Prediction responses (no strong outside view reasons to think I'm right here):

China keeps cases contained: sell to 30%. Their pulling out all the stops has been barely enough before, I expect even China to have lockdown fatigue and I generally expect Chinese government action to be less competent than e.g. Korea or Singapore.

Median/mode us cases - I think about right? But I've noticed I have a bias to expect things to peak earlier than they do, so I'd take the over on this one, probably not more than a day or two.

Mask mandate for flights: buy to 65%. Air travel truly loves imposing annoying requirements.

Omicron boosters: sell to 7%. I've been under on this throughout, and most of the updates have been on the down direction.

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China's (only partially exhausted) tools to control internal movement cuts in favor of containment.

The sheer size of everything in China cuts against.

Over a dozen cities with 7 million people. We know that city by city there is a lot of heterogeneity in outcomes, each large city is another lottery ticket for things to go poorly.

What if we see major outbreaks in 10% of provinces or large cities, with isolated to no cases elsewhere, is that contained or not contained? The stated threshold was 50 million. For that I think we need to say that the fate of Zhejiang determines the fate of Gansu, and I'm not sure that's necessarily true.

Cutting for: ruling class might feel that domestic vaccines make them especially vulnerable to quickly spreading variants, so they might put in panic level measures.

Cutting against: ruling class may view lower hospitalizations from omicron with relief and view this as the best likely time to dismount.

Cutting against: economic strains from continued property sector unwinding might limit political capital on lockdowns. If the party is maximally motivated by avoiding revolutions (probably oversimplistic), then now you have that danger on both sides, economic and health, so that will be a moderating force in political decisionmaking circles.

Complicated: If you don't believe data integrity in China, then you might think previous infections (and deaths among the most vulnerable) were much higher than reported, which will limit the impact of Omicron to some extent. This might be negligible though? How protective is sinovac + prior delta infection against omicron?

I do like your argument that they've tried hard before and barely made it, but overall I think this relies on too many hidden stakeholders who often creatively invent new powers. Buy to 35 sell to 60 for containment? Let me pause and calibrate with Taiwan.

For Taiwan, an infection of a quarantine taxi driver and at a quarantine hotel are bad signs:


Quarantine taxi drivers are almost entirely walled off from passengers. It represents something close to maximal effort at preventing transmission during inevitable proximity. As flights landing with omicron increase, due to its prevalence elsewhere and greater travel in advance of Chinese New Year... it's a cracked dam facing increasing loads.

Maybe test and trace internally holds up as a second line of defense somehow. They are the only place that has successfully fully extinguished covid before, that should count for something. 75% it's uncontained by March.

Hmm, why do my Taiwan and PRC predictions diverge so much...

Yeah, Chinese New Year is bad news in the PRC too, big internal migrations coming. That partly drove 2020. Based on that I'll sell to 25 China contains it, and will update with radical new confidence if they make it past February unscathed.

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Updating to only 5% either ROC or PRC keeps it contained now, I think it's all but decided at this point.

Much faster than I expected.

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The finding that saliva tests detect Omicron infectiousness several days before traditional nasal tests is quite interesting. I just went down a rabbit-hole on that, and it sounds like there may be room for the average person to act on this information without waiting for the FDA to officially authorize new testing protocols.

Some physicians and experts are suggesting that people swab the back of their throat before swabbing their nose when using traditional off-the-shelf rapid antigen tests.

Washington Post article about this: "Should you add a throat swab to your at-home covid test? Experts disagree."


EDIT: OK, I went way further down this rabbit-hole and wound up starting a Substack and writing a whole "Much More Than You Wanted To Know" about it. https://brunchateleven.substack.com/p/should-you-also-swab-your-throat

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I will give a 70% probability to China’s ability to contain the virus. 1) Chinese model of governance 2) extensive use of testing and Artificial Intelligence 3) Very serious and able Government 4) experience gained during these 2 years 5) knowledge

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I was with you until "Artificial Intelligence"

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Re: Japan

You're right that previous containment measures here have largely kept Omicron at bay, but the recent uptick is real and worrying. Basically, there are a bunch of US military bases on the island of Okinawa, and some bizarre rule allowed US personel to come to base without testing for covid. So naturally, they brought Omicron here from the US in droves, and now it's outbreaking on Okinawa HARD, including lots of community spread off-base.

Given that domestic flights between Okinawa and Tokyo/Osaka/etc are totally open and require no testing, I give it at most 1-2 weeks before we start seeing Omicron exploding on the main island of Japan as well.

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I'm going to predict a 10% chance that China contains omicron until 1 month after the Olympics finish on February 20.

I've been following Australia's efforts to defend our COVID zero position and I think this gives insight into the effects of lockdowns from a mostly COVID zero baseline. Outbreaks of Wuhan strain and Delta (from mostly zero case baselines) responded noticeably differently to lock-down measures and I think this points to the ceiling of what lock-downs can accomplish (lockdowns can sometimes contain delta, if the lock-down is extreme and committed).

Wuhan strain (R ~2.5) - lock-downs were successful every time (just)

In the March 2020 wave, Wuhan strain got into most major centres in Australia. Lock-down brought the entire country to COVID zero within a few months, and mostly kept it there until delta.

The exception was a much larger outbreak of Wuhan strain in Melbourne (2020 wave). This took a long time (111 days of lock-down) to get to zero and didn't spill into other parts of the country (due to strict state border restrictions).

Conclusion - Wuhan strain was consistently contained in Australia with strict lockdowns (police enforcement, curfew).

Delta (R ~5)

In mid-2021, from a baseline of zero community transmission, delta outbreaks occurred in Sydney, then Melbourne, then spilled over into a range of smaller cities around the country. Sydney tried to contain with lock-down but this was ultimately unsuccessful and the delta outbreak continues there. Melbourne locked down hard and early (day 1 of Melbourne lock-down was in response to 6 cases / day, and curfew was reinstated), and stayed locked down for months until it was clear the strategy had failed. Shorter lock-downs in other cities were more successful (Canberra, Brisbane, Darwin, Cairns, Perth etc.) and the rest of the country outside NSW, Victoria and ACT stayed at COVID zero until omicron.

Conclusion - Delta was noticeably more difficult to contain than Wuhan, and outbreaks in larger cities were not contained despite herculean efforts.

Omicron (R ~7.5)

No lock downs attempted in response to omicron in any major city, but the same story as other western countries - insanely exploding case numbers. Australia went from from COVID zero in most places, to omicron in virtually every community within 3 weeks. Now ~1% of Melbourne's and Sydney's population testing positive each day (similar to London and NYC 1-2 weeks ago).

If Delta was difficult to contain with lock-downs, then omicron will be virtually impossible.

Other points against containment:

- RATs and PCR tests are showing a lot of false negatives in the early course of illness - this makes a test and trace strategy at the Olympics even more difficult.

- Australia had a mandatory hotel quarantine program (until a few weeks ago)- 2 weeks in quarantine for every returned international traveler. Despite this, Wuhan and Delta got out to the community many times. A quarantine program where athletes are placed in a hotel room in isolation for 1-2 weeks is not politically feasible immediately prior to the Olympics.

Points in favor of containment

- China's successful (close to) COVID zero track record up until now.

But omicron is different, as above.

- China's willingness towards more authoritarian measures than Australia, New Zealand, Korea, Japan etc.

But welding people inside their apartments is not such a viable option, when the people in question are high-profile international sports people, and the world's spotlight is on you.

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Re. China containment – I would be extremely surprised if daily cases stay under 50p/m this year. I put it at 15%.

I think Australia's experience in 2021 is a reasonable (if imperfect) analogue here. For the first half of the year, it was completely intent on keeping cases at zero. With lockdowns, closed borders, and lots of restrictions, it was able to do this effectively. Then Delta arrived, and everything became much harder. Even with prolonged lockdowns, fairly good contact tracing, and stringent isolation requirements, cases continued to climb. By late August, it hit 50d/cpm (despite most of the country still having no community transmission), and has rarely dropped below since. I think this point is instructive because when Australia first hit 50d/cpm (Aug. 28), it was still very much pursuing something close to a zero-COVID approach; on that date, the lockdowns in Sydney and Melbourne still had another 43 and 54 days to run respectively. Once it became obvious that cases were never going back to zero, harsh restrictions became more difficult to justify, and most people accepted that some form of 'living with COVID' was the only viable approach. Now, Australia is at over 3,000d/cpm.

I expect Omicron to do to China what Delta did to Australia. China mostly managed to contain Delta (which, admittedly, I wouldn't have predicted), but Omicron raises the bar. Delta made everything harder – Omicron makes things near-impossible. Very roughly, I would say that the original COVID strain was a 3/10 to contain, Delta was a 6/10, and Omicron is a 9.5/10. Australia's zero-COVID dreams died at 6/10; I don't think that China's withstand 9.5. From what I've read – and on current form – it does seem likely that the Chinese population will continue to accept containment measures that would be unworkable almost anywhere else, and so that does add a little uncertainty. But even with the toughest of restrictions, I still struggle to see cases staying that low. 50d/cpm is only 70,000 daily cases, in a country that has 65 cities of 1m+ people.

That’s how I end up at 15%. I'm tempted to go even lower, but China is unique in a lot of ways, and I’ve been surprised by it before. Also, by terrifying its citizenry and mocking the West for its COVID-tolerance, the Chinese government has really backed itself into a corner on this. To lose control now would be incredibly embarrassing (particularly in the year of a Party Congress), and so I expect the CCP to do all it can to avoid an about-face.

But I’m not betting against Omicron here.

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It's worth noting that the CCP staked a strong claim to being superior to other governments on their ability to contain the virus they deny having made. Their 50-cent army of propagandists have been incessantly crowing about how great the CCP is for being able to effectively stamp out the virus that brought the mighty US down. There is a lot of face to be lost if this achievement was to fail in a visible way, and in China face is everything. And of course the CCP can also fake almost every number that comes out of China.

Given the above I would not be surprised if their currently low numbers were a stage of denial, when there is already enough Omicron going around but still low enough to pretend that containment works. At some point the mass infection wave might become impossible to hide but even then they might just stop testing and pretend it's just some sniffles, not the big bad Covid.

A lot of strange things can happen in China.

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Zvi, do you have any advice about what to do if you got the Johnson & Johnson shot (early last year)? I got a Moderna booster, but is there anything else I should do? I'm concerned I might not be very well protected. A friend of mine wants me to get a second booster, and basically pretend I never got the J&J.

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I would presume that you'd want a total of 3 shots with reasonable spacing between them, if you want booster-level protection.

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have you seen anything remotely recent on seroprevalence (US, NYC)?

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I haven't seen anything on this since Omicron came along. Curious if anyone else has seen anything.

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Is there any particular reason to NOT expect that immunity from omicron infection will considerably wane in a year? Imho if it wanes, we might be in similarly unpleasant situation next winter. Nothing as bad as previous year, but economic costs still totally horrific.

"Act as if everything is normal" is not a viable proposition when double digit percentages of a workforce are calling in sick (edit: at the same time). Is this something we should be preparing for next year, or better, preparing measures to avoid it?

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If most of the population has been infected previously, then even if that immunity wanes, those people will still get almost entirely mild cases, and they'd still be much less infectious. Potentially we'd have some issues if everyone continued to freak out like now, but if everyone kept their cool, it seems fine.

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Ok, that sounds good. I still have my doubts though. It very much depends on what "mild" will look like. Currently it is defined as anything that does not land you in a hospital.

If large fraction of "mild" cases in the next wave will be healthy people knocked out of work for a week or more, this is not ideal. "It will be like especially bad flu season, only worse" is not good news, imho.

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2 meta points on predictions:

Lack of markets on China containment: how hard would it be to run a polymarket on that, do you know? Maybe a series of month-horizon markets, for fast-resolution purposes? (Writing it up and locating a suitable source seems uncomplicated, but I have no idea about the human-level process that chooses which new markets happen.)

On the Omicron booster within 6 months: not having thought about underlying processes, I model this as a ~~Poisson process not unlike earthquakes, as if on any given day something unpredictable could spur FDA or whoever into action. From this, I'd downgrade my expected chances roughly linearly with time; is your model ~structurally dissimilar such that this does not apply?

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I don't think that's the Omicron booster model. It's more like one big decision, to begin or not begin, that takes a while to implement, and that we get evidence about over time and has already largely been made. Over time, we don't only learn that it didn't happen earlier, we use that to update on our distribution of possible probabilities of decisions that might get made later, and also it locks in people's decisions.

If instead all you can see is the boosters available or not outcome, that would be different, but also we flat out know we won't get one for a few months.

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Not disagreeing as such on China, but are you talking about official Chinese government statistics or your subjective assessment of the situation? Given the long history of authoritarian regimes cooking the books to cover up domestic crises, I would reserve some probability for China having at least one serious outbreak and the CCP trying to hush it up. To put some numbers on it:

Conditional on China having a major Omicron outbreak...

...the CCP tries to hush it up: 70%

...the CCP succeeds in hushing it up: 30%

...the CCP fails to hush it up AND maintains the "Chinese COVID Zero strategy was successful" line despite it being fairly common knowledge outside China that it's not true: 40-epsilon%

I'm tentatively willing to make book on those, if anyone can propose a resolution criteria I'm happy with. In the mean time, Zvi, it would probably be worthwhile to parse out "China keeps daily cases under 50 per million through 2022", "China fails to keep daily cases under 50 per million through 2022 and this becomes knowledge accessible to Westerners who are paying attention", and "China fails to keep daily cases under 50 per million through 2022 and the CCP admits to this" since those are all, unfortunately, different things. Of course, it's beyond the scope of this blog to track all of those separately, but it would be helpful to know specifically which you're talking about for future reference.

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RE: China keeping cases below 50/MM - part of this depends on if they follow through hosting the Olympics. If the world travels to China odds are very low - 20% maybe?

They have the will and means to implement pretty drastic measures, but in order to continue to contain spread they must be willing to impose all of those measures on politically powerful people all the time. My thinking is influenced by Dan Wang's 2021 letter:

- "Whereas Beijing is hit hard by every domestic outbreak, Shanghai hasn’t had many cases while being the least restrictive city in the country."

- "The currency of Beijing is power."

From what I can tell outbreaks have been controlled by

a) extreme border control

b) extreme limitations on traveling between regions

c) if you are well connected you can probably skirt many/most of those limitations (as evidenced by numerous outbreaks in Beijing)

d) the Olympics are going to give cause for the many powerful people to travel across the country to a super-spreader event

e) it won't take many invocations of "Do you know who I am?" to see a highly contagious virus far and wide

If it was just Omicron I'd give China 60% of keeping infections low, but Omicron & Olympics will be nearly impossible to defeat. The open question is do they care more about the international prestige of the Olympics or the international prestige of maintaining COVID Zero? I don't think it's possible to do both.

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