And if you're in Switzerland, maybe avoid members of parliament? They just celebrated a 70-year old politician's birthday in the parliament building with crowds singing and playing wind instruments maskless. And then tweeted proudly about it.
If you're in the US, it's probably worth isolating yourself even more post-Thanksgiving break - whether you travelled or not. It's quite likely that cases will spike in the next 7-10 days because of everyone else's travels. Even if there are few cases in your town now, meeting people means that you will be exposing yourself to the risk levels of other parts of the country that may be in much worse shape.
And if you're in Switzerland, maybe avoid members of parliament? They just celebrated a 70-year old politician's birthday in the parliament building with crowds singing and playing wind instruments maskless. And then tweeted proudly about it.
In response to a question about whether covid was circulating in the US in December 2019:
I think it's quite unlikely to be true. This is the best thread about it that I read: https://twitter.com/trvrb/status/1333647437869633537
1) It's probably cross-reactivity from seasonal coronaviruses (as the authors discuss themselves). If I understand correctly, there was only 1 sample in the entire study that tested positive to the most COVID-specific assay (S1-specific Ig). 39 samples tested positive for less specific tests.
2) The raw numbers are not very persuasive (3/519 tested positive in their 'true negative' set of older samples, vs 39/1912 in the set they were evaluating). It's a convenience sample and the authors themselves argue that inferential statistics are inappropriate. But if you ignore the convenience sample and do a Fisher's Exact Test, you get p = 0.02 (not my analysis, see linked Twitter thread). Not very convincing.
3) 39/1912 is about 2%. If you ignore the convenience sample and assume that it is true and representative, where were all the dead people? The hospitals would have been flooded. Also, at least one big testing campaign done in Jan turned up nothing.
Basically, it's an awfully weak result to hang such a major conclusion on. And it's in conflict with a fair amount of other evidence. So I'm quite sceptical and inclined to ignore it, at least until more evidence is provided. It's not impossible but this evidence is too weak to shift my priors meaningfully.
While sharing the story of a friend who was infected with covid twice:
There could well be long-term effects of the illness, even for the young.
In most parts of the world, the situation now is worse than it's ever been since this started. We have 3 vaccine candidates that should be here in months. Hold on! Don't give up on being careful now - we could be past this in a few months. If you must meet family or friends for holidays (better if you don't), use masks and ventilation (a few open windows makes a big difference) where possible. If you are unsure about what measures are effective or anything else, please ask and I'll hunt down whatever information you need.
Coronavirus news #8. As always, please point out my errors. Not an expert in this specific domain, but I have relevant training and am trying to keep up to date. Which is becoming harder and harder, so read this - and everything else on the topic - with a sceptical eye. I encourage those of you with relevant expertise to also spread your understanding as best you can.
1) Despite improvements in treatment, the number of reported daily deaths continues to climb globally, albeit slowly; it's now about 5500 per day, which is an underestimate. Brazil, India, Mexico and the US account for a big chunk of those, with Colombia apparently set to join that group. In all of them the number of daily reported cases is stable or increasing. And the fraction of tests that are positive in those countries is increasing over time, which means that we are missing more and more cases. The fraction positive is perhaps stable in the US, but there are additional wrinkles there. The US is seeing increasing time lags between the test being administered and the result being declared, especially in the states with the biggest outbreaks, so the true fraction positive is quite possibly still increasing. South Africa is also probably in very bad shape; there are reports that the true number of deaths is more than twice as high as the reported numbers, and the fraction of positive tests is skyrocketing. And South Africa is the worst on the continent, but there have been large increases in cases in many African countries recently, after a long period when they had done very well.
2) We've now got better evidence that some people have pre-existing immunity, or at least produce antibodies that probably confer some immunity. This had been suspected for South-East Asia; now, a study of blood samples in the UK collected before the pandemic found antibodies that neutralise the virus. In the 6-16 year age range, 60% produced these antibodies; it was very low in older people. These neutralising antibodies were probably formed in response to other coronaviruses that cause the common cold, and their similarity to SARS-COV-2 likely provides some protection (though we do not know this for sure). This is one small study in the UK, but it seems to have been reliably done. If confirmed, it could be very important, especially if some poorer countries have had higher exposure to these coronaviruses & greater prevalence of immunity. More details at: https://twitter.com/KevinWNg/status/1286600426264158213
3) We also have some good vaccine progress! 3 vaccines looked promising in phase 2 trials, which check for safety. They showed the signs that we associate with them being effective (stimulated antibody production), though these trials could not test if they actually protect against COVID. They have now started phase 3 trials to test this specifically. A fourth vaccine has been approved by China on an emergency basis without phase 3 trials, and many more are still in phase 2. At least one of the phase 3 vaccine teams has built up massive manufacturing capacity, so if it works, we could start to see vaccines being widely distributed in months. Distribution is a challenge that needs to be discussed globally, because it is likely to come down to a power struggle, especially given the US govt's recent behaviour on this front.
UPDATE: 2 more vaccines entered phase 3 trials on July 27.
4) We also have more and more evidence of bad non-lethal effects of COVID. A few studies now have found fairly long-lasting effects well after the virus has been cleared from the system. The latest in a study that seems to have been done well, is that nearly 80% had worrisome heart symptoms at least 2 weeks after being deemed fully recovered. Most of these patients were never even hospitalised; they had mild cases. An earlier study in Italy more biased towards severe cases found that ~90% had serious symptoms after recovery from COVID, including fatigue, chest pains, joint pains, and more. More than half had 3 or more of these symptoms. Some less-rigorous work suggests long-term lung damage may be common too. So even as our ability to save lives improves, it's really important to remember - and remind people - that this is a horrible disease even if you survive.
5) Binary thinking has been a massive obstacle to good decision-making. Politicians, administrators, health organisations and members of the public have all defaulted over and over again to a yes/no framing: masks/distancing/lockdowns/medicines either work or do not work. This thinking is simply wrong, with rare exceptions such as the idiotic notion that 5G causes COVID. Almost every measure is somewhere between 0% and 100% effective, and we need to consider the costs and benefits when deciding whether to use them. This seems like such a trivial point that I've not bothered to make it before, but it keeps coming up in people's objections, so I guess we need to argue this explicitly. Standard masks appear to protect wearers by filtering out 60-70% of viruses (they do an even better job of filtering out the viruses you exhale/sneeze/emit, of course). That's well short of perfect but a huge improvement on 0%; they are also cheap and so we should obviously use them. Especially because (i) getting a smaller 'dose' of viruses likely means you get a milder infection, and (ii) combining multiple somewhat-helpful measures can get the effective reproduction number below 1, which would kill the pandemic.
6) The last point is relevant to vaccines because in a few months, we are going to be in a very complicated situation. The first vaccines we get are very likely to give us imperfect protection; they may reduce the probability of infection by something like 50-60%. They may come with some side-effects - hopefully mild ones, but we don't know. Even in the small phase 2 trials, a fairly high proportion of people had mild side-effects. With more people, we might find rarer but more dangerous ones. Some people will quite possibly die of those side effects, because even a very rare, relatively weak side-effect across billions of people is likely to cause a few deaths. And because we will try to distribute these as fast as possible, there will be accidents caused by failures of process and quality control. Taking these vaccines will still save a huge number of lives, assuming we do not discover bad side-effects too late in this process. This is going to be a hard message to communicate, especially because multiple vaccines will arrive in succession, with different characteristics and side-effects. Different vaccines will also end up being distributed in different places. Which specific vaccine you get may depend on complicated geopolitics, supply chains, pre-existing government investment, corruption/kickbacks, and more. It is going to be very easy to spin a conspiracy around this. There is going to be a flood of anti-vaccine rhetoric, aided by people's fears of multinational corporations and foreign countries, opportunistic politicians, lousy science journalism that focuses on individuals cases of side-effects (both real and imagined) while ignoring the big picture, and terrible science communication by governments and health organisations that deny the side-effects to tell an oversimplified story. So please start to talk to people you know about what to expect! We need to discuss this now and not wait till the story is told by the usual clowns.
7) Of the trillions that are being shovelled into the world's economies to try to keep us afloat, only a tiny fraction is being deployed towards actually stopping or curing COVID. Less than 10% of US spending relating to the virus is directed towards stopping it. Even from a purely financial perspective this is insane - if we could stop this pandemic just a few weeks earlier, we would save trillions! A government that cared only about money and nothing about people's well-being still ought to be spending orders of magnitude more (or at least many times more) to provide tests, protective equipment, medication and vaccines. There's also a very strong argument to be made for offering free masks, free testing, incentives to get tested regularly and quarantined, and more. Somehow, 7 months into this process, in a large part of the world including the US, India & most badly-affected places, we are still short of protective equipment and tests, and contact tracing is rudimentary at best (even Switzerland seems to do a mediocre job of it, though I don't know enough to be confident). Even the massive increase in testing capacity in the US is something of a sham. In many places, test results are being reported 1-2 weeks later. Nobody is quarantining in that period, which means that the testing is effectively useless at preventing spread.
8) This fear of damaging the economy continues to drive countries & regions towards reopening too early or taking action too late. This is a massive failure on multiple counts because: (i) the economy will not recover while the threat of more outbreaks looms over us, despite the cavalier idiots who go to nightclubs in the middle of a pandemic, and more importantly (ii) it takes much longer for new cases to halve than for them to double. We now finally have fairly good data on this. Delaying measures by 1 week prolongs the need for lockdown or other strong measures by about 3 weeks. And in Switzerland, which has seen about 2000 deaths, starting the lockdown 1 week earlier could have saved about 1600 lives; starting it 1 week later could have cost another 6000 lives (based on a study that seems reasonable to me: https://www.medrxiv.org/con.../10.1101/2020.07.21.20158014v1). 7 months in, and the basic lesson to act quickly is being ignored. Our health and governance institutions have failed us in many countries.
9) For months, we have had multiple methods to do rapid testing at home. There are even paper-based tests which would cost 1 or 2 dollars, and give results in an hour or so. They are a bit less sensitive, but could be deployed at massive scale to monitor whole populations. Why are we not using this? In part because this requires approval and deployment by healthcare agencies. And these have been and continue to be atrocious. The WHO & CDC have spread wrong and disastrously damaging messages. The WHO screwed up the distinction between 'presymptomatic' and 'asymptomatic' with dire consequences for people's perception of risk. It is just now acknowledging the possibility that the virus might be airborne, something we have known for months. The CDC is now advocating that universities reopening in Fall do NOT do mass testing of students because the possibility has not been properly studied. This message is not just completely wrong, it is devoid of any logic - the burden of proof is on the party saying mass testing does not work because of all the evidence we have in favour of it. The CDC also keeps changing its recommendations for what universities, churches and other institutions should do based on US govt. political priorities. The FDA has possibly been the worst of them all, holding up important, scientifically-valid steps consistently, such as the cheap tests I mentioned. It only just approved pooled testing, a simple and important method I wrote about in March and that we have used since the second world war. We may need these organisations to exist in some form, and their work has been hampered by political meddling, such as the US govt's decision to exclude the CDC from the data aggregation process. But everyone should seriously downgrade their belief in them for now. And I say this as someone temperamentally and politically inclined to favour these institutions.
10) At least part of the big drop in the probability of dying once you are infected is because we have made many small improvements in medical care. One that I missed is that doctors now turn very sick people onto their bellies for extended periods of time, which apparently improves how much oxygen they get. This seems to help a lot though I'm not sure of any study about this that specifically shows that it reduces COVID mortality. It's remarkable to me that this simple step may save a lot of lives.
11) Some of the most common antibody tests are apparently testing for the wrong antibodies; the ones being tested for do not provide protection. They are probably correlated with the right ones, but it's not great news: https://www.nytimes.com/.../coronvirus-antibody-tests.html .
12) That ghastly IHME model that I griped about in March and April continues to influence policymakers in many countries. Despite months of criticism and many much better models, this continues to grab headlines despite being a trainwreck. The IHME predictions for the near future do worse than the *baseline prediction*! That is, using just the average deaths from the previous week gives you a more accurate prediction than this stupid model. Please just ignore it and downgrade your belief in any claim based on their predictions.
13) There's yet another push for hydroxychloroquine by the usual gang of idiots in the US. Far too much money and scientific effort has gone into that already; the most wildly optimistic scenario appears to be that it does very little. This electioneering propaganda does not just affect the US, which would be bad enough. The garbage they pump out is picked up and spread in the developing world too (including by people I know), where people are less clued in to the ins and outs of the insane US political landscape and how it distorts pretty much everything. The consequences are global.
14) I continue to be very uncertain about the progression of the pandemic in India. The number of new cases per day has followed a slow but steady exponential for several months, with very little deviation from that trend for several months. Tough (but terribly planned) lockdowns, reopenings, changes in policy, wide variation in medical systems and political leadership across states, and yet the overall pattern has been incredibly stable. The fraction of positive tests has been going up, so the true picture might be a slightly faster exponential than the simple one. But overall, it seems strange and I can't explain it. Some amount of immunity within the population and the lockdowns would help explain why the increase has been slower than elsewhere, and much slower than I anticipated. But I cannot understand why there's been so little change in the trend through time. I really hope we can trust the data. I don't expect it to be great, but I presently have no specific reason to suspect fraud. We desperately need some random sampling of the population to understand what's going on, but that is a massive challenge in a population as complex as India's.
UPDATE: Well, I guess there is evidence of bad/fraudulent data reporting from India. This is still at a local scale but could be important if it's widespread, which is probable: https://www.bmj.com/content/370/bmj.m2859 & https://scroll.in/.../to-battle-covid-19-india-needs-to....
UPDATE 2: And now national-scale information: https://www.medrxiv.org/con.../10.1101/2020.07.19.20157248v1
In response to a question about evidence that surfaces are not spreading the virus:
Good question, I wondered whether I should write more about it then. I think one's prior beliefs/priorities matter a lot here, so let me be explicit about mine first. I think there's a limit to how many precautions people will follow, especially over the length of time we need to stop this pandemic. The more things we ask people to do, or the more complex they are, the less likely they are to be followed. And if people stop following some guidelines and nothing bad happens, they will be more likely to stop following other, more important ones too. So it's important to focus efforts on getting people to follow a few important and simple guidelines for the sake of general compliance. At the individual level, it can be perfectly rational to go beyond these guidelines. With that as preamble:
Essentially nobody challenges the idea that transmission by fomites (particles on surfaces) is possible. The question is whether it happens in the real world, and at a frequency that's high enough for us to mandate/suggest specific actions. The WHO considers fomites to be a plausible mode of transmission, but their report also states: "Despite consistent evidence as to SARS-CoV-2 contamination of surfaces and the survival of the virus on certain surfaces, there are no specific reports which have directly demonstrated fomite transmission". Their communication of scientific evidence has been poor, so I looked into what epidemiologists & virologists were saying, especially on Twitter. After months of contact tracing around the world (albeit much less than ideal), I've encountered discussion of only 3 cases where transmission by fomites (particles on surfaces) may be more plausible than other explanations, and that's being generous (see first Twitter thread below). Even these cases are very far from certain. And infection rates within households seem to be lower than one would expect if surfaces were important for transmission.
Since it's hard to show a negative, there's no paper I can point you to which spells this out clearly, or states precisely what the relative risks of surfaces vs. droplets/aerosols are - the numbers are still unknown! But the specialists have generally downgraded their perceptions of the risk of surface transmission, though they hedge their public statements appropriately. See the articles & tweets linked below.
Three caveats: (a) it's a hard topic to study, so it's possible that fomite transmission has happened where contact tracing has been unsuccessful, (b) fomite transmission may have been incorrectly attributed to aerosols in spaces like offices, and (c) since hand-washing and sanitising was one of the major initial recommendations, we may have stopped transmission via fomites in the real world. If we ease up on that, it may start to happen.
Despite those caveats, I think that the balance of evidence so far suggests that surfaces are not important. I understand the desire to take precautions, but personally don't sterilise things I bring home, and did not do this even when the risks were higher here. I have recommended to concerned family that they could consider just leaving things on a balcony for a while if they wanted to be very safe. Virus numbers on plastic decrease by a couple of orders of magnitude in two days in cool, dry conditions; it's much faster when warmer and more humid, and on most other surfaces.
[I've linked to a few papers below, but they seem less helpful than they appeared. I found the threads on Twitter more helpful because they were to the point and open to immediate challenge from other experts.]
https://www.nejm.org/doi/full/10.1056/nejmc2004973 (can survive on surfaces)
https://msphere.asm.org/content/msph/5/4/e00441-20.full.pdf (...but decays faster at higher temp & humidity)
https://academic.oup.com/.../doi/10.1093/cid/ciaa905/5868534 (hospital surfaces have viral RNA but no viable viruses found)
https://www.thelancet.com/action/showPdf?pii=S1473-3099(20)30561-2 (much-publicized commentary, not the most useful, I think)
https://wwwnc.cdc.gov/eid/article/26/9/20-1798_article (suspected fomite transmission, weak evidence and could well be aerosols)
https://wwwnc.cdc.gov/eid/article/26/6/20-0412_article (suspected fomite transmission, weak evidence and could well be aerosols)
https://www.cdc.gov/mmwr/volumes/69/wr/mm6914e1.htm... (suspected fomite transmission, weak evidence)
https://www.who.int/.../modes-of-transmission-of-virus... (WHO report mentioned above)
https://www.krisp.org.za/.../StAugustinesHospitalOutbreak... (hospital outbreak in which physical contact or fomites are suggested but without much evidence, see page 20) ". Summary at https://www.sciencemag.org/.../study-tells-remarkable...
https://www.cbc.ca/.../coronavirus-surfaces-groceries... (general article, several experts offer their opinions)
https://twitter.com/DiseaseEcology/status/1279097818351726592 (good thread summarising the best known case while highlighting its rarity)
https://twitter.com/firefoxx66/status/1260905943933620226 (see rest of the thread too)
https://twitter.com/LucyStats/status/1282112670230106112 (contrary opinion)
UPDATE a week later: A recent Atlantic article on the topic summarises this pretty well: https://www.theatlantic.com/ideas/archive/2020/07/scourge-hygiene-theater/614599/
It does lean a bit on that commentary piece that I thought was not very helpful (among other things, it misrepresents the goals of the papers on rate of viral decay on surfaces). But that's a minor weakness.
I mentioned in my last post that an increase in US virus deaths was expected this week after 2 months of steady decline.
Well, it's here (see bottom right graph).
Earlier, cases were increasing but deaths decreasing. This mismatch had multiple possible explanations, and this week's reversal supports the main one I wrote about - that we had been catching cases earlier than before. There were more hopeful explanations, such as that we had shielded vulnerable populations successfully.
The worse news is that this will probably grow for weeks. First, because we've got about 4 weeks of case increases baked in. Second, because many of the recent cases were from young people. Given the competence with which this has been handled, they have probably passed them on to older people, who will fall sick later and start to die later, but at much higher rates.
What a shitshow.
In response to a question about whether the daily death curve would eventually match the daily cases curve, implying about 4k deaths per day (after accounting for undertesting in April):
Mercifully the better projections don't foresee anything quite that extreme; it looks more like 4-6k per week rather than per day. I don't fully understand why that is, but I think it's largely because the age distribution of recent cases has skewed younger and younger. That has reversed recently (see this plot for Florida, for e.g. https://twitter.com/.../status/1283134585665200131/photo/1) and that will probably show up as an increase in another 3-4 weeks. Big uncertainties, as you know, especially because this involves forecasting policy and behaviour to some extent.
Those forecasts I mentioned: https://covid19-projections.com/us & https://viz.covid19forecasthub.org/. (The first shows deaths per day, the latter per week).
Coronavirus news #7. As always, please point out my errors. I started making notes a couple of weeks ago before getting side-tracked. In the meantime, we've had 2 million new reported cases - about 20% of the total.
1) About 4000-5000 people are reported to die everyday because of this virus, or about 3% of all deaths. Globally, that has been stable for nearly 2 months. The true number is almost certainly higher, but it's unlikely to be by a whole lot (high uncertainty in India and some other places, though). Please remember that the people who don't die don't all recover completely. Many, many more are being struck with long-term damage to their health. That includes a substantial number that don't have any symptoms and may not even realise it now; many asymptomatic people show signs of lung damage in scans. So though it's normal to have one's standards for safety slip after all this time and with fewer immediate consequences in our daily lives, please be safe. Wear a mask.
2) Though the US mostly leads the news, Brazil and possibly Mexico are likely in worse shape, with India bidding to take this miserable crown. South Africa also seems fairly likely to join that group. Nobody really knows what's happening in Russia, because there's clear signs that some of the data being released are junk. Unlike the other countries, the US has actually been declining in deaths per day since the beginning of May. Brazil, Mexico, South Africa and India are still increasing, and the first two have substantially more daily deaths than the US. There has been a worrying drop-off in reporting (even by scientists) about the state of the virus in the developing world, with Brazil being a partial exception.
3) The US has seen explosive growth in cases in the last three weeks but deaths per day have actually declined since early May. There's multiple reasons for this. A greater proportion of new cases are in younger people (~10-100X less likely to die), we have developed better methods to manage severe illnesses, and perhaps most importantly, we are catching cases earlier. The last point implies that the lag between increases in cases and increases in deaths should be increasing. It used to be about 2 weeks; it may be 3 or 4 now. If this hypothesis is true, we should see increases in deaths across much of the US in another week or so. We can be fairly confident that the growth in cases is not simply because of more testing, because many of the outbreaks are also seeing an increase in the percentage of positive tests - a sign that an increasing number of cases is being missed.
4) Europe shouldn't feel too thrilled. After getting things under control, they've messed up the reopening and experienced about a month of increasing daily cases. Switzerland has finally mandated mask usage in public transportation. I think that ought to be the minimum policy change that we should aim for. There seems to be reasonable evidence that mandatory mask usage and closing some activities that involve crowds or closed spaces (e.g. bars) would be sufficient to kill the pandemic. Mask usage alone does a lot of the heavy lifting. Even tighter restrictions would do it faster but might be overkill if the situation is not yet out of control.
5) Antibodies are the focus of 2 important types of testing: (i) testing to figure out if someone has had the disease and will therefore be immune, and (ii) testing to figure out what proportion of the population has been infected by the disease ('seroprevalence studies'). This is how we get exposed/infected numbers like 5% of the Spanish population (it's similar in the US). But we now know that antibodies actually decay below our ability to detect them relatively fast, roughly on the scale of months. This does not mean that these people have lost immunity; they almost certainly retain the ability to produce more antibodies in the future if re-infected by the virus. Also, some indeterminate (but probably low) number of people apparently tend to not show much of an antibody response. However, most (if not all) people develop another type of immunity that is mediated by specialised T-cells. These provide long-term immunity and are generally ignored because they are much harder to test for. They are not quite as effective as antibodies but are likely important, though we don't know much about their role in COVID immunity yet. Bottom line: (a) we are still fairly confident that people develop immunity after infection, (b) the antibodies we test for decrease over time but we retain immunity, (c) this antibody decrease & T-cell response adds an unknown but probably small bias to our estimates of how much of the population has been exposed.
6) There appears to be some pre-existing immunity in people who were infected by SARS-1 many years ago and by an unknown coronavirus. There are 7 documented coronaviruses circulating in human populations, but there is likely an unknown one circulating in South-East Asia that has protected populations there through this 'cross-immunity'.
7) Most evidence points towards us being very far from any sort of herd immunity. If the governments of the US, India & Brazil give up on containing this, I would say we are heading towards millions of deaths with high probability (given their failure so far, we are headed there already with moderate probability). To speculate even further, tens of millions is not implausible in this scenario.
8) Last month, I wrote that perhaps 80% of new cases are caused by 10% of infected people (superspreaders). This has important implications for how to do contact tracing. The standard method is to find everyone an infected person was in contact with and notify/quarantine them. But since they were almost certainly infected by a superspreader, an improvement on this is to identify the superspreader who passed it to them and then trace everyone they were in contact with. This 'backward contact tracing' can be thought of as a second level that makes the whole procedure much more effective at stopping an outbreak. That said, contact tracing isn't feasible when you have a massive ongoing outbreak.
9) There is now plausible but inconclusive evidence that the virus has adapted during its spread. A mutation that increases the spread in limited lab experiments has also come to dominate in new cases around the world in the last 3-4 months. But it could have spread more just by chance, by being in the first cases that spread to new places. However, the mutation does not appear to do anything to the virus' lethality, so this evolution has not made things any better for us. And it does not change anything about how we should prepare for or treat it.
10) Despite all the press about treatments, no specific medication we have so far is close to being a cure. Hydroxychloroquine does not do much and has wasted time and money. Remdesivir and Dexamethasone have relatively weak effects or limited use-cases; they will save lives but are not cures. When used most effectively, dexamethosone appears to save about 25% of lives lost. This is progress, but we need a lot better. Both also have severe, dangerous side-effects that can kill. We are on the way to having monoclonal antibody treatments, probably within a few months. This would be a big improvement but is probably going to be expensive. The US appears to be doing its best to corner the market on these right now, though that investment should stimulate more development.
11) Children appear to be about 1/3 to 1/2 as likely to get infected. And they are much less likely to fall seriously ill or die once infected; they have ~100X lower probability of dying if infected, relative to people over 80. This has obvious implications for reopening schools and colleges. I think doing so is probably feasible if coupled with distancing, mandatory masking, and mass testing on a regular basis to catch outbreaks early. But the details matter a lot.
12) There's now even more evidence that surfaces are not that important for spreading the virus.
In response to a question about whether we were headed in the right direction at this time:
Absolutely in the wrong direction in the US right now.
We still don't have enough tests or protective equipment, mask usage is not high enough, people in outbreak areas appear to still be frequenting indoor restaurants (less than normal, but still), new cases are going up rapidly, and the federal government & the CDC continue to be disastrous (more on that soon).
The main good news is that deaths per day are much lower than May, but as I said above, I expect that to increase soon. There's a phenomenal amount of scientific talent, of course, but it's not much good if the people in charge are incompetent, malicious or craven (or some combination of the above).
Other that that, the prospect of monoclonal antibodies, some advances on treatment, and some progress on the vaccine front are all encouraging. But none of them is close to deployment.
Coronavirus news #6. As always, please point out my errors. Not an expert in this specific domain, but I have relevant training and am trying to keep up to date. I encourage those of you with relevant expertise to also spread your understanding as best you can.
1) It's happened without much fanfare, but it seems as though contact with surfaces is no longer thought to be a very important method of spreading the virus. In March, there was a lot of advocacy around using gloves, washing hands, & avoiding face touching. As more evidence has poured in, the cautions and analyses have shifted towards focussing strongly on inhalation of viruses. I have yet to see clear research on the relative risks (please tell me if you know!), but I think this is a fair summary of epidemiologists' present beliefs. I'm not saying that viruses do not spread through contact with surfaces, so continue to take reasonable precautions. But I offer this to allay the fears of friends who go to incredible lengths to sanitise everything they buy or that enters their house. Letting new acquisitions sit in the sun for a week is overkill.
2) Brazil and India have exponentially increasing case numbers despite lockdowns - in India's case, one of the most brutal in the world. The outbreaks are concentrated in some regions, so it is possible that they will get contained. But given exhaustion with the cruelly mismanaged lockdowns (at least in India), I'm doubtful they will be. And they have
20% of the world's population between them.
3) As a consequence, the situation right now is far worse than I think most people realise. Global daily deaths are slowly decreasing (currently ~3000 per day), driven by improvements in the situation in Europe and the US, which were hit worst. The news is moving on to the economy, tourism, protests, and so on as local situations seem to stabilise, and people get bored or desperate. But this apparent progress can be quickly reversed by just one or two new outbreaks that can happen anywhere, and these seed new outbreaks in turn. We do not have a single pandemic, but a patchwork. Regions/countries with outbreaks can be isolated, but the success rate needed to prevent them seeding new outbreaks is very high. Most countries have not displayed the competence needed. We are stuck in this situation till we have a vaccine.
4) As India's & Brazil's numbers rise, global daily deaths will start to increase again. We are now looking at possibly millions to even tens of millions of deaths. This probably seems unlikely to you and I hope it's totally wrong. But in March, the possibility of tens of thousands of deaths was seen by many as unwarranted pessimism, and hundreds of thousands as wild fantasy. And yet here we are. We ought to learn something from this about how unreliable gut impressions about worst-case scenarios and tail risks are. And perhaps eventually turn that insight towards another area where scientists have spent decades venting their spleens about tail risks: climate change.
5) A better argument for why millions of deaths is plausible: a few weeks ago, Spain and France did the biggest & best random testing programs run so far, helping to fill a massive gap in basic data. These found that the infection fatality rate is about 1%, just as epidemiologists have been saying since at least March. Remember that infection fatality rate is the % of people who ever got infected that die, which is the number we are most interested in. Most reports have been about the case fatality rate, which leaves out all the people who got infected but did not know about or report it; this varies a lot based on medical system and reporting practices. Also, about 5% of those countries had been infected (i.e. had antibodies) at the time. If the virus were to continue to spread, you would not get 20 times as many deaths, but you would get very large numbers that are in line with those that basic epidemiological models predicted months ago. Apply that logic and the basic numbers to other parts of the world and you gets millions to tens of millions.
6) A particularly worrisome pattern: there are many more young people infected and hospitalised in India and some other countries than was expected. There's multiple reasons why this may be, such as exposure patterns and data biases. There are more scary possibilities but right now no real evidence for them. But even so, outbreaks among young people are a massive threat to countries with much younger populations, where the hope was that the vulnerable elderly could be isolated while the young slowly return to work.
7) Since I'm thoroughly sick of the endless debate around Sweden and its tactics, allow me to point out stories from other countries that are not discussed much. Take Mongolia and Vietnam, which have had zero deaths between them with a combined population of 100 million. Zero. And they share a border with China! Senegal, though further away, has had about 40 deaths in a population of 31 million. Ghana: about 35 deaths among 16 million people. Ethiopia: 12 deaths out of 115 million. All these countries are relatively poor and lack the capacity of European and American healthcare systems, in terms of manpower, training, and technological sophistication. What they share is that they took action in January, while more developed countries did nothing. I'll add that they are also younger, but I think that is a less important factor. Ghana and Ethiopia are noteworthy, because I understand they implemented better contact tracing than most of Europe or the US. Ghana also tested large numbers of people by using pooled testing, an old method I discussed in the very first of these posts in March. Germany and India have also been using the same strategy, which should have been employed months ago. I was personally terrified about outbreaks in developing countries, and want to highlight that many of them have outperformed the wealthiest countries to an impressive degree, one that ought to shock us. They may yet suffer badly, but they have done well so far.
8) Reopening in many countries is politically inevitable now and justified in many cases. Did the lockdowns work? It's a question that's going to be contested very strongly because of the political and economic implications. But please keep in mind that this is not exactly a yes/no question. There was not a single type of 'lockdown'. Instead, there was a wide range of activity restrictions, ranging from stay-at-home with almost no exceptions (China, India, Italy, France) to limitations on gathering places such as restaurants & movie theatres but not much else (Switzerland) to essentially no legal limitations, just recommendations (Sweden, Ethiopia). There were successes in countries in all these categories. So a case could be made that the strictest stay-at-home orders were not needed, at least in areas without high population densities. But let's put that in context. Strict restrictions were entirely justifiable at the time given the limited information we had and the very real threat of having healthcare systems overwhelmed (as happened in northern Italy). Shutdowns were protection against very real tail risks. Additionally, even the places with no limitations did have big reductions in gatherings and foot traffic because most people are not idiots and generally took more care than usual (more on this in the next point). So the absence of stay-at-home orders did not mean that economies did well; businesses lost a lot of customers because people chose to stay away from each other.
9) It's increasingly clear that disease spread is largely driven by superspreaders. The numbers are far from precise, but something like 10% of infected people cause 80% of new infections, while perhaps 70% do not infect anybody. This is a more extreme 'clustering' than many other diseases. We don't know if there's anything particularly different about that 10% that makes this happen, in terms of physiology or immunology. But this represents an important opportunity: if those superspreading events can be contained, the epidemic may die out by itself. [The following is my speculation] I suspect this is why even weak reductions in population activity were extremely effective in suppressing the disease. And why many places have not seen surges in cases after reopening. When people took the logical step of avoiding the most crowded areas (stadiums, public transportation, bars, restaurants, etc), they effectively prevented a lot of potential superspreading events. I'd like to stress this point: it shows that even weak compliance with distancing recommendations/rules can be immensely beneficial for the whole population. This is worth keeping in mind as the lockdowns are lifted, new outbreaks happen, and plenty of people can't be arsed to obey the resulting lockdown reimposition.
10) As countries reopen, there is going to be intense debate and lobbying about what to allow. Given what we know, crowded places/events with a lot of people expelling a lot of air are probably the riskiest. An incomplete list would be: gyms, sports stadiums, concerts, university dorms & big classes, some places of worship (there seems to be a weirdly high number of reported outbreaks among choirs), nightclubs, some kinds of restaurants & bars. There's some evidence that younger kids don't get infected much and so reopening schools may be less of a concern (only moderate confidence in this claim right now). I expect places of worship will be opened sooner than ideal, so we ought to be talking to religious leaders about how best to manage the consequences of the outbreaks that will ensue.
11) As we reopen, there are going to be new outbreaks. In an even mildly competent world, we'd have built up the capacity to do lots of testing, tracing, and isolation of newly infected cases. I don't think we have done this to the degree needed in a lot of countries. Since we have not done this, a second, poorer option is cycles of shutdowns and reopenings as outbreaks are detected and controlled. Except plenty of societies are barely tolerating the first shutdown, so subsequent shutdowns seem almost guaranteed to be ignored. So what happens instead? I expect we'll see plenty of businesses change how they function for the near future till we have this under control. Some businesses may also start offering exceptions to these restrictions if customers can provide proof of immunity from antibody tests. This will essentially provide extra services to people who have immunity, creating a market for both fake test results and for people to voluntarily get infected. A while ago I mentioned that governments manage this by providing people with official 'immunity passports'. This is understandably opposed by civil liberties advocates, but we might end up with a messy private version of this instead.
12) I mentioned universities earlier and want to expand on this. A combination of factors are going to send a lot of universities - especially in the US - into financial freefall. The risk in crowding lots of people together into classes & dorms, the poorer educational experience of video conferencing, high tuition fees, immigration restrictions cutting off high-paying foreign students. and the inevitable recession-driven slashing of government funding (in the US) are all going to hit the bottom line. Also, universities have apparently been mismanaged to the extent that many do not have the financial reserves to weather these storms (if they can't even manage money, why on earth did we let the corporate world start running them?). The famously large endowments are not (according to university spokespeople) funds that can be used to manage the crisis, because money willed to the university comes with specific conditions attached. Using them to tide over general budget shortfalls apparently violates a bunch of legal agreements, ones which universities are less happy to break than say, union-negotiated job contracts and pension liabilities. The biggest universities will probably manage somehow, in part by taking in students who might otherwise have gone to lower-rung universities. At least some of those lower-rung universities may have to have to radically change or close down. Hopefully some good will come from the necessary experimentation. Teaching in the lockdown has kicked many of us out of our rut and may help improve what we do. With more support and practice, we could perhaps be teaching more students, better. But it seems likely to be a bleak few years to be an academic, especially an early-career one.
13) I've argued previously that you should ignore the headline of the day, because most science papers offer provisional results, the media communicates science badly, and you will end up misinformed. I stand by that, but feel obligated to talk about one study in the Lancet that claimed that hydroxychloroquine does not help with COVID and actually kills people instead. For obvious political reasons, this story spread like wildfire. Well, there are massive problems with that study, and not of the usual scientists-disagree-about-how-to-interpret-everything kind. There's an extremely good chance that it is a hoax and the data completely made up. Here's one valuable critique you can read: http://freerangestats.info/.../implausible-health-data-firm . Note that this does not mean that hydroxychloroquine is actually good.
14) We're likely to see more protests of all kinds soon, and not just in the US. These protests are extremely likely to spread the virus. If you argue that the goals of a specific protest are more important than the possibility of spreading the virus, be prepared to listen when a similar argument is made by those protesting for goals you dislike. Dismissing their arguments out of hand will lead to charges of hypocrisy, and people who disagree with you politically will have less reason to listen to your advocacy on any topic. In any case, we should be preparing for outbreaks in all these cities where protests happen. The sad fact, though, is that contact tracing is going to be a much harder sell when protestors view it as a way for authorities to track down and suppress political dissent. Contact tracing that maintains privacy may be vital here.
15) Slow vaccine progress continues to be made on a variety of fronts. Two of the best initiatives on that front are those by the Gates Foundation and Operation Warp Speed by the US government, both of which are spending billions to build capacity for vaccines that we do not have yet. Most of that money will end up being spent on vaccines that do not work. But if one or two work, it could save millions of lives and trillions of dollars. This is the kind of targeted, wise initiative that we need more of, and not just to deal with this virus.
In response to 2 questions about my speculation in point #9 that weak measures may be sufficient to stop superspreading:
(i) about modelling rare events
A toy model should be relatively simple to implement. If you want to get fancier, here's some resources you might find interesting/useful:
https://www.nature.com/articles/nature04153 (old & general, and already supports the basic intuition)
https://covid.idmod.org/.../Stochasticity_heterogeneity... (very new, specific to COVID)
https://epidemicsonnetworks.readthedocs.io/.../index.html (Python module for modelling epidemics on networks)
(ii) explaining my intuition behind why weak measures can stop superspreading:
I'm going to invoke some realistic numbers for this based on what we now know about COVID:
Imagine 10 people are infected. 7 of them do not pass it on; actually, let's say they *cannot* pass it on, for argument's sake. Of the remaining 3 people, 2 pass the infection on to 1 other person each. Let's say this is to a family member or someone they are closely associated with. The disease spread by these 9 people may be unaffected by distancing & lockdowns, but it only results in 2 infections.
For the disease to continue to spread, the remaining 1 person has to infect more than 8 people, since the initial 10 has to infect more than 10 or it dies out. In ordinary times, this may happen when they encounter crowds at the office, or church, or a restaurant, or on the bus, or a concert, or so on.
When people are distancing and the most crowded areas are shut down or avoided, this one infective person encounters fewer people and at lower densities. This makes them much less likely to pass it on to more than 8 people. Even if people are not strictly following the rules or the lockdown is quite mild, they may infect only 4 or 5 more. The newly infected cohort is 7 people (2 + 5), which is lower than the previous cohort. Since the same logic applies to them, over time the number of infected dies down and goes to zero.
Basically, preventing a few people from each infecting 10 people is easier than preventing lots of people from each infecting 2 people.
In response to a question about a Medium article about Covid being a 'blood-vessel disease':
It does seem to be a plausible mechanism, though the Medium title is hyperbole. There's been a couple of months of reporting on this, and the story does seem to be gaining in prominence (see this from yesterday, for example: www.sciencemag.org/news/2020/06/blood-vessel-attack-could-trigger-coronavirus-fatal-second-phase )
There's an odd angle to this story that I spent some time on. The Medium article cites only one scientific paper, so I took at look at it. Bizarrely, it shares a couple of authors with the hydroxychloroquine paper that appears to be a hoax (the one I wrote about above in point #13). That made me worry about how reliable this paper was, so I dug into that a bit. As best I can tell, the shared co-authors were not the main players in the (alleged but very likely) hoax. I'd guess they were innocent; their other co-authors on the dodgy paper were from a company that seems to have fabricated the data. It does call these doctors' judgement into question, though.
In response to a question about the role of population density and infrastructure:
I agree that density & infrastructure are likely to be very important, and probably a major reason why New York was hit so horribly. And yeah, that also implies huge differences between states, which is likely to make co-ordinating policy tougher. Low-density states are generally Republican and already relatively sceptical of scientists. If they are fortunate and escape big outbreaks, they are likely to become even less supportive of public health efforts, including vaccination when that becomes possible.
Europe basically suspended Schengen when it closed all borders, and each country chose its own path and felt the consequences of its own decisions. US states will be pursuing different strategies but won't be able to close borders, which makes the outcomes dependent partly on the policies of their neighbours. I expect this will cause a lot of friction.
In response to a question about the WHO covering for China:
I'm no fan of the Chinese government, and I think the WHO has taken some pretty lousy political decisions in the past few years (it screwed up on Ebola before this). I also agree that the WHO has deferred too much to China on this. But much of this popular story you refer to seems to me to be an effort by governments to shift blame and excuse their own negligence.
China contributes a relatively small portion of its funds. You know who contributes more? The US. And the UK. And Germany. And Japan. And the EU. And the Gates Foundation. Even goddamned Rotary International pays more than China.
Of course, maybe money is not the main factor. After all, the director-general was elected with support from China. So who runs the WHO? It has 194 member states and an executive board of 34 members that is chaired by a leader that rotates geographically. The chair probably doesn't have much power, but FWIW, it was led by Japan till a week ago - hardly a shill for China. Where's the US in all this? Oh, it's not bothered to nominate anyone to its executive board seat, which has been left vacant for years. This is consistent with the US government's choice to ignore or weaken pretty much every international organisation. If the US chooses to ignore these organisations, is it any wonder that other entities increase in influence, if only by virtue of being at the table?
The WHO made statements in January and February that were stupid and wrong, even given only the information available publicly. But you can call it a strategy: they were probably trying to coax China into giving their experts access to Wuhan to study what was going on. To some extent it worked, China did let them in. It was not worth the damage caused by the misinformation. But the WHO has no power to force any government to do anything, so they probably thought mollifying the Chinese leadership was the best option they had. Especially when the only powerful country that could back them in this fight, the US, was in absentia and busy praising the Chinese leadership for their efforts.
Most importantly, however, plenty of countries did get the obvious message back in January and February and took action. Vietnam has had 0 deaths and 300 cases. Mongolia has had 0 deaths and 200 cases. These are relatively weak, poor countries that share a border with China. They simply jumped into action immediately, based largely on information that you could read in any international newspaper at the time. Even Kerala had a plan in place in January.
So whatever influence China may have at the WHO, most of the lives lost have been because of the incompetence of authorities in the US and Europe. This was not inevitable. There was more than enough information available in January and February to take action, and for reasons that I do not understand, most governments and health authorities twiddled their thumbs.
The WHO is a convenient scapegoat for their failures to save the lives of hundreds of thousands (likely over a million before this is over) and the livelihoods of hundreds of millions.
Coronavirus news #5. Developments have been slow, so this sort of aggregates the last ~3 weeks. I don't think any of it is out of date, but it's possible. Please point out my errors. And let me know if there's a question you want investigated. Several weeks without human contact and I now have no idea what is common knowledge and what isn't.
1) After the shock of exponential growth, we seem to have been in a bit of a holding pattern for the past few weeks. Reported deaths per day have even started to decrease in most places. But the decrease is slow, and we're still losing 5000-6000 people per day, not to mention identifying ~70,000 new cases. That's about 4% of the number of people who normally die everyday worldwide. This is not as bad a catastrophe as we feared it might develop into, but it is a lot of people. Especially since this is the death rate after locking down and taking a torch to global economies, an emergency measure that is unlikely to be extended much longer.
2) The good news is that several countries have avoided the explosive increases we were seeing in March, and some have actually steadily reduced the total number of cases. Sweden got perhaps too much attention, but it is interesting that the mild action they went with was sufficient to at least stabilise the rate of increase (the active cases increase steadily there). Switzerland has done better, with a month of steadily decreasing total cases. And many developing countries have done much better than avoiding the worst-case scenarios. India slowly increases in cases (which is worrying) but it's far, far better now than scenarios that seemed possible to me; I feared bodies piling in the streets and social breakdown. Other countries such as the US have done considerably worse in containing the problem, despite having many advantages.
3) This brings us to the inevitable question: why? Why did some countries have massive outbreaks and others that seemed equally or even less prepared escape them? A month ago (seems like years) I wrote that there were several theories, ranging from the plausible to the wild: local temperature & humidity, degree of contact between generations, very small numbers of 'superspreaders', history of BCG vaccination, smoking preventing infection, and more. Amazingly, none of them has really accumulated much supporting evidence, and several have been weakened by new data. What we know well is pretty much the same as a month and a half ago: it's bad for old people. And having other health problems (respiratory, heart, obesity) probably matters; it seemed very plausible a month ago and I haven't really seen much more about this that changes my mind one way or the other.
4) One important detail is that a huge number of deaths seem to have happened in old-age/retirement/nursing homes - possibly as much as half the deaths in Europe. These types of homes are rare in developing countries, where populations are younger and the elderly typically live with their families. So the concentration of old people, perhaps along with poor health protocols for their caregivers, is likely to have been a massive contributing factor. Other major outbreaks, especially in the US, seem to have happened in prisons and meatpacking facilities.
5) In many countries, we are still not testing enough, and the testing we are doing is not designed well enough to help us understand the broader picture. So months into this pandemic, we still don't know with much precision how many cases there are out there, or how deadly the virus is. As a result of this poor testing, the stabilisation at 70,000 new cases per day may partly reflect the fact that testing has stagnated.
6) Testing was only one part of the solution that epidemiologists have been banging on about for months. The others are tracing (finding people who came into contact with infected people) and isolation (separating infected and at-risk patients from the rest of the population, sometimes including their families). As I've said, testing is in bad shape. And best I can tell, tracing and isolation are virtually non-existent in much of the developed world. Lockdowns will help temporarily but cannot be sustained indefinitely. I don't understand the lack of tracing and isolation efforts. This is yet another colossal institutional failure.
7) Forget contact tracing apps for now. Most people are aware that the basic versions that many governments want give away far too much privacy and are ripe for abuse. There are solutions to this, and Apple & Google have done really great work in pushing for privacy preservation despite pressure from governments (Europe fought against privacy!). But there are huge problems with even the versions that protect privacy. For one thing, protecting privacy means that the system is extremely vulnerable to attack by bad actors - trolls, rival companies and countries, and so on. It requires an improbably large fraction of the population to use the apps for them to work. And because of the way they are designed, there are simply too many false positives and negatives; people will soon ignore the warnings as a consequence.
8) So what would tracing and isolation look like? Massive amounts of human effort. It can be done! Forget South Korea, it does not even require much sophistication. The first state in India to get hit, Kerala, has had teams of people track down every person to come into contact with an infected individual and isolated them. They had doctors and counsellors help every affected person. They provided food and shelter for people in need during the lockdown, included hundreds of thousands (millions?) of migrant workers. Kerala has a population of 35 million people, comparable to most European countries and bigger than most states in the US. It's much poorer than either. It's had 4 deaths and presently 37 active cases. And it is not unique. A smaller state, Goa, apparently had teams visit every single household to check on them. It's a major tourist destination, and it has zero active cases! The US presently has about 7000 people to do contact tracing, for a population of 330 million. That's probably 2 orders of magnitude lower that what is needed. I don't know the situation in Europe and I would love to read about it if any of you have links you can point me to. But I suspect it's not good. I really don't understand why this is not being done, especially when there are large numbers of young people without jobs who would gladly help in this effort and are much less susceptible to infection themselves.
9) Shutdowns have been met with resistance in several countries. To be fair, some of them seem to have stabilised the situation enough that a lockdown may at present be causing more suffering than not. So we should expect some reopening soon. When this happens, we should expect a second wave in most countries (except for those like the US that are still working on their first). Without the tracing and isolation infrastructure, this might spiral out of control once again, and require subsequent lockdowns. I fail to see how any of this is supposed to save economies, especially since people voluntarily stay home even before lockdowns are declared. Stopping the damn pandemic is really the only path back to normalcy.
10) This pandemic has brought out some of the worst tendencies of the press, so I'd very strongly urge you not to pay attention to the story of the day. With rare exception, journalists don't have the training to understand and criticise science, so we have a lot of glowing reports about the latest drug study (Remdesivir! Hydroxychloroquine!) or estimate of disease incidence. Most of these studies are not good enough to pay attention to. Almost no study you will hear about is done well enough and at a scale that will substantially shift the present consensus. At best they will prove to be the basis for further, better studies. If you're going to try and track this sudden profusion of studies, you will exhaust yourself, give yourself false hope, and likely end up misinformed. The normal progress of science involves most studies having substantial weaknesses, and there is plenty of disagreement and argument around them. You don't hear about it because it doesn't make its way into the press ordinarily. Right now, much of the press is reporting the studies based on the authors' interpretations without offering you the criticism from other specialists. Or when they quote someone, they don't understand the topic well enough to show you who is more believable - the author or the critic. If you want to follow one science writer, read Ed Yong in The Atlantic.
11) Aside from the press, many health agencies and governments have also done a pretty awful job of communication. They have stressed certainties ("Masks don't work!") when evidence was weak or absent. When subsequent evidence has proven them wrong, they have earned mistrust and enabled the conspiracy theorists. If you want good information, go straight to the sources: epidemiologists are laying it all out for anyone to see on twitter.
12) Speaking of uncertainty: the question of whether people can be reinfected by the virus keeps popping up. We don't know for sure but there's good reason to expect immunity. It's worth keeping in mind two things when you see reports that someone has caught the disease a second time: (i) There are a lot of false negative and false positive tests. When someone is thought to have been reinfected, it's almost certainly because the test that declared them recovered was a false negative. (ii) Immunity is not perfect. If your probability of catching the disease goes from say 30% to 0.03% (warning: made-up numbers), I would call it strong immunity but you will still have a lot of people catching the disease a second time.
13) You've seen or are going to see big fights over how many people died because of the virus, because of the implied culpability associated with higher numbers. Already, there's plenty of people who are suspicious that deaths are attributed to COVID without testing the corpse. But why would we waste our limited tests on a dead person? And people die for a combination of reasons and it's frequently impossible to say that the precise reason was previous lung problems or heart disease and not COVID; in reality, the combination of factors led to the death. Also, plenty of people are dying without having been checked, so frequently we have no idea. How do we solve this problem? The most reasonable solution is to compare how many people are dying right now with the 'normal' number of people that die at this time of year. We usually define 'normal' by taking the average of many years because some years are better and some are worse. This is not perfect: there are fewer traffic accidents now, less pollution, less flu transmission because of lockdowns, and other factors. But it's the best simple answer. There are clever ways to adjust for the other factors, but they are complicated and the conspiracy theorists will accuse the scientists doing those adjustments of cooking the books. Just be aware that there's a simple and pretty reliable answer that you can calculate yourself.
14) We're now seeing a profusion of epidemiological models coming out. Keep in mind that for the most part they are not designed to tell you exactly what is going to happen. Instead, they tell you what is likely to happen if societies take different actions, so that we can decide about how best to respond. Any change we make (lockdown, reopening, voluntary distancing) changes the situation and makes the model predictions inaccurate. Criticising modellers for being alarmist when we have taken the actions they recommended to prevent their predictions coming true is both ridiculous and exactly what I said would happen in the first of these posts. Please fight these lousy critiques.
15) I've talked about different types of models and expressed my preference for mechanistic epidemiological models (specifically SEIR models) over phenomenological/statistical models (like the IHME model). I used to think that the basic versions I was taught had unjustifiable assumptions that make them ill-suited to making COVID predictions. But I'm now leaning towards the view that many of the complexities they ignore (variation in population density, number of people contacted, susceptibility, mobility, etc.) are not such a big problem, relatively speaking. The bigger issue is that all the models use parameters that are hard to measure directly, so instead we have to infer them from the very bad data we have on reported cases and deaths. None of the models is going to provide a precise picture of the future because of all these uncertainties; even the very best is likely to be wrong about the time of peak, total number of deaths, and more. But some are still better than others and if you're interested in predictions, I'd tentatively recommend https://covid19-projections.com/, https://github.com/ryansmcgee/seirsplus, https://mr-sir.herokuapp.com/main, https://epiforecasts.io/covid/posts/global/, https://covid19-scenarios.org/ as good resources. Keep in mind that ultimately, they all rely on data for their inputs. To the extent that the data has problems (and it does), this makes the model predictions have problems too.
16) We seem kind of stuck till we get a vaccine. The most informed voices are talking about a 2-year timeline for this; the fastest previous vaccine developed took 5 years. I have no expertise in this but if I had to bet, I think it will be done faster. That's because this situation is unprecedented and there are incredibly strong incentives at play. By dusting off every possible angle of attack and technology, skipping a lot of regulatory and testing hurdles, essentially throwing a million darts at the board, I imagine we will achieve this faster. You should not trust me on this, I cannot really justify this opinion.
17) That said, developing a vaccine is very different from deploying it at the scale of billions of people. So far, much of public health infrastructure has failed quite miserably. Much will depend on whether this shock enables the bureaucratic problems to be fixed in the next few months. But institutional knowledge and expertise is not easy to accumulate rapidly.
18) We don't know yet, but it seems likely that people who have recovered will suffer long-term health consequences. The toll from this pandemic is even higher than the body count.
Why I do this
I am not an expert on Covid, viruses, or vaccines, but I am a scientist with relevant training. I believe we have a responsibility to clearly communicate science to the public, especially in emergencies. So I started to write summaries of Covid developments on facebook in March 2020 to help friends and family understand the situation as it unfolded. This is an archive of those posts (created much later).