COVID-19 and the SARS-CoV-2 pandemic, how bad will it get?

This weblog started in the spring of 2002, in the wake of 9/11. Like much of the early blogosphere it was inspired and precipitated by armchair punditry that bubbled up out of the interwebs in the wake of that exogenous shock. Similarly, a whole set of financial blogs (e.g., Calculated Risk) popped up in the wake of the 2008 financial crisis. Crises seem to lead to changes in the information ecosystem.

In 2020 blogs are passe and most of the action of the “discourse” happens on Twitter and YouTube channels. But I’m still here, passing through multiple exogenous shocks, observing the world. To be frank, I think the coronavirus shock has the potential to be bigger than both 9/11 and the financial crisis combined. I have three children. One will remember quite clearly the pre-coronavirus world. One will be quite vague about it but have some fragments of memories before. And one will never know a world that wasn’t shocked by the coronavirus.

You wonder, could it be that big? In the middle of February, I began to consider how “big” the impact could be. Without major interventions, I assumed that the virus could infect ~30% of the American population, with a conservative case fatality rate of ~0.5%. In the United States of America, this yields about 500,000 fatalities. As it happens, this is less than the 600,000 who die of cancer every year. So what’s the big deal then?

First, these are to some extent excess deaths (presumably some of the individuals who will die of COVID-19, the disease, would have died of cancer or heart attacks the same year). Second, cancer is not contagious to doctors and nurses. In general, cancer is not contagious at all (some of the causes of cancer, like infection, can be contagious). Third, the treatment of cancer is generally a well-understood set of procedures (of various levels of effectiveness). Coronavirus, far less so. The stress on the medical system will be much greater and produce opportunity costs. This brings us to the biggest issue: the illnesses may come in a wave, and so overwhelm the medical system. Cancer occurs throughout the year.

I passed my numbers by a few people (e.g., Spencer Wells), and they thought they weren’t crazy, though they quibbled on particular parameter values here and there. By the middle of February I was becoming quite concerned, and, some of the people who along with me were quite sanguine around February 1st were now quite concerned as well. On February 28th I expressed my panic in a candid manner on Twitter. There were others who were like me. From a geneticist friend on March 2nd:

I have been trying to raise awareness in our local community through Nextdoor, and it has been very painful.

Especially because this is a very conservative area and somehow this has gotten politicized so that pro-Trump people think the coronavirus is just a cold

March 8th was the last time I was “out”, and I had a conversation with a neighbor who has a Ph.D. When my eyes started getting wild, and I told her she wasn’t going to see us for a while, she clearly thought I was crazy judging by her expression. On March 11th, she texted us that she was keeping her daughter home from school too.

But some people are still sanguine. To be frank, most of the skeptics of the impact of coronavirus are not very smart. I don’t say that judgementally, but a lot of the smart people who are skeptics seem to be keeping their mouths shut because of the taboo. The New York Times has a piece, Some Ask a Taboo Question: Is America Overreacting to Coronavirus? It’s ridiculous that such a piece even has to be written! Meanwhile, my friend Heather Mac Donald presented the skeptical take in her usual trenchant style over at New Criterion, Compared to what?

Some people reacted to Heather’s piece emotionally. Their reaction was basically “I can’t even!” I don’t think that’s what you should do. Lives and societies hang in the balance, and we need to remain rational. Entertain even views we consider offensive. This is a matter of life and death, not psychic trauma or metaphorical violence.

There are two skeptical takes from a more purely analytical perspective that I want to bring to your attention, A fiasco in the making? As the coronavirus pandemic takes hold, we are making decisions without reliable data, by John Ioannidis, and Coronavirus Perspective. I did not find Ioannidis’ piece persuasive because it relied too much on extrapolating from the Diamond Princess cruise. We now have Iran, Italy, and much of Western Europe. We also have the rest of Asia. I found the Epstein piece far more interesting because I made many of the same points in the last week of January and the first week of February to my wife.

Let me quote Epstein:

First, they underestimate the rate of adaptive responses, which should slow down the replication rate. Second, the models seem to assume that the vulnerability of infection for the older population—from 70 upward—gives some clue as to the rate of spread over the general population, when it does not. Third, the models rest on a tacit but questionable assumption that the strength of the virus will remain constant throughout this period, when in fact its potency should be expected to decline over time, in part because of temperature increases.

In relation to the first issue, I argued in early February that perhaps China, and Hubei, is different. We don’t know the comorbidities that are unique, and we don’t know if the Chinese healthcare system is particularly vulnerable. With foreknowledge, other nations will adapt and adjust. The spread of the pandemic to Iran and Italy, and now Spain and perhaps France and parts of the USA, indicates that the replication rate, R0, isn’t that different across societies without extreme measures. That is, the R0 ~ 2.5 or so.

In China, they drove it down to ~ 0.3 with an incredible vice grip of control. I see no evidence right now that we in the West will replicate that, though some nations are finally moving (France).

Second, from what I have seen many of the same broad patterns reported by the WHO in China have replicated in many other societies. And, the infection rate for children according to WHO is the same, with lots of passive spreaders. It is probably true, as Epstein argues, that the virus is targeting the most vulnerable first. But until we see real drop in case fatality rate I’m not sure that it’s swimming in the shallow end of the pool.

Last, the issue of evolution toward lower virulence, I’ve made this point. We shouldn’t assume that R0 and c.f.r. are fixed values. They may change. When I asked Greg Cochran his intuition on reduced virulence, he thought it would take years. That’s just too long for the present pandemic.

R0 and c.f.r. will change, probably for the better. But my wife watched the Wuhan epidemic closely, and we saw its rise, and how it fell, and what transpired in the interim. It was not pretty. There were cases of infected parents snatched from homes, leaving behind a small child who was fed through a hole in the door by neighbors. The child had no idea what was going on.

This sort of rapid and unconstrained isolation of infected individuals is unlikely to happen in the West. At least for now.

Reading the Epstein piece it’s hard for me to deny that I would have asserted its plausibility on February 1st. He says: “It is highly unlikely that there will ever be a repetition of the explosive situation in Wuhan, where air quality is poorer and smoking rates are higher.” Again, I said similar things. But the Italy case, in particular, illustrates that COVID-19 can impact very different societies. I think we need to update this prior.

That being said, I do leave open the possibility for mitigating factors in different societies and regions.

As of this writing, COVID-19 has had a mild impact on tropic Asia and Africa. This is peculiar because Chinese influence and contact across this region are ubiquitous. One of the reasons given for why Iran and Italy have been hit so hard is that they are economically intertwined with China. But much of Africa and Asia is similar. As of a few years ago, there were a million individuals of Han ethnicity living in Africa.

The primary explanation here is heat and humidity mitigating and retarding spread. Since I lasted talked about this more preprints have come out. Spread of SARS-CoV-2 Coronavirus likely to be constrained by climate and High Temperature and High Humidity Reduce the Transmission of COVID-19.

There are many hypotheses for why many viral infections are seasonal. UV light, people dispersing from indoors, absolute humidity, and temperature, are all candidates. No one knows for sure. When COVID-19 began to spread initially some researchers said there was no reason to think it would be seasonal. Though I think this is too strong (other coronaviruses are often seasonal), it was defensible. But the tardiness of the pandemic in urban Lagos, Bangkok, and Mumbai, as opposed to Seattle, Milan, and New York City, is suspicious. I think the most likely reality is that the “environment” (hot and humid) does have a mitigating impact on the spread. This means there is hope in the temperate latitudes as it gets warmer and more humid. I am not certain about this, but this is my own best guess.

One of the primary ways in which high absolute humidity prevents the spread of influenza is by increasing the size of expelled droplets, which fall to the ground. There is now a debate about whether SARS-CoV-2 spreads in aerosolized form or through surface contact. The WHO is still saying there is no airborne spread, while American researchers disagree. I think the Americans are right, as it explains the R0 better, and the different regional patterns.

Today I wrote about blood group differences in susceptibility. A reader pointed out that there is a mechanistic explanation in the case of SARS-CoV-1. I think that this phenomenon is probably real, in which case areas with very high fractions of O, such as Africa and Latin America, have a bit more slack. If individuals with blood group O are 30% less likely to get infected, that’s going to impact the R0 as a function of the proportion of the population that is O (in Chile it is 85% in Congo it is 60%). This does not mean you are “immune,” but, it does mean on a population-wide scale it makes a difference.

I have not talked extensively about ethnic differences in disease susceptibility. This is a thing. And sometimes it is harder to adduce than simple blood group differences (on average). But the empirical evidence of Iran and Italy suggest to me that genetic variation between groups in a coarse sense is not a major issue (one of the first British to die was of Bengali ethnic origin). When the COVID-19 GWAS is finished we’ll know a lot about individual and group susceptibility. But right now, we know that pretty much every group is at risk.

What’s the bottom-line here? Modeling is great, but we need more empirical data, though we do have some empirical data. The examples of Iran and Italy suggest that unfortunately, the Wuhan dynamics are pretty exportable and not sui generis, as we’d hoped. Hopefully, we’ll see some nations spared due to their unique conditions, which would lead us to believe that the whole world doesn’t need to engage in extreme containment strategies such as in Wuhan.

I’ve given less thought to social and economic consequences, but I’ll have a follow-up post where I tackle that issue.

Addendum: Not to forget, both age and density probably matter. Younger populations get infected, but are often asymptomatic. It is almost certain that lower density environments will exhibit less spread. Antique Old World cities are probably better for spreading this disease than American suburbs and exurbs.

8+

38 thoughts on “COVID-19 and the SARS-CoV-2 pandemic, how bad will it get?

  1. What have you read and what do you think of the studies using chloroquine or hydroxychloroquine for treatment. It looks like this has been reproduced a few times and in a few countries for moderate to severe cases it is part of protocol now.
    https://docs.google.com/document/d/e/2PACX-1vTi-g18ftNZUMRAj2SwRPodtscFio7bJ7GdNgbJAGbdfF67WuRJB3ZsidgpidB2eocFHAVjIL-7deJ7/pub
    https://www.connexionfrance.com/French-news/French-researcher-in-Marseille-posts-successful-Covid-19-coronavirus-drug-trial-results

    0
  2. Razib,

    you and Davidski are the bloggers I follow in Paleoanthropology since long, and I am happy about your performances in judging Covid-19. I hope you’ll get more outspoken now in economics and politics, too. The quality of rightist governments and the quality of neoliberal social policies lie open in this fundamental crisis — primarily in the U.S, the U.K. and Brazil. This is a truth moment.

    0
  3. Do you think the suppression strategy (plus closed borders) can actually eradicate it locally? Or is there inevitably going to be another flareup if we try to ease up on the restrictions?

    0
  4. @Razib: There is no guarantee that Covid-19 will become less severe over time. There are various epidemics which started mild and became more severe in the next season.
    I think chances it gets milder from one season to the next are good, but in the end it could take a dramatic turn to the worse by chance, simply because the appearing mutants are unpredictable.

    If the Covid-19 population stays big, widespread and intact, all kinds of mutations can appear and no serious scientist can predict with any certainty where we are heading to. Even a death rate like that of SARS is a future possibility. The only good news would be, in such a case, that the spread of such a strain of the disease might be slowed down by its aggressive symptomatic. However, considering the incubation period and how contagious it is, this might still be a very ugly thing.

    Many people seem to be much too optimistic still. Both considering the current containment and the progressive spread and development of Covid-19 in the future. We are in the dark and nobody can tell for sure how things might look like in 2 months or 3 years. This might be something we won’t get rid of or under control for quite some time in a worst case scenario.

    0
  5. I’ve personally run into many people online in the last few weeks (mostly of a “center-right” persuasion) who have begun to argue the “cure” is worse than the disease. That is to say, that the social distancing which has been instituted by the U.S. government (and elsewhere) is so severe it will cause Great Depression 2.0, and it’s better to just let the medical system get overwhelmed and have millions face preventable deaths.

    I find this argument to be morally repugnant. At the same time, they do have a bit of a point, considering the current mitigation strategies will likely need to be maintained for months to come – if not a full year or more in order to allow time for a commercially-available vaccine. One out of five U.S. workers is employed in either retail or entertainment/hospitality (and then more on top in education, airline travel, etc) – sectors which are now effectively almost entirely shut down. I see no way to survive this period without at least a temporary transition into some sort of command economy where the government will be the agent spurring economic demand, and even in this case there will be a great disjunction.

    Will western democracies have the wherewithal to actually maintain the current policies (closed schools, closed restaurants, lockdowns, etc) for more than say two months? If not it seems quite likely to me we’ll experience close to the maximum casualty rate regardless. Unless as you hope the virulence really does drop significantly in the summer months.

    2+
  6. It seems to me that if this disease had hit a pre-modern agricultural society it would be a nothing. Some modest percentage of the adults would die, but the kids would be fine, and a generation later everything would be back to normal. Various strains disease would still circulate, but everyone would get at least one of them as children, and would thus be partially immune to others as adults.

    Supposedly there are four types of coronaviruses that have been endemic for a long time, but only cause mild colds. Maybe this was the pattern they followed when they first entered the human population? The new type might follow the same pattern if we let it, but since modern society is so much more complicated and fragile than the old way of life we may not have that option.

    4+
  7. Holman W. Jenkins Jr “Questioning the Clampdown” in the WSJ today was saying we should justs let it go. The old people are going to die off soon enough anyway. We can get it over with quick: the whole thing is costing too much money.

    Nice of the WSJ to be so cavalier with the lives of their subscriber base.

    China tried to keep it quiet, Italy somewhat ignored it at first, and the British were saying they were going to try his strategy. All of them, when faced with the reality of having bodies in the streets when we run out of hospital beds, eventually changed their methods.

    I agree with obs on his point that the virus can get more deadly as well. The second wave of the Spanish Influenza being a prime example.

    0
  8. Interesting post Razib.

    One bit being covered in the news media here relates to generational attitudes towards the virus. Young people seem to be taking it more seriously than the elderly, in many cases, and it doesn’t (at least here) seem to have much to do with politics. Part of this may be that many of today’s elderly simply don’t “feel old” (“at 75, my Mom was old — I’m now 75 too, but I’m not old!”) and so underestimate the risk involved.

    In my case, we are having a hard time reliably convincing parents and in-laws that they really just need to stay home, except to buy food when needed.

    There are some natural experiments in all of this. I do wonder if the massive slowdown in industrial activity will lead to a noticeable increase in air quality, which in turn might be reflected in lowered severity of coronavirus symptoms (poor air quality exacerbates breathing problems). Anecdotally, the air smells a lot nicer around here in the mornings than it usually does.

    There is another natural experiment in the different reactions to the virus in Canada vs. the USA (two culturally similar but politically different places). Rates of infection and death due to COVID are running lower on a per-capita basis in Canada, and the difference may even be more stark once testing really ramps up on the American side. There is the usual criticism here of the government being slow to act, and mixed approaches among the provinces, but the Canadian political right is taking things seriously, and the provinces with right-leaning governments have been the first to shut things down.

    On the other hand, Canada is a cold climate, and depending on where you live, our winter easily lasts into early April — there’s a reason we call it “March Break” instead of “Spring Break”. So I do wonder if our virus season will persist longer than what one would expect in much of the USA (outside New England and the Midwest).

    3+
  9. The olders are more careless sometimes because some of them experienced really bad diseases and saw people dying when they were younger. Especially during and after WW2 a lot of people died not just because of the war, but because of hunger and diseases. To sum it up, they are harder, more experienced and used to people dying from diseases.

    When looking at millenials, child mortality, diseases, especially plagues, were almost no issue any more if ignoring clearly preventable STDs like HIV. If you think about Polio, Smallpox and Typhus, that are really nasty diseases which affected the young and children in particular. If you go through old records, seeing how many children died from pneumonia and many of the childhood diseases and now preventable causes, you get an impression.
    Obviously, in comparison to that, as bad as it is, Covid-19 is (so far) a mild diseases without a doubt. But our society and system is, in fact, no longer used to such epidemics and external shocks at all. And don’t get me wrong, its absolutely right to try to contain it, because the outcome is predictably bad enough and could get even much worse from one season to the next.

    To blame one particular party or political group is largely wrong, because I see it here in Europe, it depended on the developments on the ground. As long as it wasn’t a concrete threat to people, health system and society, practically no government reacted in an appropriate, anticipatory way – not a single one!

    Why? Because they were all afraid to act wrong, to overreact, to get the blame for the economic consequences especially if it turns out to be “not as bad anyway”. That’s the general problem of the current political climate: Nothing which needs effort being done if there is no overwhelming pressure to start it. The bigger costs for not acting must be clearly visible, actually tangible. Otherwise you can demand a political correction as long as you want, with the best factual arguments, doesn’t matter, you are just a troublemaker.
    If the current epipemic would get off lightly, those doing more to prevent a worse outcome would get all the blame for the economic and social costs. Apparently politicians are more afraid of that blame than of letting thousands die and risking a much bigger catastrophy if the disease gets out of control.

    5+
  10. We need random samples of the population, perhaps on the regular basis. This would help us with at least two important things: 1) understand the prevalence and mortality of the virus; 2) identify high risk groups that need to be target. It is amazing how people keep talking about “testing everybody” but (a) this is unlikely to happen, even in many rich nations and (b) census can often be worse than samples in identifying populations at higher risk.

    3+
  11. From Bloomberg, the average and median age of death in Italy from COVID 19 as of today 3/18/20 are 79.5 and 80.5 respectively. Certainly the loss of any human life is tragic, but locking down the country (and therefore the economy) to prolong the lives of the elderly is not a risk free action. The billionaire investor Bill Ackman just gave an emotional interview on CNBC concerning the virus and its impact, but there was a small part toward the end that mad my blood run cold, my own transcription “There’s a tsunami coming, and you feel it in the air, the tide starts to roll out, and on the beach people are playing and having fun like there is nothing going on. That is the feeling I’ve had for the last two months. And my colleagues at work thought I was a lunatic. OK, a lunatic, I’ve done stuff I’ve never done before. I’ve never had more than like, 200 bucks in my wallet, OK. I went to the bank and took out a large amount of money because of this concern.” This man is a billionaire, and owns major stakes in major American companies, and he is pulling hard cash out of banks. He did not elaborate further, but presumably he is doing so out of a fear that, some day, banks might not have cash to give. So while lifting the restrictions and simply letting the virus tear through the elderly population may seem, or in fact be, monstrous, what is the alternative? To put it no uncertain terms, if those numbers on your banking app stop meaning anything, and money stops coming out of the ATM’s, civilization will be put on hold. I don’t mean to be dramatic, I just want to be clear about what is now apparently possible. The economy cannot remain in suspended animation indefinitely, eventually it will die.

    2+
  12. @Mike: Even if you do not care for the elderly and vulnerable, if you let the Tsunami of this plague roll unchecked over the population and the weather doesn’t help out, the eventual panic and lockdown, the collapse of medical care and institutions would be even worse.
    What they need to achieve is at least to flatten the curve of the initial impact.
    This is not good will and humane care alone, probably it is not primarily about that at all. This is to prevent a societal meltdown.
    Just imagine in many absolute key sectors, which are now running, 30 percent would be just sick from Covid-19, with many relatives in hospitals fighting for their lives and nobody to care for their kids at home. I tell you it would be worse than keeping the current measures for a couple of months.

    Question is how effective the measures are to contain the virus and whether different weather conditions make a difference. If not some people might say it was in vain, especially if the curve doesnt flatten, but thats an unlikely worst case scenario imho.

    2+
  13. @Marcel: Absolutely. Damages to the lungs (pulmonary fibrosis) might be fairly common in the more severe cases, similar to SARS. As far as I read, that’s the case. Some lungs are practically dysfunctional and we might have patients which might need transplants on the long run, with organs looking like Swiss cheese.
    There is also damage to other organs, similar to a bad flu, the heart in particular, but in worst cases with lung failure some even end up “surviving” with permanent brain damages, dysfuntional organs, ruined bodies.
    So yes, looking at the severe cases, we should look at the long term consequences as well and if the virus doesn’t get contained, it will come back to us every season or even stay with us as an endemic threat.

    I’m also not that optimistic about a vaccine coming up in a short period of time and also not about immunity after having survived the infection. So there are a lot of open questions.

    2+
  14. Social distancing for months to an year is not a realistic option

    In any case all ( even extreme) social distancing can go is change the shape of the exponential growth curve so that medical services are not overwhelmed -this is non trivial

    As long as there are even a few cases out there and no herd immunity -the epidemic will restart -no?

    Consequently there may be just as much death/destruction from economic collapse

    Vaccine approval rules need to be loosened -other creative strategies will be needed

    The “guaranteed “ safety regime of the USA is untenable

    Calculated risks need to be taken

    Something bureaucracies are notoriously inept at

    The point is to decrease transmission till such time as we get herd immunity either by Russian roulette or vaccination.

    If a pharmacological agent has a. in vitro activity as a prophylactic and transmission decreaser b. Extensive record of safety even in mass administered public health campaigns
    C. Is inexpensive as hell
    D. Is easily available
    E. Production can be ramped up relatively easily

    What is the downside to putatively pushing this on to the public space ?

    Even if it decreases transmission by 10-20% ( or more). Smarter minds than mine, I am sure can model what effect that would have on an epidemic

    Chloroquine / Hydroxychloroquine meets all the above criteria

    The only potential downside is virus selecting resistant forms eventually -again smarter minds than mine -can that be modeled and / or mitigated

    https://www.nature.com/articles/s41421-020-0156-0

    0
  15. First time posting
    How do I upload a graph that is saved on my phones photo library to here ?

    It has some bearing on the warm
    Weather hypothesis for Covid -19

    0
  16. Sorry I don’t have time to look for an explanation online that answers the following question:. Is reinfection of the same idividual a matter of viral mutation, so that immune system is again naive to the virus core, similar to common colds/’flu’ yearly rounds with subtle crucial differences each time, if so what are the known/projected characteristics of this process in relation to C-19 versus other pathogens, is this a common uncertainty at first.

    0
  17. I think its best to compare Covid-19 with other Corona virus strains and for those people get a limited immunisation. So not like measles, but for months to years.
    But afaik the details for Covid-19 are still unknown. So for how long you are immune after recovery is an unknown factor. But rather unlikely its for life or even a decade.
    So even with just one strain, and this might change, people would need regular vaccination to keep it down if it stays with us, similar to the flu.
    Probably someone has newer infos?

    0
  18. My apologies to Razib -I know he doesn’t like repetitive posts ( been lurking since early 2000’s).

    From the French study above ( 1st comment)
    CQuntreated were all shedding virus at day 6
    But in the CQ treated group only 25% were still shedding at 6 days

    This strongly suggests a big effect on transmission

    The public health goal is to bring the R0 currently 2.2 ( highly transmissible)down to below 1 ( epidemic will peter out).

    Mass prophylaxis with CQ or HCQ is a potentially excellent way of achieving this

    Till most plasmodium developed CQ resistance and we had to switch to second third line antimalarial -CQ was the mainstay of malaria eradication efforts in india and the developing world ? 70’s 80’s

    I personally have taken at least 3 courses in my youth and have prescribed it at least 500 times. My best guess would be that between treatment and prophylaxis at least a billion people have taken CQ at one time or yhr other.
    It has a great and verifiable safety record

    Extrapolating from the in vitro study above it would appear that the malaria prophylaxis regime (500 mg CQ once a week) achieves desired viral inhibitory levels

    If yhr administration were to give a blanket med-mal amnesty to health care to prescribe CQ or even better make it available free of charge at state county and cityBOH it might become a win win strategy

    In india CQ is currently sold for < 1c per pill

    Production can be ramped up easily

    I personally and my family members have started taking it ( hcq 400/wk)

    I am pretty convinced that once a substancial number consume it R0 will come down

    Use, lobby, spread the word

    2+
  19. Something no one seems to be asking: assuming that high heat/humidity does slow transmission of novel coronavirus, wouldn’t the prevalence of air conditioning, especially in the US South/West, where it’s ubiquitous, interfere with this effect?

    0
  20. I’ve read that the RH even with AC in the summer still doesn’t get that low compared to heated spaces in the winter.

    That said if it was a problem, maybe the next move is after social distancing is campaign not to use AC in public spaces if that is true.

    0
  21. The southern US is getting hot. From Texas to Virginia temperatures will be in the 80s or higher. This should provide good information about the effect of heat.

    0
  22. It does seem that there is huge uncertainty margin in the case:death rate. There are clearly huge discrepancies between countries in case counts:death counts.

    Those don’t seem very well explained by “overwhelmed hospitals” as some of the jurisdictions with low fatality rates (low deaths:cases) have higher recorded case:country population ratios, e.g. Switzerland, Norway, Austria. These places tend to have higher numbers of tests per population.

    This is all from OWD’s Cov19 page – https://ourworldindata.org/coronavirus

    Even beyond South Korea, Iceland is a country in which they are doing virtually random sample testing – https://www.buzzfeed.com/albertonardelli/coronavirus-testing-iceland. So that could actually tell us something useful and meaningful about prevalance and case fatality ratio that isn’t the product of selected samples of people who are sick. (It’s also a literal ice-land with normal NW European demographics, so no “Warm climate and young population saves the day!” dodges!)

    0
  23. The Diamond Princess cruise ship data is intriguing. Nature’s experiment. In conditions, essentially designed for contagion and universal testing, over a period of month; only 17.5% got infected. Is that a proxy for the population of susceptible individuals ?

    1+
  24. Something possibly interesting developing in Florida. I have been tracking daily cases in NY, IL, FL Va and NJ more or less.

    NY,NJ, IL are exploding
    VA not so much
    FL barely budged

    Reporting aberration or beginning of a warm weather trend?

    0
  25. Saw the French paper
    1. Preprint
    2. Very small numbers

    Doesn’t invalidate it -but please dt o red e caution

    0
  26. Dear Razib, I would like to know your point of view re: the mitigating effect of heat and humidity as opposed to the fast spread of the pandemics in Brazil and Australia in the summer season of the Southern Hemisphere. Temperatures are well above 23C in those countries, with maximum temperatures often above 30C, and in the case of Brazil at least it’s the most humid and rainy season in most of the country. Nonetheless the number of cases skyrocketed to 970 from 98 in 1 week, and that is probably an under-reporting. How do you interpret that?

    0
  27. By the way, the rainy season is a flu season. So there seems to be ideal conditions (dry and cold, but not extremely cold) for the spread of the infection, favourable conditions (rainy, very wet) and unfavourable, reducing infectiousness (sunny/high UV, higher temperatures and humidity).

    Its not about the temperature alone, but UV rays and humidity (high but not too much, especially not rainy and cloudy) too. This is known from the flu and it will have an effect on Covid-19, as we can see and is the case. The question is just how much effect it has, how it alters R0 in a given setting.

    New infections won’t fall to zero, but drop.

    0
  28. Razib says
    Similarly, a whole set of financial blogs (e.g., Calculated Risk) popped up in the wake of the 2008 financial crisis.

    Calculated Risk was there since 2006 at least.
    They quoted others and predicted a collapse Financial collapse as early as 2006.

    I was working quant/risk analyst in the Fixed Income, Bonds, Mortgage Backed Securities (MBS), Credit Default Swaps (CDS). So a lot was being discussed made sense.

    I learnt much from reading that blog specially what Tanta (Doris Dungey, RIP) wrote. It all made sense and I started betting against the market with PUT options, I guess late 2006. I made over 10x what I invested/lost. (normally I dont gamble/invest in stocks, this was a sure bet).

    Some posts I did about Tanta (Doris Dungey, RIP)

    What Tanta said then in 2007 is still true as we are finding out right now
    That does imply—as JPMorgan also implies—that the Big Dogs have more cooties on the balance sheet than they’re prepared to tolerate. Looks like total war to me.

    http://sbarrkum.blogspot.com/2011/01/excerpts-from-tantas-posts.html

    0

Comments are closed.