old category there definitely shows a much lower drop-off.

From there the thread pivots into what’s happening to hospitals, including reference to this additional thread on that. I’ll cover that in the next section. That other thread does refer to severity in elderly patients, and finds it substantially improved:

It then pivots back.


The log scale on the right means that it’s the gap between the lines we should pay most attention to, and it clearly does indicate good news.

Similarly, this thread is on the situation in the hospitals and draws clear contrasts of those boosted, those vaccinated but not boosted, and the unvaccinated.


Our hospitals in many places were already under severe strain due to Delta. Now there’s a shortage of staff due to illness, and lots of Omicron patients showing up. Those patients mostly aren’t landing in the ICU, but the situation remains under tremendous strain on both sides of the pond.


UK hasn’t lowered their isolation requirements yet, which is compounding the problem there.

Backlogs persisting for months is entirely consistent with my model of the dynamics here. We never got our slack back from when we gave it up, because that would mean giving up permanently on patients.

Here’s the summary from the linked thread above.

This seems right. Hospitals are in a bad way but holding. The scary scenario is if cases among the elderly are only now picking up and severity is much less reduced in that group while also starting out at a higher level, and things then get much worse. Cases are accelerating full blast and will peak very soon in the first-hit areas like New York and London if they haven’t already, but it will take another cycle or two before the effective risks start declining.

Hopson then had another updated thread on 3 January, which gives more hope that the scenario can be handled. Situation continues, and the problems in London are being seen elsewhere as well, but London isn’t getting that much worse.

The news is good. The center is holding:

It’s not over yet, and it’s going to get worse before it gets better. Similar story from Philadelphia (see full thread for more details).

If I needed a test, and didn’t have much in the way of symptoms, I’d stay the hell away from the ER right now. That seems like a very good way for you to test negative today and then get your symptoms two or three days later. We need to do better warning essentially healthy people to keep their distance, not only for the system’s sake but for their own. This also seems like an excellent prescription if we are capable of doing it:

Link to that article. A lot of this is much worse due to a failure of professionals to talk logistics. I’m guilty of this too, in the sense that I don’t focus on forward-looking logistics often enough. Long term I need to remember to talk logistics more. After all, as Hunter S. Thompson pointed out, when the going gets weird, the weird turn pro.


There’s a lot of population in the red and yellow areas here, but it’s not about whether you go over, it’s about how far you go over, and how bad the consequences will be for how long.

Here’s a thread about the situation in New York City. A lot of similar observations. I’m worried about this observation, which is the flip side to other places where it’s proving logistically difficult to administer care due to the need to avoid it:

Overall, same patterns.

Given how much downside risk there was initially, I’ll take this level of pressure.

It’s going to suck, a lot. But it looks like we’ll mostly make it through. If it was going to be a complete collapse, we would know by now.


Could we be looking at the Pi variant in France? This reply convincingly says no, this one is less kind, this isn’t new and if it had anything like Omicron’s infectiousness then we would know. Level of concern here very low.

This is what the quarantine looks like in Xi’an, where you’re not allowed to go outside for any reason so you’re dependent on government food deliveries, and they disinfect the streets anyway. This seems like Maximum Containment and it’s at best going to be close. This doesn’t seem sustainable.

Zeynep thread pointing out that exponential math eventually causes massive disruptions no matter what, in context of NYC.

Gottlieb predicts the wave will take two months, that NYC will peak within two weeks, most other areas within four weeks. If anything I expect it to be faster.

The question is how much more exponential growth is left before it’s over, and how much we should be focused on the hospitalization number versus the ICU number (because potentially we have a ton of people ‘with Covid’ instead of being there ‘for Covid.’)

Thread calling for more effort to slow spread on the basis of ‘millions being crippled by Long Covid’ and claiming that getting Covid now makes you more susceptible in the future by ‘creating pre-existing conditions.’ This is very much not my view, but if I did believe that Long Covid was this bad, the rest would indeed follow. I don’t see any evidence cited here that would cause me to update on my view of Long Covid.

Prediction Updates

Adding this, from Nate Silver (here’s Metaculus):

I hope soon to be able to expand my work with prediction markets, and also we’ll have everyone’s 2022 predictions to play off. Going to be a fun ride.

Will There Be a Federal Mask Requirement on Domestic Flights as of November 8, 2022? %? → 50%.

Metaculus has the median for lifting this requirement in August, which roughly agrees with Nate. I’m more optimistic about not needing a mask mandate on planes, but also more skeptical that it will get lifted. Is your tray table up and your seatbelt in the full upright position? Have you met the TSA and their machines that they assure us no longer cause cancer (and that I still opt out of)?

Since this is a slow-moving one, I will only update it every so often. If you’re curious where I’m at, you can give me a nudge, but this should stay roughly here for a while.

Chance that Omicron has a 100% or bigger transmission advantage in practice versus Delta: 60% → 55%.

I messed up the math last time and said 70% before adjusting to 60%, but our starting point this week is 60%. On reflection, after adjusting for early advantage and looking at when things are stabilizing, my guess is that this is going to be close, and we may never know for sure.

Chance that Omicron is importantly (25%+ in the same person) less virulent than Delta: 85% → 90%.

Chance that Omicron is vastly (75%+ in the same person) less virulent than Delta: 20% → 25%.

The news out of the hospitals seems clear. Unless something very strange is happening, Omicron is substantially more mild than Delta. I don’t expect us to hit the 75% threshold, but the news keeps being good on that front, so for now I’m creeping a bit higher.

Chance we will be getting boosters modified for Omicron within 6 months of our previous booster shot: 20% → 20%.

Israel is going with their fourth shot, but otherwise things seem to be settling into full complacency. I didn’t define who ‘we’ is here, but I meant the broad ‘we’ as in I personally have the legal option to get one, I’ll be 43 years old and technically have a risk condition but am not immunocompromised. Note that even if I’m allowed to get one, I don’t intend to get one if the peak has already passed.

Chance we are broadly looking at a future crisis situation with widely overwhelmed American hospitals, new large American lockdowns and things like that: 10% → 5%.

We’ve made our position clear. It’s going to be difficult to get care of any kind for a month, but we’ve picked ‘muddle through’ and we’re sticking to it.

Generation time (serial interval) of Omicron is 3.5 days or less: 85% → 87%.

This continues to be the best fit of the data and I’m creeping the number up a bit, but my guess is we will never find out for sure (unless it’s super not close) because experimentation remains illegal.

Daily cases in the the United States have peaked by February 1, 2022: ?% → 85%.

This seems like more than enough time to be on our way back down, but you can sustain a lot of cases for a long time. Feels right to express my degree of certainty about this. I’m curious how confident other people are on this.

I’ll open the floor to suggestions. What would be the most high-value things to put in the predictions section at this point? Links to Metaculus are always a bonus, or better yet real-money prediction markets. Mostly I plan to wait until I see the other 2022 prediction threads, and play off of those, like I have in the past.

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66 Responses to Omicron Post #12

  1. Dave says:

    Delgado’s observation about the correlation with boosts is good news of course. But it’s worth noting a couple of selection effects/confounders:
    –Not that many people have had boosters
    –Those who have had boosters are no doubt more likely than average to behave carefully

  2. Cherry says:

    1. Zvi, do you have any thoughts on the excess non-Covid deaths in the 18-64 group…

    2. …Israel offering fourth doses…

    3. …the introduction of short health passes/Covid-19 passports (4-9 months)…

    4. …and the possibility that we may practically forget about the pandemic in summer 2022, resuming normal lives?

    BTW, I know you’re past the point of arguing against the significance of vaccine-related myocarditis risk in young males, but at the emotional level, I can’t get over my concern about many isolated datapoints, like my friends feeling very, very bad after the booster shots, NYT citing concerns about multiple boosters (, or the number of sudden deaths of football players in 2021 ( :(

    • lunashields says:

      Of the things above, I’ve looked at footballers thingy, and it’s hugely bs. For prior years they get the data from wiki, where it says right there “selected deaths list”, with an unknown selection criteria. For the last year, they “collected news articles”. So selection criteria is hugely different.

      On top of it, to check the baseline, nih study (in the past) on sudden death showed 11.5 per 100k, not 4 as claimed. And nih study was on college age players, so expanding it to fifa (who’s all the way to 40’s) would bump it to at least 15, which is perfectly within normal variation from claimed 20 for 2021.

      On top on top of it, guess what else happened in 2021, besides vaccines for covid? Covid itself. Which is known, to say mildly, to have cardiac complications.

      • Lysimachus says:

        “On top on top of it, guess what else happened in 2021, besides vaccines for covid? Covid itself. Which is known, to say mildly, to have cardiac complications.”

        Yes, but Covid was there for the whole of 2020, yet the reported spike of cardiac problems among footballers (if the data is correct) did not happen then, even though many players were infected in 2020. It happened only in 2021, when the vaccines were introduced. Given the amounf of censorship on the issue of vaccines, it might well be that the information about true scope of the myocarditis problems after Covid vaccines is being suppressed.

      • lunashields says:

        Hilarious how out of 4 points you nitpick on one which is the least consequential of them all. Nice debate skills.

      • lunashields says:

        And covid was here for the whole 2020? Really? It didn’t really start in march in some places? And the end of 2020 pretty much everyone had it, and it was what, gone in 2021?

      • lunashields says:

        Not to mention, that in 2020 most of the places where fifa played football were under lockdowns, so players didn’t die on the field, because… They didn’t play on the field. Some games restarted mid-fall or so.

        • Lysimachus says:

          “Hilarious how out of 4 points you nitpick on one which is the least consequential of them all. Nice debate skills.”

          I addressed the part I disagree with, on the other points you might well be right, although a study with proper methodology would be necessary to get a conclusion.

          “And covid was here for the whole 2020? Really? It didn’t really start in march in some places? And the end of 2020 pretty much everyone had it, and it was what, gone in 2021?”

          No, the point is that it appears that according to the collected data (whether their quality is sufficient or not) in 2020 there was no spike in cardiac arrests and deaths among footballers, despite the fact that Covid was already everywhere and many footballers go infected (there was real avalanche of cases, even in top leagues). This spike, according to the data, emerged in 2021, therefore it is reasonable to investigate at the possibility that it might be caused by vaccines rather than Covid. I am not saying it is necessarily so, but at this stage such a possibility cannot be ruled out.

          “Not to mention, that in 2020 most of the places where fifa played football were under lockdowns, so players didn’t die on the field, because… They didn’t play on the field. Some games restarted mid-fall or so.”

          Actually, in Europe the leagues (albeit not all of them) were restarted in summer already.

    • Yellowface Anon says:

      I expect vaccine passports to be renewed only on the condition of periodic revaccination, even if your antibody levels are sufficient against infection or hospitalization. We’re looking at rent-seeking instead of serious medicine and avoiding over-vaccination or snowballing adverse side-effects.

    • Yellowface Anon says:

      For 4, it is practically nil, not in a few years. COVID’s going endemic. At best it will be some background noise akin to climate change, and some sets of restrictions will remain that create new social divides, as if the existing ones aren’t unjust enough. You need to plan out these few years based on how much you want to engage with the whole biopolitical regime.

    • RM says:

      Someone asked me to look at the Indiana life insurance study. It’s being pushed on Twitter to claim there are huge numbers of excess deaths from vaccines.

      I don’t think it checks out, there are no excess deaths in the control group — countries like Australia or New Zealand, which had high vaccination rates but low covid rates:
      View at

      You can also look at it state by state, in the US. States that largely avoided covid (i.e. Hawaii or Vermont) made it through the pandemic with few excess deaths. States with high covid levels saw waves of excess deaths as covid came and went.

      This is not to say that the shots or boosters are completely safe. I don’t know that and can’t prove that. I can say they are not causing large waves of deaths among young people.

      • TheZvi says:

        Study seems fine, it’s measuring something else – I assumed from the start that the claim was ‘Covid makes you sicker even if you don’t die from it directly’ and perhaps some of ‘our lifestyle adaptations cause us to be inactive and anti-social, and thus are not good for us.’

  3. mfeingol says:

    > Note that even if I’m allowed to get one, I don’t intend to get one if the peak has already passed.

    • TheZvi says:

      Risk after the first booster will be minimal once the hospitals are fine, given my health, so I’m guessing it’s not necessary.

      • Fermion says:

        We haven’t talked much about vaccine risks, is it the potential problems of hindering our immune system with too many doses (original antigenic sin? the supposed maximum of mRNA vaccinations? unknowns?), or the rare or non-rare side effects that you would think about with the 4th dose?

        If you don’t want to discuss this I understand, I see that this discussion could be potentially net-negative at the moment.

      • mfeingol says:

        What if Omicron persists at a similar level to Delta pre-Omicron? Seems like cost/benefit analysis would suggest taking the Omicron-specific shot?

      • TheZvi says:

        I don’t think that’s how sin works here, extra doses won’t make things any worse there (if I understand correctly).

        If Omicron is at Delta levels permanently then it would be at least close? But my guess is that’s not enough.

    • Yellowface Anon says:

      What if your vaccine passport is revoked over this decision, Zvi?

      • Yellowface Anon says:

        I mean, not revoked, but not renewed either. It appears to be the design of some systems like the EU and Israel ones.

      • Yellowface Anon says:

        I don’t mean it being revoked, but set to expire after some semi-arbitrary period like 6 months, which is the design of some systems like the EU and Israel ones.

        One set of people I can expect joining in social alienation with the unvaccinated is those who feel they are well-vaccinated enough, yet the vaccine passport system is telling them you need to be continuously revaccinated to maintain your status. This is an administrative decision instead of a personal health one.

      • Yellowface Anon says:

        (delete my shorter reply please, I didn’t see it posted when I typed the longer one)

      • TheZvi says:

        I don’t expect it to be required in a world where I actively don’t want it, but if this does happens, fine, I’ll get it, who cares, seriously not that big a deal.

      • Yellowface Anon says:

        I wish I can edit comments in WordPress.

  4. Basil Marte says:

    Prediction question: will the NY governor’s executive order to postpone elective surgeries be lifted (or outright reversed) on/by the Jan. 15 revision date? Given the good chance for case numbers (but not hospitalizations) to have turned the peak.

    Unrelated indicator of thinking clarity: Hungarian news have, after reporting on the previous day that “flurona” (simultaneous infection with covid and flu) is a thing (having been detected in Israel), reported that flurona has arrived [sic!] in Hungary.

  5. Mike says:

    If I’ve previously had covid, how much benefit to the vaccines? Previous exposure feels slightly more protective than standard 2 doses, but maybe less than 2 + booster. So is this a question of benefit of booster vs. no booster? (Under 50 & very healthy)

  6. Graham Blake says:

    The one conceivable way that negative apparent effectiveness of vaccines is a “real” thing is if prior infection provides stronger protection against Omicron than vaccination, and is not properly controlled for. I think that’s an open question. I am having trouble finding compelling data on this question that’s more current than the first week of December. It’s plausible anyway that prior infection gives the immune system more to chew on than vaccination, and more of that is pertinent to Omicron than what the vaccine mimics.

    Of course, while negative apparent effectiveness may be “real” when treating the unvaccinated as one population, that is most definitely not a single population. (Not that it ever was, but pre-Omicron the vaccination advantage was so significant that you could treat it like a single population and still demonstrate >80% VE.) Also, whatever the apparent effectiveness advantage of prior infection, it is also perhaps the most perfect example of survivorship bias one can devise. So sure, maybe prior infection does confer an advantage over vaccination, assuming you’re not already dead. Of course, I guess death is 100% effective against Omicron too.

  7. Econymous says:

    Scott Alexander has expressed his disappointment with the questions PredictIt chooses elsewhere, and I am pretty much in the same boat. Has there been any effort to try to engage with them to get some better real-money prediction markets spun up? I wonder if they’d be receptive to receiving questions from you or others.

    Seems like they ought to, since they make a hefty chunk on every transaction… more markets in which people are interested seems like an easy win for them.

    • TheZvi says:

      In theory they should post whatever we ask for, within their guidelines. In practice, we don’t have a contact point, but I could actually try to find one and I haven’t.

  8. Econymous says:

    Is there a reason to expect that exposure to the virus that does not result in an infection provides an immunity boost? For example, if I get COVID, recover, and spend the next several months being repeatedly exposed, am I better-protected in the long run than if I get COVID, recover, and isolate for the same amount of time?

    Similarly for vaccination – is it possible that being less conservative post-vaccination would result in immunity waning more slowly or less significantly?

    • TheZvi says:

      The reaction in those cases isn’t widespread enough, it doesn’t create memory in the right way, is I think the basic reason.

      • Brett Bellmore says:

        My understanding is that, once you DO have that memory, any subsequent exposure to the pathogen in question temporarily spikes your antibody levels. So chronic exposure to covid after having gotten over it, or having been vaccinated, should keep the levels high.

      • Econymous says:

        I was under a similar impression, but I could certainly be wrong. Anecdotally, I happened to have a chickenpox titer right after my girlfriend had shingles, and the nurse remarked at my much higher-than-expected antibody levels.

  9. MPD says:

    Some thoughs and questions: Omicron is contagious enough that it I don’t foresee it ever going away and immune evasive enough that previous infection and vaccines merely reduce symptoms to a ‘safe’ level. Considering the gradual reduction in immunity over time, I wonder what timeframe people are expecting between subsequent infections with the same strain. By the time a year rolls around, is everyone who got sick this year essentially fair game for the virus again? Is what we are seeing this winter going to be the new normal for winters going forward? Does an omicron specific booster have a reasonable shot at shutting it down long term?

    I am not knowledgable on how immune evasion works and would love to get some thoughts about why I should be pessimistic or optimistic about the Covid forecast for this time next year.

    • Lambert says:

      Depending on the strength of seasonality and rate of immunity loss over time, it’s plausible that we might see a wave like clockwork every winter or small spikes most years with a bigger wave every 3 or 4 winters or entirely chaotic behaviour.

    • RM says:

      No one knows, for this virus. But here’s the best study I know of, regarding the other 4 endemic human coronaviruses. Immunity only lasts about a year for those. The average person gets reinfected every few years:

  10. Ninety-Three says:

    I don’t know if this is something where a prediction market can be expected to yield useful insight, but supposing it can a high value question is definitely something to the effect of “Will there be another variant that takes over and is X% worse than Omicron?”

  11. Nick H says:

    So because the Danish study didn’t turn up the result you expected, you just… disregard it? Not seeing any real attempt to engage with what the flaws might be.

  12. Zviposter says:

    What are your thoughts on the recent #SwabYourThroat phenomenon? Specifically how rapid tests sometimes give false negatives when only the nose is swabbed, but adding the throat swab reveals the true positive:

    • TheZvi says:

      Not sure, but it’s plausibly helpful. Haven’t seen a good source yet.

    • Triskele says:

      Michael Mina says ‘maybe’, in response to the same tweet.

  13. Re “high value” prediction questions linked to real-money markets, how about case numbers? Polymarket has a market going on that:
    Meanwhile, Kalshi has a largest daily case numbers market ( They also have an Omicron specific vaccine market ( and a VOHC market (

  14. ech says:

    A relative is an ER nurse in New Orleans. She said that they are overwhelmed with people coming in for testing. At one point the wait for a test was 22 hours. The parish health officials are begging people to not come to ERs for testing.

    The Texas Medical Center in Houston (largest health care complex in the US) is below capacity in the ICUs as of a few days ago, about 18% of ICU beds have COVID positive patients. ICU at 90% capacity, which is low, they generally run 95% or more. There is substantial surge capacity there.
    Status here, updated weekly:

  15. Large negative effectiveness is not a thing, we would know about it and the world would look very different

    In general it is most definitely a thing. Negative efficacy means: there were worse conditions in the treatment arm compared to the control arm, i.e., the treatment was actually harmful.

    Let pT and pC be the probability of infection/hosptialization/death (whatever endpoint you’re measuring) in the treatment and control arms, respectively. Then the efficacy is defined as the fraction of the amount of risk in the control arm that you reduce:

    E = (pCpT) / pC = 1 – pT / pC

    (There are more subtle versions of this using Cox regression and hazard ratios, but those are basically like this, but with ways to handle trial dropouts and to stratify by subgroups.)

    There are 3 broad regimes, depending on the sign of E (modulo its confidence limits):

    (1) If E > 0, then the treatment arm experienced less risk than control. This is what we want.

    (2) If E ~ 0 more or less, then there is no effect. Too bad, but it happens a lot.

    (3) If E < 0, then the treatment arm experienced more risk, i.e., was actually harmed. Big red flag! In fact, E can go to -Inf if there is finite risk in the treatment group, but the control group risk goes to 0.

    Relevant real-world example from the molnupiravir trial:

    (a) The first half of the patients had hosptialzation efficacy 48.3% (CL: 20.4% – 66.5%).

    (b) The second half had hospitalization efficacy of -32.5% (CL: -151.6% – 30.1%). In this subset of patients, there were 20 hospitalizations in the treatment arm vs 15 in the control arm.

    From +48% efficacy to -32% efficacy in the same trial?! You can see why the AMDAC members were uneasy, describing the efficacy as “wobbly”. (And thanks again to commenter Thomas here for making me work through the details on this example.)

    Now perhaps you were making a different point: that given the previously seen huge positive vaccine efficacies from clinical trials and from absolutely ginormous numbers of vaccinees since authorization make negative vaccine efficacy here very very improbable. That’s most definitely true. It sounds like something is hinky in the study. (I dunno why it got published either; people don’t normally publish papers that say, “Hey, here’s a puzzle: can anybody figure out what’s wrong with our data?” World might be better if we did that, clearly labelled.)

    So if that was your point, then I endorse it and apologize for being such a fuss-budget about the math of vaccine efficacy. :-)

    • Ah. Here we go: commenter lkbm pointed above to a tweet from Hansen, one of the study’s lead authors.

      If you dig in a bit, Hansen points out at least 3 sampling biases, more or less unavoidable, that make the vaccine look worse than it is for early Omicron in Denmark. Summarizing what he said:

      (1) Apparently in Denmark testing is more frequent for vaxed than unvaxed people, so cases are uncovered among the vaxed more often. (The Twitter commentariat gave some pushback, but let’s take Hansen at his word on his own country.) Thus cases would be seen among the vaxed more often, because of relative undertesting of the unvaxed.

      (2) Denmark did a lot of sequencing. In the early days of Omicron, the cases were mostly among international travellers, who under travel restrictions tended to be professionals. Professionals, the early Omicron cases, were more likely vaccinated, so that’s another Omicron linkage to vaccination.

      (3) A basic assumption is that vaxed and unvaxed people behave similarly; Hansen asserts that in Denmark the remaining unvaxed people behave more cautiously because they’re unprotected. (Seems the opposite in the US, where vax resisters also resist masks, though.) So if the vaxed take more risks, more Omicron shows up there.

      This is all post hoc, but has an air of plausibility especially since the authors themselves come forward with it.

    • A1987dM says:

      He said “we would know about it and the world would look very different” not “it’s mathematically impossible”…

  16. Donald Duck says:

    Zvi, how much sense does it make now to disinfect groceries and parcels with a diluted detergent given omicron’s higher infectiousness? I really want to avoid the infection, and I can’t ensure that all people in my household (e.g. kids, elderly) will scrupulously wash their hands each time they touch things.

  17. Donald Fagen says:

    I miss the Zvi of October! There is a war, and you have switched back to the side of Insanity.

    Things I fear:

    1. There will always be a plausible enough short term justification for pandemic restrictions. Unfortunately, this leads to long term restrictions.

    2. If you ask a doctor or nurse if they are maximally busy, they will always say yes. I think it’s part of the job profile to claim to have absolutely zero spare capacity. What we are doing with the hospital system is just asking a lot of doctors and nurses this at once. Of course they will always claim to be ‘this close’ to collapsing.

    3. We are actually at risk of creating a self inflicted major staffing crisis in healthcare (and in the economy as a whole). We have made the jobs stressful and terrible through ostensible Infection Control Measures. We have everyone unable to work due to mild omicron colds. I fear a major surprising collapse.

    And of course it will be used if it comes to say ‘we should have overreacted more.’

    • TheZvi says:

      I notice I am confused what particular insanity you believe I am advocating.

      I’m saying explicitly that I expect the hospitals to NOT collapse, and have not called for any measures to deal with that other than agreeing that we needed to shorten isolation periods? Is it that I’m saying (when possible) that we should test people before they head back to work?

    • Basil Marte says:

      Patients who are in a hospital for something other than covid are largely sampled from the least healthy part of the population, thus protecting them from covid is unusually efficient in terms of averting covid deaths per unit of covid-prevention effort. Of course, this assumes that the patients mostly wouldn’t have died from whatever non-covid thing landed them in hospital in the first place (including that the covid-prevention measures don’t interfere with care), that the covid-prevention measures passed are sane, that there isn’t a steep cliff where the marginal efficacy of prevention drops sharply, etc. Thus not having (+) staff care for (-) patients is IMO a good policy. Now, if there should be an actual staffing shortage, my first idea would be to “split the hospital lengthwise” to a (+) and (-) half, because even infectiously (+) (but not otherwise incapacitated) staff can be called in to care for (+) patients without causing harm.

      Alternatively, do you fear staff leaving healthcare altogether in favor of another career?

  18. jayeff says:

    So as someone who just got over Omicron, how long can I expect immunity to last barring a new variant? 2x Pfizer with a Moderna boost. Case was flu-like. If any of that matters.

    How about my 4 year old, who also got it?

    Looking forward to letting the young one do a lot more, hopefully.

    • TheZvi says:

      Unknown how long for Full Complete Immunity, but if Omicron remains the dominant strain than any reinfections either of you get will almost certainly be mild. I would act as if Covid didn’t exist.

  19. BTW, if anybody’s interested in the complexities of manufacturing the 2 compounds that make up paxlovid, Derek Lowe wrote a nice summary at In the Pipeline.

    Summary: It’s really hard. Also, the scale is daunting: 10 million courses means you’re committing to making, packaging and delivering 15,000 kilograms. Many of the inputs to the process are foreign-sourced, usually from China and sometimes just 1 or 2 suppliers worldwide, so you’re back at the mercy of the global supply chain. Just saying we can make it in lots of countries doesn’t mean they can all get the supplies they need to do so.

    Don’t expect lavish supplied immediately, multiple manufacturers or no.

  20. Yellowface Anon says:

    OOT, but I’m frustrated by this and can’t find a sympathetic outlet for this half-essay. I was going to explain my throwaway comment on Scott Alexander’s review of “Don’t Look Up”. It goes like this: “Some conspiracy theories aren’t on some random wacko’s page, but the website of the World Economic Forum.” And then Scott Alexander blocked me. Mmmmm.

    Here is my intended explanation in full:

    No, I’m not some dumb illiterate type who goes the other way the consensus currently lies. I’m only going to say a primer of what a smart subset of conspiracy theorists believe, that are substantiated by official pronouncements, because my thought process is much messier than the rationalists.

    Here it goes: COVID is indeed a pandemic, but it was lab leaked, likely intentionally. There was a simulation that approximated the outcomes of a disruptive global pandemic, months before the initial Wuhan outbreak. It was co-hosted by the World Economic Forum. The same institution has proposed, in “response” to COVID, the Great Reset. Now, it is for the reader to judge whether their initiatives are altruistic or selfish, but above all, they are an elitist institution, they have connections and participation of major international bodies, and they have taken as of late an accelerationist standpoint, especially on digitalization and 4th Industrial Revolution (mass AI-driven automation). All the wildest claims conspiracy theorists make of the WEF, from UBI/currency resets to degrowth/deindustrialization to depopulation, are corollaries to this core agenda. Some of their writings aren’t that different from passages taken from Brave New World or a tinfoil establishment-hating crackpot. You can search on their site and read their predictions yourself.

    The vaccine itself isn’t made with any sinister intent. There might be the usual effects picked up by the antivaxx, but they are incidental to what is at stake, or as the antivaxx say, intrinsic to vaccine production itself. It is the vaccine mandates and vaccine passports that are contentious – they create a captive market for rent-seeking Big Pharma producers while enabling a heightened level of regular surveillance and micromanagement. There is no coincidence that the social credit system in China is nearly established at a similar point in time. Similarly, lockdowns is a process of denormalization that allows new modes of social existence facilitating the digitalized, automated economy to be accepted on a mass scale, while severely curtailing social and economic rights of most, or a part of the population whose priors are at odds with the consensus. It is, in other words, a power grab.

    Whether any of this is correct depends on your worldview, but many, if not most, conspiracy theorists are able to construct a large coherent narrative like the one above, that is apparently supported by evidence available to them. Ditto for Global Warming. Opponents of the Global Warming narrative take satellite temperature datasets, apply adjustments based on a set of assumptions they deem just, and found out the official series systematically understate past temperatures. It is therefore naive and simplistic to depict conspiracy theories as typically rudimentary. They are as likely to be true, if not even more so after a review of the evidence, as the “official” establishment-sanctioned narrative and often arrived from a scientific or philosophical basis, the COVID response/agenda in mind. Conspiracy theories aren’t symptoms of barbaric discourses, but counter-elite discourses. This explains why some conspiracy theorists also hold political philosophies that are anti-hegemonic, like Neo-Reactionary/Marxism/Libertarianism.

    Sometimes, the elite narrative is close to the truth, or is more utilitarian. Sometimes the counter-elite narrative reveals some fact concealed by the mainstream narrative or some proper moral consideration that is brushed over. Of course they contradict each other, because they are locked in a contest for hearts and minds. What determines which narrative has the upper hand, is a question of power – Who controls the WHO? Who’s backing the agitation against all those COVID restrictions? It is inherently political. It’s also simple: which place gets all the attention, Davos or Florida? As political fortunes shift, as Trump quits the WHO and Biden rejoins, as the central bank muddle thru their operations and the next antivaxxer drop out of the gatekeeping system, as China locks down another city and stock up strategic supplies, as the calendar edges closer to 2030, the battle lines are being drawn.

    Fascists and Communists knew this and Liberals are going to learn it the hard way. There isn’t a narrative that is value-neutral, as Liberals like to pretend Liberalism to be. Nor that values matter in the survival of an narrative. Superstitions and those consolidating a power structure wins, in the end. We live in the Gotterdammerung. We have the post-Modern battle of worldviews, a genuine Cultural War. Having some nuanced view is good for principles, and it is certainly the ideal, but you will be trampled on by the ground troops of both sides. Pick the side you will maximize your survival on

    I definitely have to apologize for occupying this space for this. I largely agree with his post but I need to defend a narrative I partly sympathize with. And since I’m non-rationalist with an infinitely diminished mind that has gone worse from reading Alt Right info sources, There must be holes in my thinking and I’ll be thankful if you can supply the appropriate rationalist terminology for some of the concepts I arrive at in the above. (Should I post this on LessWrong even if the thinking and conclusion are explicitly a-rational?)

    • TheZvi says:

      Understood. I’ll let it stand here this time given the circumstances, but I do strive to avoid such matters, so please don’t make it a habit. If nothing else, you can always start your own blog on either WP or SS.

  21. J says:

    > Chance that Omicron has a 100% or bigger transmission advantage in practice versus Delta: 60% → 55%.

    How does this square with the sky-high infection rates we’re seeing? Is the idea that, say, it’s only 90% more transmissible, but that’s enough to produce the effects we see?

    I suppose shortened transmission interval gives us a wave in fast-motion, but seems like the peak of that wave should be at the same amplitude (we’re just compressing the time axis).

  22. Justin says:

    Hey Zvi, thanks so much for all the detailed posts!

    You’ve mentioned this in passing, but I’m curious to what extent you think the current volume of hospitalizations, and to a lesser extent deaths, are due to the “with COVID” vs. “for COVID” distinction. Back in the early days of the pandemic, my conservative relatives kept bringing up these weird cases where someone died in a car crash and it was reported as a “COVID death” because they tested positive. My guess is that this sort of thing is probably more relevant right now, because COVID is statistically less deadly than before due to vaccination/immunity/better treatment/Omicron, and infections are extremely widespread. It seems like some but not all jurisdictions make this distinction, and it’s hard to get a sense of how important it is when assessing the situation overall.

  23. myst_05 says:

    > Will There Be a Federal Mask Requirement on Domestic Flights as of November 8, 2022? %? → 50%.

    I think that’s overly optimistic. Masks could only go away if:

    1. There’s a massive shift in attitude to COVID in the Democratic party and Biden is pressured to remove mask rules. I’m not sure if this can happen so soon.
    2. Democrats have a big loss in the midterms and are forced to remove masks in exchange for some other concessions. Possible but new Congress members won’t be sworn in until January 2023.
    3. The current legislators use masks as a bargaining chip to push a reform. Possible but I haven’t seen this brought up in the media and it doesn’t seem like Republicans are actively demanding this.
    4. A Republican President wins in 2024 and abolishes masks. We’d then see them gone on January 20th 2025 at the earliest.
    5. There’s significant travel disruptions due to maskless travelers, to the point where masking rules are removed defacto or dejure, similar to how masking enforcement is defacto gone in retail stores. Not sure what would trigger this now, given that this didn’t happen earlier in the pandemic. But in any case the legal requirement would remain in place.

    So my prediction for Nov 8 2022 is 20%. 50% by November 2023. 95% by March 2025.

  24. Yellowface Anon says:

    What happened in Israel, the mass revocation of vaccine passports due to skipping booster shots, can and likely will happen in America. Ditto for Omicron-specific boosters even if it is poorly justified given the observed virulence levels. We might be looking at the tightening of the screws, first sifting the unvaccinated away, and then those who don’t see the point of boosting, and then those who deem Omicron-specific boosters unnecessary. What about those who are temporarily ineligible for Omicron boosters because they’ve been recently boosted with regular vaccines, if in the <20% chance that Omicron boosters are made and mandated? Are they trapped in limbo?

    This isn't the way to use vaccine passports as a "gateway to normalcy" if you keep an increasing portion of people in the dark, with a decent chance of those staying inside being kicked out of the system. I can't stress it enough since the system has a decent chance of entrenching itself, and my conspiracy theorist instincts tells me it will become exclusionary for decidedly non-public health ends.

    • Graham Blake says:

      I just don’t see the unvaccinated or undervaccinated or incorrectly-vaccinated as so interesting a class of people that there is any structural advantage for anyone to exclude that class of people from ordinary activity for no objective public health reason. What is the motive? For sure if this kind of disenfranchisement played out as literal disenfranchisement, so that the unvaccinated were unable to vote, this would be “exclusionary for decidedly non-public health ends”. I put the chances of that happening at approximately zero. It is very hard for me to see any nefarious non-public health reason to keep the unvaccinated class from going to pubs, or getting jobs working in long term care facilities. Who stands to gain by hamstringing the economy and excluding that specific class of people? Big Pharma? In order to have 85% or 90% of the population taking boosters instead of 80% they are going to orchestrate a behind-the-scenes secret policy coup like this? Instead of simply filling their pockets up with the cash money the most willing 80% provides?

      The inherent problem with this sort of conspiratorial thinking is that it inevitably leads us to focusing on imaginary or purely speculative problems when equally or more serious problems are happening in plain view right under our noses. Probably the worst case scenario one can imagine from someone maliciously leveraging vaccine mandates and passports is the unvaccinated class becoming disenfranchised from voting. Meanwhile, politicians are regularly attempting to change voting laws and gerrymander in order to more efficiently disenfranchise specific classes of voters, and doing it in plain view all the time. How much do you worry about that? If it’s less than you worry about nefarious vaccine policy ends, then I’d suggest you’ve thought yourself into an intellectual cul-de-sac.

      There are a whole host of reasons that we should want public health officials to back off NPIs as soon as it is practical to do so. We don’t really need to invoke shadowy conspiracy theories to frighten ourselves into considering vital. No doubt public health officials will continue to err on the side of too many NPIs rather than too few. (And I guarantee there’s more economic benefit to the powerful through ending NPIs than there is in prolonging them.) In many jurisdictions – arguably the ones we are primarily talking about – there is a higher cost for public health officials in having too few NPIs rather than too many. This is just how the incentives are aligned for those roles. Better to be accused of being too cautious than be accused of killing grandma. A reluctance to back off NPIs can more than adequately be attributed to that rather than villains twirling mustaches behind the scenes. We need public health officials to see, as expediently and as widely as possible, that it is in fact in their best interest to eliminate public health measures that are no longer necessary to protect the health care system. When the next pandemic comes, they will have way more credibility if they don’t prolong our collective nightmare beyond what was reasonably necessary to protect the health care system. Hopefully what Omicron will prove is that our health care systems are no longer under threat, and we can start moving on in earnest.

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