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Wednesday, March 18, 2020

Hope about coronavirus

Briefly:

  1. The bad news first.

    Tim McGrew makes a great point here. This can't go on forever. It'd cripple us (if not worse) as a nation if it did.

  2. Peaks and troughs.

    Right now the prediction is the coronavirus (i.e. SARS-CoV-2/COVID-19) will peak in May, then start to decline after that. (However, to be fair, some argue COVID-19 could have an endemicity and seasonality to it, which in turn could mean more outbreaks and even epidemics again even after it peaks and declines.)

  3. Herd immunity.

    If the coronavirus infects enough people, which it looks like it will, and the vast majority recover, which is already the case, then we as a population would develop a degree of herd immunity to it. So this would delimit the coronavirus to a significant degree. Sure, there might be outbreaks in certain hot zones (such as with measles outbreaks over the last few years), but not an epidemic that consumes the entire nation like people fear now. It goes without saying it's comparatively much easier to control outbreaks than epidemics.

  4. Vaccines.

    Currently it looks likely we'll have a vaccine within 1-2 years. Yeah, that's a long time away. Still, it's encouraging to know the NIH and Moderna started Phase 1 clinical trials a couple of days ago. Hopefully it'll succeed. But even if it doesn't, there are many other companies hunting for a vaccine as we speak. And I believe clinical trials are being accelerated for the coronavirus. There are no guarantees in life, but the likelihood of an eventual coronavirus vaccine is more than plausible.

  5. Antivirals.

    In the meantime, I've pointed out we're trialing different therapies. Antivirals. Such as remdesivir. Also chloroquine. Likewise tocilizumab (atlizumab). So many others. For example, see my post about what Stanford is doing here. All of these look quite promising.

  6. Antibodies.

    Short of vaccines or antivirals, I've mentioned there's passive immunity through transferring the antibodies of those who have recovered from coronavirus to others. See here for instance. This is already available. We could use it right now. We would need to scale up and deal with logistics (e.g. blood banks), but the medical therapy itself is available today. It'd be something like a monthly injection (prophylaxis) primarily for health care providers, the elderly, and the very sick. This alone could drastically reduce the transmission of the coronavirus.

In short, there's hope. No need to panic.


Edit:

I hadn't seen the following clip (below) before I wrote my post. It's a 2-minute clip of an infectious disease expert on Sean Hannity talking about "this is where America shines" with regard to the coronavirus. He mentions some of what I've mentioned in this post (e.g. vaccines, antivirals, antibodies in plasma therapy) and also alludes to diagnostics (e.g. drive-through testing, imaging) which I didn't mention but is definitely worth mentioning too.

14 comments:

  1. Hawk, while the majority of the COVID-19 focus has (rightly) been on containment, mitigation and disease prevention - although some experts like Dr. Michael Osterholm say such efforts are akin to trying to stop the wind - little if any focus thus far seems to have been applied to those who have recovered, and the post-recovery effects of the disease.

    I've looked into this topic and data seems sparse, but from what I've found some have described the fully-recovered as having permanent lung damage with capacity loss as high as 30%. This is from researchers in Hong Kong who followed a group of 12 patients post-recovery. Hardly a large scale study I realize, but it's more than anecdotal. I also read an article that stated lung scans of post-recovery COVID-19 patients showed damage similar to asbestos exposure, or breathing volcanic steam which literally contains microscopic shards of glass.

    Have you come across anything like this in your research? I'm thinking post-crisis, even after herd immunity levels are reached that there may be serious long-term persistent, irreversible public health consequences to surviving a bout with COVID-19 which could linger well beyond the pandemic.

    I realize your posts have been purposely optimistic, but realistic as well. Thoughts on this?

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    1. Thanks, CD. That's a really good question! I hope you don't mind if I number my responses. I'll start broadly, then try to hone in on your question at the end.

      1. Oh yeah, for sure, most of my posts are intentionally attempting to assuage panic. I'm just attempting to counterbalance the news, social media, and so on (in my own limited way). But I'm probably failing!

      2. At the same time, I do agree the coronavirus is quite serious. I wouldn't want to diminish this. I think there are two opposite but equal errors: the idea that there's nothing to worry about and the idea that there is reason to panic. I think there's a middle road. Of course, it's difficult to navigate the middle road. I'll hear disagreements from both sides. Alas.

      3. I think a big problem is that we're learning about the coronavirus at the same time we're attempting to combat it. The data is coming in fast and hard at the same time physicians and health care providers are attempting to implement best treatment and management therapies. Theory and practice are both informing one another.

      4. It's something of a challenge to know how relevant regional data is to us (or other regions). For instance, South Korea and Italy both have different demographics including health profiles. Same with China. Same with us. In fact, the US itself could be subdivided in terms of (health) demographics. So it's debatable - at a time in which scientists don't have much time to debate - how relevant or to what degree it's relevant to compare (say) data from Hong Kong with data from Milan with data from Seattle etc. Even if we take something straightforward like the mean or median age. Or take obesity. Americans tend to be more obese than Chinese so will this make a difference in disease progression? And so on.

      5. At least to my knowledge, most the studies that have come out around the world haven't been random controlled trials which are the gold standard for trials. Rather they've largely been non-randomized, non-blinded, non-peer reviewed, and have other methodological limitations and biases (e.g. lack of analysis in intention to treat). Of course, that's for good reason, because we're in the midst of a pandemic, and scientific and medical journals are simply trying to get data out there as quickly as possible for everyone. So on the one hand it's good (and in many ways amazing) there's been such a plethora of publications with necessary goals like trying to help inform clinical decision-making, but on the other hand most of it is (shall we say) limited in nature or scope.

      6. All that said, I haven't looked into the post-recovery effects of coronavirus myself, but I think it's safe to conclude what you've already concluded: (a) there's a paucity of data, (b) what's out there is very likely limited, and (c) it'd likely be a challenge to connect what's available now with what clinical prognosis might look like for someone who has recovered.

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    2. 7. I can say the main system that's been affected by the coronavirus is indeed our lungs. For example, the majority of people who end up dying from coronavirus tend to die from ARDS (acute respiratory distress syndrome). Basically ARDS is when the lungs are so filled up with fluids (edema) that it's super difficult for people to breathe (hypoxemia). This "looks" similar to congestive heart failure, but it's actually not caused by the heart (i.e. it's non-cardiogenic pulmonary edema). So yeah, I think the majority of coronavirus cases that end up dying die from ARDS. Yet this also means people who recover (if they've recovered from the ICU/vent) would likely have recovered from ARDS. However, whether or not ARDS leaves long-term damage on a person in turn depends on a host of other factors. Such as their age and if they have other underlying diseases. So we'd have to distinguish between these, but the problem is it would take time to do a proper study, and of course we're in the middle of a pandemic and ICU physicians are too busy trying to keep patients alive that most aren't able to engage in the kind of research we would need to show this.

      8. Of course, I don't wish to suggest the lungs are the only system injured from coronavirus infection. There are others as well. In fact, we're only very recently learning about how the coronavirus can manifest in the gastrointestinal system in a percentage of patients so it's important to look for presenting complaints about abdominal pain and the like. Likewise this paper was published about a week ago and it set off a flurry of debate. The reason is beause the coronavirus (SARS-CoV-2) has a spike or S-protein that binds to ACE2 receptors on type 2 pneumocyte cells (among other cells like aforementioned GIT cells). This paper argues medications known as ACEIs and ARBs may increase ACE2 receptor expression on cell surfaces. Hence the suggestion of the paper is that patients who are using ACEIs and ARBs, i.e. mainly hypertensive and diabetic patients, might reconsider using ACEIs and ARBs to treat their hypertension and diabetes, in case it does cause their lung and other cells to have more ACE2 receptors, and thus put them at greater risk of being infected with the coronavirus. I personally think there needs to be way more reliable data before anyone can draw that conclusion, otherwise we're going to have lots of patients with high blood pressure and diabetes who may stop taking their medications out of fear of the coronavirus, when that could likely seriously harm them if they stop. Anyway it's hotly debated. But point being, these are other parts of our body that the coronavirus could damage.

      I hope that was at least somewhat helpful.

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    3. "lung scans of post-recovery COVID-19 patients showed damage similar to asbestos exposure, or breathing volcanic steam which literally contains microscopic shards of glass."

      Just wanted to add:

      As I mentioned above, this (SARS-2) coronavirus can cause ARDS. That's obviously bad. ARDS would require transfer into the ICU. The ICU takes care of the sickest patients in the hospital.

      Let me take a step back. If someone gets coronavirus, they could range from mild to severe in terms of how bad their coronavirus infection is. They could be (we're told) asymptomatic. They could have a milder form of the coronavirus where they can stay at home and recover. They could be more serious and require hospital admission to one of the wards. The very sickest would be admitted into the ICU.

      However, even within the ICU, there are varying levels of severity. I mean, of course, coronavirus patients would have to be quite severe just to be in the ICU, but I mean in terms of ARDS. If someone has ARDS due to the coronavirus, they can have varying degrees of severity within ARDS too. That is, ARDS can be in early or late phases or stages. So two different patients could get ARDS, but one patient's ARDS doesn't do as much damage as the other patient's does.

      If there is enough damage and even loss of the lung cells (i.e. type 2 pneumocyte cells) in ARDS, then it can indeed lead to scarring and interstitial fibrosis. That might be what you're hearing about when you hear about things like "microscopic shards of glass". It's not that the lungs are literally cut up by shards of glass. Rather it's a radiologic finding known as "ground glass opacities" on CT scans of the lungs of patients with ARDS.

      At the same time, it's possible some coronavirus patients with ARDS may have complete resolution. That's typically in less severe cases.

      By the way, phhysicians have long been taking care of patients who develop ARDS. ARDS isn't unique to this coronavirus. ARDS can be caused by other things too.

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    4. Good and helpful thoughts, thanks!

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    5. Hi Coram Deo! The following Twitter thread is kind of related to your question. It starts with: "Let’s talk about what happens if you get COVID19 and recover."

      https://twitter.com/NAChristakis/status/1240689959645753344

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  2. ///In fact, we're only very recently learning about how the coronavirus can manifest in the gastrointestinal system in a percentage of patients ...///

    Hence the need for additional toilet paper ... 🙂

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  3. As major news outlets like the New York Times have updated the number of cases of COVID-19 and confirmed deaths from it, a new trend has emerged: the death rate, measured as the number of deaths divided by the number of cases, is falling. 

    Six days ago, on March 12th, there were 36 deaths caused by the virus in the U.S. out of a total of 1,215 cases. As of this writing on March 18th, there have been 121 deaths out of a total 7,047 cases. 

    That is a drop in the death rate from 2.96% to 1.72%. 

    This is encouraging, as the U.S. death rate so far has been substantially lower than in China and even lower than France and the U.K. There has been much talk about policy responses to stem the spread of COVID-19, but school closings and social distancing should mostly affect growth in the number of cases, not the deadliness of the disease itself. 

    Why would the U.S. death rate fall so much over just a few days? The answer is that as more people are tested for the virus, the death rate falls because it becomes more accurate.

    And the most accurate data are likely coming from Germany, which arguably has had better testing than any other country. Germany also has the lowest death rate, at just over 0.1%. If that number sounds familiar, it is roughly the death rate from the 2018-19 flu season in the U.S.



    https://www.aier.org/article/the-us-coronavirus-death-rate-is-falling-and-germanys-more-so/

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    1. 1. If accurate, that's good news about Germany. It makes me hopeful.

      2. However, to be fair, we can't necessarily expect what's been uncovered by testing in Germany will be what will be uncovered by testing in the US. Maybe it will be (I hope), but maybe it won't be. In other words, extensive testing of the US population may or may not reveal the same patterns of disease as in Germany.

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    2. Why would the virus respond at different rates in different places? Assuming first-world countries like the US and Germany and Italy all have the same information, such things as the same kinds of sanitary practices, etc., and offer comparable treatments?

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    3. "Why would the virus respond at different rates in different places? Assuming first-world countries like the US and Germany and Italy all have the same information, such things as the same kinds of sanitary practices, etc., and offer comparable treatments?"

      Ah! But there's the rub. The US, Germany, and Italy aren't necessarily all the "same"! For example, they have different demographics including health profiles (e.g. Italians tend to have a higher median age, it looks as if the elderly in Italy may even have had more comorbidities prior to the coronavirus, Americans tend to be more obese at younger ages). For another, public health systems of each nation are quite different (e.g. some nations have primary care systems, other nations do not but in fact communities interface directly with hospitals without primary care services to serve as a kind of buffer between the community and the hospital systems so hospital systems can be easily overwhelmed in such cases). Just a couple of things, but there's a lot more that could be said.

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    4. To put it another way, the virus is more likely to harm someone who has a weaker immune system than someone who has a robust immune system. Same virus, but what it does is different in different sorts of people.

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    5. But still, death rates across age groups, for example, would be the same (again, assuming all things being equal) -- and I can acknowledge that Italy has an older population, but the death rate for 80+ in the US would be the same for 80+ in both Italy and Germany (and of course, allowing for differences in the quality of health care).

      So if the death rate in Germany is most accurate (because of best testing), then (again, adjusting for the quality of the health care systems), even Italy *could* bring its 80+ death rate down to similar levels. And of course, the US, with (supposedly) the best medical care in the world, ought to be able to match those numbers. Correct?

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    6. "assuming all things being equal"

      This the very point of contention! Are things necessarily equal? Maybe, maybe not!

      "and I can acknowledge that Italy has an older population, but the death rate for 80+ in the US would be the same for 80+ in both Italy and Germany"

      As I said, it looks like the elderly in Italy may have had more comorbidities prior to the coronavirus. Obviously we don't know for certain since the whole situation is ongoing and evolving. However, at the very least it looks like a possibility. If that is the case, then an 80 year old Italian would be more sick than an 80 year old American on average. Obviously the virus would likely be more of a threat to a more sickly person than it would to a healthier person. Hence the same virus could have a different impact on the same aged populations.

      "So if the death rate in Germany is most accurate (because of best testing),"

      Of course, all things are relative. Germany may have done more testing than most other nations in the world (I don't know but I'm just assuming it's true), but that doesn't necessarily mean Germany has done sufficient testing.

      "(again, adjusting for the quality of the health care systems),"

      That depends on how we "adjust" for the differences in health care systems! We can't simply say "adjusting" for the differences without specific details. Otherwise it's just a throwaway line.

      "even Italy *could* bring its 80+ death rate down to similar levels."

      1. That depends on a whole host of factors. Such as what its physicians and other health care workers are doing on the ground. Right now, they're working like crazy day and night to bring things under control. Heck, even China has sent doctors to Italy to try to help. So yes, the hope is that Italy can bring down the number of people dying from the coronavirus, which again they're desperately trying to do, but it's going to be an uphill battle.

      2. To put it another way, more morbidly in fact, I guess once the coronavirus has either infected enough Italians and/or killed enough Italians, then it'll likely slow down. Then it won't kill as many. However, I highly doubt most people would think this is a good way to stop the spread of the coronavirus!

      "And of course, the US, with (supposedly) the best medical care in the world, ought to be able to match those numbers. Correct?"

      Again, lots of issues to discuss. But I'll just focus on one. The initial purpose of testing is to identify clusters of those infected, track down their contacts, and isolate and treat them and their contacts. If this is done well, then the disease can be contained. Take Seattle. When the coronavirus hot zone was limited only to Seattle, it was definitely manageable. However, after it started to spread across Washington state, it became increasingly difficult to contain. Simply because of too many people. That has nothing to do with how fantastic our medical are is. Rather that simply has to do with overwhelming numbers.

      Or think about it this way. We have the best military in the world. However suppose like 50% or 75% of the entire world including Russia, China, North Korea, all the Mideast, many Latin American nations, many African countries, many Asian nations all went to war against us at the same time. No matter how spectacular our military is, we just don't have the manpower or resources to fight 50% or 75% of the world's population.

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