![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
sidereaCanonical link: https://siderea.dreamwidth.org/1832343.html
0.
Protecting yourself from Covid requires understanding Covid correctly. One of the things that you should understand about Covid, and any infectious illness, is the dose-response relationship.
That's the fancy highfalutin' medical way of talking about a very simple idea you already have and use all the time: the bigger a dose of something you get, the stronger its effect on you.
This is usually true of medicines, of course, but it's also true of poisons. Consider lead poisoning, for example. Medical science tells us no amount of lead in the bloodstream is safe. But, as you're probably already aware, even so, having more lead in your blood is worse than having less. Somebody who has only 5 µg/dL of lead in their bloodstream is definitely lead poisoned, but they're in much better shape than somebody who has 500 µg/dL.
It turns out viruses and other infectious microbes are like poisons. Research strongly suggests viruses also have a dose-response relationship: generally speaking, the more of the virus you have inside of you, the worse your symptoms are and the greater the threat to your health.
When you think about it, that's not really a surprise, is it? It makes a lot of sense. If viruses make us sick, then people with more of a virus in them would be likely to get a lot sicker.
A lot of people right now are thinking of infection with Covid as a yes/no sort of thing: either you're infected or you're not. This is not true. What the reality of the dose-response relationship means is that you should be thinking of Covid (and all infections, whether viral, bacterial, fungal, or otherwise) like getting poisoned. Obviously, the best option is not to get poisoned at all. But if you do get poisoned, your next best choice is to do what you can to minimize how much poison is in you.
Now the big obvious difference between being poisoned with something like lead and contracting a viral infection is that viruses replicate. However much lead poisoning you get is how much lead poisoning you have, but if you get a small amount of Covid, left to its own devices it will rapidly turn into a large amount of Covid.
But the less obvious difference is that our bodies "know" that about infections: our bodies are built to deal with replicating attackers such as viruses. Our bodies have this whole complicated immune system for actively fighting off microbes that replicate. When some microscopic foreign invader probes our bodies' defenses or breaches them, our bodies go to war against that thing.
We do not survive encounters with such microbial attackers without our bodies mounting an effective defense against them. This is what it means to "clear" a virus. Viruses don't just give up and go away on their own. They don't just stop attacking us, and they don't just stop replicating, because they're dumb and they have no off switch. They can't. If they stop, it is because they are stopped. And the only thing to stop them is our immune systems, whether acting on their own, or with the assistance of medications.
These two facts together make the case only stronger for trying to reduce or at least attenuate the amount of Covid in you if you catch it: how much Covid you have at one point will not be the amount you have later if you let it do its thing. Left to its own devices, a little Covid becomes a lot of Covid. And the more Covid there is in you, the worse off for you and the harder it is for your body to get rid of it, the more likely your natural defenders, your immune system cells, will be overwhelmed on the field of battle.
As the Mukherjee article says, explaining why it should be that higher doses of a virus would cause more severe illness:
Remember the expression, from back in the early parts of the pandemic, "flatten the curve"? The idea was we could – and should – protect hospitals from being overwhelmed with Covid patients by trying to keep from becoming one. Masking, socially isolating, and doing other things to protect our individual selves was something that also protected society, because the more people managed to keep themselves from contracting Covid, the slower the spread of Covid would be in the population, and the fewer Covid patients there would be who would need hospital beds. The expression "flattening the curve" captured the idea of how slowing infection is really helpful to defeating it, because it gives that which fights against it a fighting chance. It gives the cavalry a chance to arrive and save our bacon.
It turns out what was true for whole societies is just as true for our individual bodies. What was true for individual people catching Covid is true for individual cells getting invaded by SARS-CoV-2, the virus that causes COVID. If we can flatten the curve in our bodies – the growth-curve of Covid – it helps us fight off Covid. In the same way Covid spreads through a population with an exponential growth curve, Covid spreads through a body with an exponential growth curve. That's the curve we're talking about flattening, whether to give hospitals a chance to keep up with the rate of infection in a population, or to give your active immune system a chance to kick in and fight the infection off. Slowing the spread of the virus within our bodies buys our immune system time to come to our rescue.
1.
It may help to reflect on how viruses actually operate. A virus is kind of like a little chemical machine, sort of like a microscopic drone. It floats around (passively – it has no way to propel itself) on the air or in a fluid hoping (not that viruses can hope, but you get my meaning) to run into the cell of a living being. Like us. We're made of cells, which are little tiny sacks of fluid; these sacks are made of protein and the fluid has floating in it the chemical machinery to operate the cell. The virus has things on the outside of it that you can think of as kind of like infinitesimal chemical keys that correspond to little chemical locks on the outside of the cells of living things like us. The virus bumbles around hoping to bump into a cell that has a wee little matching chemical lock on the outside that its key fits. And when a viral particle finds one they can open, they invade it.
The bad news for us about Covid is that many different types of cell in the human body have a chemical lock on them called the ACE2 receptor – and Covid has the key to that lock. Covid actually has the keys to several locks that we have on the cells of our bodies, it's just that one's really common in the human body.
When the virus unlocks the cell wall, it squirts its own innards into the cell's fluid. This is the chemical machinery that runs the virus. Once inside the cell, it hijacks the cell's own chemical machinery for running the cell. So then instead of the cell manufacturing the proteins that build up the cell so it can grow or make baby cells, the inner chemical machinery of the cell taken over by the virus is put to the purpose of making copies of the virus. Eventually the the cell is so full of copies of the virus, it bursts open, scattering the virus to other nearby cells – and then the cycle repeats, only more so.
This is how viruses reproduce. They have no other way of reproducing. Like the cuckoo laying its eggs in other birds' nests, viruses don't raise their own children: they require the cells of other beings to reproduce themselves.
There's a bunch of things to notice about this process.
It's a destructive process. When the virus invades a cell, that cell's a goner. That's why infections are typically quite irritating – causing sore throats, chapped noses: the virus is rupturing the cells that make up the linings of our upper windway, shredding the tissue that is infected, with microscopic tears. This is also one of the main ways Covid kills: by damaging the linings of the fine blood vessels of the lungs, which leads to blood clots and swelling which clog them, stopping blood getting through so it can't pick up oxygen from the lung and distribute to the rest of the body.
It's an exponential process. Each time a virus particle hijacks a cell, it makes many, many times more copies of itself, so the amount of virus in the body grows very fast, and the rate of growth gets faster the more it grows, like a snowball picking up speed as it rolls downhill turning into an avalanche. A virus increases its own chance of replication each time it replicates. A cell full of virus bursting open is like a burning tree exploding in sparks, spreading a wildfire to even more trees; the bigger the wildfire gets, the faster it spreads.
This is why it is so useful to nip it in the bud. Exponential growth is ferocious, so it is both easier and more effective to stop an exponential process earlier rather than later. It is easier to quench a spark than a forest fire.
This is the fundamental premise of Paxlovid. As you probably know, Paxlovid is a medication for Covid, and the official instructions for using it are that it has to be started within 5 days of the start of symptoms. That's because the entire way Paxlovid works to help you beat Covid is that it prevents Covid virus from replicating. Its active ingredient is nirmatrelvir, a chemical which sabotages the cellular machinery in the cells that Covid invades, such that the copies of the virus that an infected cell makes no longer have the key to unlock other cells. The infected cell will still explode scattering copies of Covid – but they're defective copies, they can't infect more of your cells. (source)
Obviously, it works imperfectly, and some Covid might still manage to reproduce, and the distribution of the drug throughout your body so that all of the cells in it have it to work with is not instantaneous. But even so, at the very least pruning back the amount of Covid so radically flattens the curve – it slows the growth of Covid virus in your body, so when your body's active immune system finally kicks in, there's less Covid virus in you for it to have to try to destroy than there would be without the medication, allowed to proliferate unchecked. And ideally, pruned early, the virus hasn't had a chance to spread to more inner parts of your body that are more vulnerable to it (like the tiny arteries of the lungs) or, worse, gotten into parts of your body in which it can hide from your immune system (like your brain).
And that's why you have to take Paxlovid in the first five days of symptoms: to throttle Covid virus' growth early, the better to keep it from completely running wild in your body. Since what Paxlovid is protecting you from is sheer number of copies of the virus in your body, if you don't take it till after five days, there's not a lot Paxlovid can do for you, because by that point you're pretty much overrun with the virus. And if you have a normal immune system, by about the fifth day your immune system is as awake and involved as it's going to be, so there's no particular thing to delay for.
(That's the reasoning for the official guidelines, but given what I've explained, I bet you can see some of the cases for taking a second or later course of Paxlovid, especially in the immunocompromised. It also explains why sometimes there's rebound Covid after Paxlovid: body hasn't finished fighting it yet, and there's still some virus around, and so long as there is some around it will start to multiply.)
The other important thing to notice about the replication process of a virus such as Covid is that it's a mechanical process. The actual Covid virus particles have to actually bump into cells that they can infect, or they can't get up to any trouble. Anything that keeps viral particles from latching onto cells and hijacking them prevents them from reproducing, and slows the virus's roll, flattening the curve.
This is the obvious theory as to why we get runny noses when we get sick: that it's an evolved defense against dangerous microbes like viruses, that works by simply flushing them out of our noses with snot. Also sneezing when we get sick expels things, including snot full of viruses, out of our bodies. Coughing does the same thing for our throat and lungs.
When you think about it, a lot of the things we already know that help don't just help because they prevent catching Covid at all. They also mitigate how much Covid you get if you get Covid. For instance we wear masks in the hopes they will prevent any viral particles from coming into our mouths and noses where they can latch on and start replicating in our bodies. But even when masks don't work perfectly, and Covid particles get through anyways, the masks cut down on how many viral particles get through to us. This suggests that people who get Covid despite wearing a mask would be likely to get less sick than people who caught Covid while not wearing a mask, because they got smaller doses of Covid – and that is what the evidence currently seems to show.
This is discussed in the Journal of General Internal Medicine article "Masks Do More Than Protect Others During COVID-19: Reducing the Inoculum of SARS-CoV-2 to Protect the Wearer", by Monica Gandhi MD, MPH, et al. (2020 Jul 31) This paper was discussed in this popular press article, which notes:
2.
Why am I explaining all of this, since you were probably already wearing masks and ventilating your spaces and using Paxlovid as available? Because there's increasing awareness there are other things that it might be beneficial to do if one catches Covid.
For instance, there is increasing interest in using mouthwashes as a way of getting rid of Covid virus accumulating in one's mouth or throat.
The research into mouthwashes to eliminate Covid virus was initially done in the field of dentistry, with an eye to having a way to make the mouths of patients less dangerous to dental professionals working on them – that is, as a way of preventing transmission. But the dose-response relationship suggests that it could also be helpful for reducing symptoms and shortening the length of the infection.
There's also interest in the use of nasal lavage – literally washing out the insides of one's nose – as a home remedy to fight Covid.
Long before our present pandemic, there was a variety of research into the efficacy of nasal lavage and gargling, even just with simple salt water, to reduce the symptoms of severity and duration of the common cold. I understand there's not very much of it, and it's not very high-powered, but it's generally promising.
For instance, just a year before our present pandemic started, a small research study was done on whether nasal lavage and gargling reduced the length and severity of the common cold. 2019 Jan 31: Nature Scientific Reports (peer-reviewed scientific journal): "A pilot, open labelled, randomised controlled trial of hypertonic saline nasal irrigation and gargling for the common cold" (by Sandeep Ramalingam, Catriona Graham, et al.) Abstract:
The authors of that research then published a paper shortly after the outbreak of Covid, in the Journal of Global Health, titled "Hypertonic saline nasal irrigation and gargling should be considered as a treatment option for COVID-19", pointing out the relevance of their earlier study:
Furthermore, it's not actually possible to have a placebo for washing out your nose. You can have a randomized controlled double blind trial which compares washing one's nose with two different fluids, but what you cannot blind the subjects to is whether or not a fluid is going up their nose. So you cannot conduct a gold standard RCT where you compare the efficacy of a form of nasal lavage against not doing nasal lavage. Hence the RTC study above being unblinded.
What I am telling you is that there is interesting scientific evidence of benefit for a variety of simple at home or over-the-counter interventions to reduce the severity, duration, and potential for complications in Covid, but that the scientific evidence for them will never rise to the level that medications and vaccines are typically held to, for reasons that have nothing to do with their plausibility as natural phenomena, and everything to do with the nature of our society shaping which science gets done, and the very limits of what medical science it is physically possible to do.
Because of that, these interventions will probably not be promulgated by public health authorities, medical institutions, or most physicians. I am sympathetic with their reticence: I myself am reluctant to advise others to avail themselves of any of these interventions, because I do not have the kind of strong, unambiguous scientific study results I would prefer to be able to rest such a recommendation on.
I have good reason for that reticence. It is possible for an intervention to reduce the amount of virus in somebody's body, and at the same time for it to make people more vulnerable to the virus, not less. There was one notorious case, about which I might write later, in which exactly that happened. Public health authorities promoted a prophylaxis against a virus on the basis of finding that it killed the virus in the test tube. But they didn't check what it did to the bodies of the people who used it: it turned out to be so irritating, it opened up little cuts in the mucous membranes, that let the virus into the bloodstream, and made the people who used it more likely to get sick from the virus, not less.
Right now, there is a physician in the UK making the case that Covid enters the bloodstream through gum disease, and that therefore brushing, flossing, and using anti-plaque mouthwash are an important part of preventing Covid. But if he's right that Covid enters the bloodstream through the lesions on gums caused by gingivitis, well, when somebody with gingivitis brushes or flosses, it can cause their gums to bleed which – if he's right – is then a risk factor that increases their vulnerability to Covid. And I have no idea if commercial mouthwashes, many of which are quite irritating to the tissues of the mouth and throat, open up microlesions that would make one more vulnerable to Covid – exactly as in the earlier public health disaster I described.
This is why we need randomized controlled trials, to make sure that what seems likely true from logic and reasoning, turns out to actually be true in reality. Because it doesn't always.
I would love to have conclusive science on whether toothbrushing and flossing and using commercial mouthwashes is a net benefit or not, either for preventing Covid infection in the first place, or for shortening the course of the disease or mitigating its symptoms once one catches it. But I'm not holding my breath: we're not likely to get any such science. That is exactly the kind of science we are not likely to get.
We are stuck making decisions about what to do with imperfect, inadequate information. But such is the human condition. I'm not saying that experimental trials are unnecessary, I'm saying they're very necessary but we don't always get to have them, and then we have to decide what we want to do when we don't have them, and we have to decide on the basis of other weaker evidence.
Trying to practice medicine, even if only on oneself, on the basis of reasoning and not experiment is very fraught. That is true even if you are very, very smart, and very, very well educated in medicine. (Case in point, see "Paxlovid and sertraline", previously: "Reasoning about CYP interactions this way is not the worst thing in the world, scienceishly speaking, but – spoiler – this is about to become a fable as to Why You Don't Do That.")
But it is often the case that that is all we have to go on. And that is true even in medicine in general.
And the fact is, I myself, if I get Covid – or any other upper respiratory illness – I absolutely will be using some such interventions. I am reminded of something a friend of mine told me about a conversation with his PCP. He had asked his PCP about something he had heard about a supplement preventing prostate cancer, to which his PCP replied something to the effect of, "Well, the scientific evidence isn't really solid, and I would like a better RCT before recommending it to my patients, and I started taking it myself last week." I would feel bad if I didn't mention. I think you should have the choice to do so too, which is why I am explaining all this.
So I hope what I have achieved here is clarified for you how to reason, at least in part, about various recommendations and suggestions you might encounter for preventing and managing Covid. I hope to put together a list of such home treatment ideas, but it's a big research project, and a constantly moving target, so I'm not sure I'm going to pull it off, and I didn't want to make you wait any longer for it before explaining this, given how bad the present wave of Covid is. There's ideas out there about how to mitigate Covid, both getting it and its effects if you do get it, that you might want to consider, and the dose-response relationship is why.
Link for sharing: https://siderea.dreamwidth.org/1832343.html
This post brought to you by the 199 readers who funded my writing it – thank you all so much! You can see who they are at my Patreon page. If you're not one of them, and would be willing to chip in so I can write more things like this, please do so there.
Please leave comments on the Comment Catcher comment, instead of the main body of the post – unless you are commenting to get a copy of the post sent to you in email through the notification system, then go ahead and comment on it directly. Thanks!
0.
Protecting yourself from Covid requires understanding Covid correctly. One of the things that you should understand about Covid, and any infectious illness, is the dose-response relationship.
That's the fancy highfalutin' medical way of talking about a very simple idea you already have and use all the time: the bigger a dose of something you get, the stronger its effect on you.
This is usually true of medicines, of course, but it's also true of poisons. Consider lead poisoning, for example. Medical science tells us no amount of lead in the bloodstream is safe. But, as you're probably already aware, even so, having more lead in your blood is worse than having less. Somebody who has only 5 µg/dL of lead in their bloodstream is definitely lead poisoned, but they're in much better shape than somebody who has 500 µg/dL.
It turns out viruses and other infectious microbes are like poisons. Research strongly suggests viruses also have a dose-response relationship: generally speaking, the more of the virus you have inside of you, the worse your symptoms are and the greater the threat to your health.
When you think about it, that's not really a surprise, is it? It makes a lot of sense. If viruses make us sick, then people with more of a virus in them would be likely to get a lot sicker.
What sparse evidence we have about coronaviruses suggests that they may follow the pattern seen in influenza. In a 2004 study of the coronavirus that causes SARS, a cousin of the one that causes COVID-19, a team from Hong Kong found that a higher initial load of virus—measured in the nasopharynx, the cavity in the deep part of your throat above your palate—was correlated with a more severe respiratory illness. Nearly all the SARS patients who came in initially with a low or undetectable level of virus in the nasopharynx were found at a two-month follow-up to be still alive. Those with the highest level had a twenty- to forty-per-cent mortality rate. This pattern held true regardless of a patient’s age, underlying conditions, and the like. Research into another acute viral illness, Crimean-Congo hemorrhagic fever, reached a similar conclusion: the more virus you had at the start, the more likely you were to die.That's from Dr. Siddhartha Mukherjee's article "How Does the Coronavirus Behave Inside a Patient?" (2020 Mar 26, The New Yorker), which discusses the science of the dose-response relationship in viruses.
A lot of people right now are thinking of infection with Covid as a yes/no sort of thing: either you're infected or you're not. This is not true. What the reality of the dose-response relationship means is that you should be thinking of Covid (and all infections, whether viral, bacterial, fungal, or otherwise) like getting poisoned. Obviously, the best option is not to get poisoned at all. But if you do get poisoned, your next best choice is to do what you can to minimize how much poison is in you.
Now the big obvious difference between being poisoned with something like lead and contracting a viral infection is that viruses replicate. However much lead poisoning you get is how much lead poisoning you have, but if you get a small amount of Covid, left to its own devices it will rapidly turn into a large amount of Covid.
But the less obvious difference is that our bodies "know" that about infections: our bodies are built to deal with replicating attackers such as viruses. Our bodies have this whole complicated immune system for actively fighting off microbes that replicate. When some microscopic foreign invader probes our bodies' defenses or breaches them, our bodies go to war against that thing.
We do not survive encounters with such microbial attackers without our bodies mounting an effective defense against them. This is what it means to "clear" a virus. Viruses don't just give up and go away on their own. They don't just stop attacking us, and they don't just stop replicating, because they're dumb and they have no off switch. They can't. If they stop, it is because they are stopped. And the only thing to stop them is our immune systems, whether acting on their own, or with the assistance of medications.
These two facts together make the case only stronger for trying to reduce or at least attenuate the amount of Covid in you if you catch it: how much Covid you have at one point will not be the amount you have later if you let it do its thing. Left to its own devices, a little Covid becomes a lot of Covid. And the more Covid there is in you, the worse off for you and the harder it is for your body to get rid of it, the more likely your natural defenders, your immune system cells, will be overwhelmed on the field of battle.
As the Mukherjee article says, explaining why it should be that higher doses of a virus would cause more severe illness:
Rik de Swart, a virologist at Erasmus University, in Rotterdam, [said], “[...] it makes immunological sense, because the interaction between the virus and the immune system is a race in time. It’s a race between the virus finding enough target cells to replicate and the antiviral response aiming to eliminate the virus. If you give the virus a head start with a large dose, you get higher viremia [virus in the bloodstream], more dissemination, higher infection, and worse disease.”So.
Remember the expression, from back in the early parts of the pandemic, "flatten the curve"? The idea was we could – and should – protect hospitals from being overwhelmed with Covid patients by trying to keep from becoming one. Masking, socially isolating, and doing other things to protect our individual selves was something that also protected society, because the more people managed to keep themselves from contracting Covid, the slower the spread of Covid would be in the population, and the fewer Covid patients there would be who would need hospital beds. The expression "flattening the curve" captured the idea of how slowing infection is really helpful to defeating it, because it gives that which fights against it a fighting chance. It gives the cavalry a chance to arrive and save our bacon.
It turns out what was true for whole societies is just as true for our individual bodies. What was true for individual people catching Covid is true for individual cells getting invaded by SARS-CoV-2, the virus that causes COVID. If we can flatten the curve in our bodies – the growth-curve of Covid – it helps us fight off Covid. In the same way Covid spreads through a population with an exponential growth curve, Covid spreads through a body with an exponential growth curve. That's the curve we're talking about flattening, whether to give hospitals a chance to keep up with the rate of infection in a population, or to give your active immune system a chance to kick in and fight the infection off. Slowing the spread of the virus within our bodies buys our immune system time to come to our rescue.
1.
It may help to reflect on how viruses actually operate. A virus is kind of like a little chemical machine, sort of like a microscopic drone. It floats around (passively – it has no way to propel itself) on the air or in a fluid hoping (not that viruses can hope, but you get my meaning) to run into the cell of a living being. Like us. We're made of cells, which are little tiny sacks of fluid; these sacks are made of protein and the fluid has floating in it the chemical machinery to operate the cell. The virus has things on the outside of it that you can think of as kind of like infinitesimal chemical keys that correspond to little chemical locks on the outside of the cells of living things like us. The virus bumbles around hoping to bump into a cell that has a wee little matching chemical lock on the outside that its key fits. And when a viral particle finds one they can open, they invade it.
The bad news for us about Covid is that many different types of cell in the human body have a chemical lock on them called the ACE2 receptor – and Covid has the key to that lock. Covid actually has the keys to several locks that we have on the cells of our bodies, it's just that one's really common in the human body.
When the virus unlocks the cell wall, it squirts its own innards into the cell's fluid. This is the chemical machinery that runs the virus. Once inside the cell, it hijacks the cell's own chemical machinery for running the cell. So then instead of the cell manufacturing the proteins that build up the cell so it can grow or make baby cells, the inner chemical machinery of the cell taken over by the virus is put to the purpose of making copies of the virus. Eventually the the cell is so full of copies of the virus, it bursts open, scattering the virus to other nearby cells – and then the cycle repeats, only more so.
This is how viruses reproduce. They have no other way of reproducing. Like the cuckoo laying its eggs in other birds' nests, viruses don't raise their own children: they require the cells of other beings to reproduce themselves.
There's a bunch of things to notice about this process.
It's a destructive process. When the virus invades a cell, that cell's a goner. That's why infections are typically quite irritating – causing sore throats, chapped noses: the virus is rupturing the cells that make up the linings of our upper windway, shredding the tissue that is infected, with microscopic tears. This is also one of the main ways Covid kills: by damaging the linings of the fine blood vessels of the lungs, which leads to blood clots and swelling which clog them, stopping blood getting through so it can't pick up oxygen from the lung and distribute to the rest of the body.
It's an exponential process. Each time a virus particle hijacks a cell, it makes many, many times more copies of itself, so the amount of virus in the body grows very fast, and the rate of growth gets faster the more it grows, like a snowball picking up speed as it rolls downhill turning into an avalanche. A virus increases its own chance of replication each time it replicates. A cell full of virus bursting open is like a burning tree exploding in sparks, spreading a wildfire to even more trees; the bigger the wildfire gets, the faster it spreads.
This is why it is so useful to nip it in the bud. Exponential growth is ferocious, so it is both easier and more effective to stop an exponential process earlier rather than later. It is easier to quench a spark than a forest fire.
This is the fundamental premise of Paxlovid. As you probably know, Paxlovid is a medication for Covid, and the official instructions for using it are that it has to be started within 5 days of the start of symptoms. That's because the entire way Paxlovid works to help you beat Covid is that it prevents Covid virus from replicating. Its active ingredient is nirmatrelvir, a chemical which sabotages the cellular machinery in the cells that Covid invades, such that the copies of the virus that an infected cell makes no longer have the key to unlock other cells. The infected cell will still explode scattering copies of Covid – but they're defective copies, they can't infect more of your cells. (source)
Obviously, it works imperfectly, and some Covid might still manage to reproduce, and the distribution of the drug throughout your body so that all of the cells in it have it to work with is not instantaneous. But even so, at the very least pruning back the amount of Covid so radically flattens the curve – it slows the growth of Covid virus in your body, so when your body's active immune system finally kicks in, there's less Covid virus in you for it to have to try to destroy than there would be without the medication, allowed to proliferate unchecked. And ideally, pruned early, the virus hasn't had a chance to spread to more inner parts of your body that are more vulnerable to it (like the tiny arteries of the lungs) or, worse, gotten into parts of your body in which it can hide from your immune system (like your brain).
And that's why you have to take Paxlovid in the first five days of symptoms: to throttle Covid virus' growth early, the better to keep it from completely running wild in your body. Since what Paxlovid is protecting you from is sheer number of copies of the virus in your body, if you don't take it till after five days, there's not a lot Paxlovid can do for you, because by that point you're pretty much overrun with the virus. And if you have a normal immune system, by about the fifth day your immune system is as awake and involved as it's going to be, so there's no particular thing to delay for.
(That's the reasoning for the official guidelines, but given what I've explained, I bet you can see some of the cases for taking a second or later course of Paxlovid, especially in the immunocompromised. It also explains why sometimes there's rebound Covid after Paxlovid: body hasn't finished fighting it yet, and there's still some virus around, and so long as there is some around it will start to multiply.)
The other important thing to notice about the replication process of a virus such as Covid is that it's a mechanical process. The actual Covid virus particles have to actually bump into cells that they can infect, or they can't get up to any trouble. Anything that keeps viral particles from latching onto cells and hijacking them prevents them from reproducing, and slows the virus's roll, flattening the curve.
This is the obvious theory as to why we get runny noses when we get sick: that it's an evolved defense against dangerous microbes like viruses, that works by simply flushing them out of our noses with snot. Also sneezing when we get sick expels things, including snot full of viruses, out of our bodies. Coughing does the same thing for our throat and lungs.
When you think about it, a lot of the things we already know that help don't just help because they prevent catching Covid at all. They also mitigate how much Covid you get if you get Covid. For instance we wear masks in the hopes they will prevent any viral particles from coming into our mouths and noses where they can latch on and start replicating in our bodies. But even when masks don't work perfectly, and Covid particles get through anyways, the masks cut down on how many viral particles get through to us. This suggests that people who get Covid despite wearing a mask would be likely to get less sick than people who caught Covid while not wearing a mask, because they got smaller doses of Covid – and that is what the evidence currently seems to show.
This is discussed in the Journal of General Internal Medicine article "Masks Do More Than Protect Others During COVID-19: Reducing the Inoculum of SARS-CoV-2 to Protect the Wearer", by Monica Gandhi MD, MPH, et al. (2020 Jul 31) This paper was discussed in this popular press article, which notes:
In February, one of the first outbreaks of COVID-19 outside of China occurred on the Diamond Princess cruise ship docked in Yokohama, Japan. Of the 634 people on board who tested positive, about 18 percent of infections were asymptomatic. In March, an Argentinian cruise ship found itself in a similar predicament, but of the 128 people on board who eventually tested positive, 81 percent were asymptomatic.It may also explain why ventilation seems to be so helpful: by diluting contaminated air with fresh uncontaminated air, even if one doesn't completely flush all of the Covid particles out of the room, one reduces their concentration, such that not only does one have a lower likelihood of inhaling any at all, if one does inhale some it will be a much smaller dose.
A key difference, Gandhi noted, was that on the Argentinian ship, surgical masks were issued to all passengers and N95 masks to all staff as soon as the first passenger became sick.
2.
Why am I explaining all of this, since you were probably already wearing masks and ventilating your spaces and using Paxlovid as available? Because there's increasing awareness there are other things that it might be beneficial to do if one catches Covid.
For instance, there is increasing interest in using mouthwashes as a way of getting rid of Covid virus accumulating in one's mouth or throat.
The research into mouthwashes to eliminate Covid virus was initially done in the field of dentistry, with an eye to having a way to make the mouths of patients less dangerous to dental professionals working on them – that is, as a way of preventing transmission. But the dose-response relationship suggests that it could also be helpful for reducing symptoms and shortening the length of the infection.
There's also interest in the use of nasal lavage – literally washing out the insides of one's nose – as a home remedy to fight Covid.
Long before our present pandemic, there was a variety of research into the efficacy of nasal lavage and gargling, even just with simple salt water, to reduce the symptoms of severity and duration of the common cold. I understand there's not very much of it, and it's not very high-powered, but it's generally promising.
For instance, just a year before our present pandemic started, a small research study was done on whether nasal lavage and gargling reduced the length and severity of the common cold. 2019 Jan 31: Nature Scientific Reports (peer-reviewed scientific journal): "A pilot, open labelled, randomised controlled trial of hypertonic saline nasal irrigation and gargling for the common cold" (by Sandeep Ramalingam, Catriona Graham, et al.) Abstract:
[...] we conducted a pilot, non-blinded, randomised controlled trial of hypertonic saline nasal irrigation and gargling (HSNIG) vs standard care on healthy adults within 48 hours of URTI [upper respiratory tract infection] onset to assess recruitment (primary outcome). Acceptability, symptom duration and viral shedding were secondary outcomes. Participants maintained a symptom diary until well for two days or a maximum of 14 days and collected 5 sequential mid-turbinate swabs to measure viral shedding. The intervention arm prepared hypertonic saline and performed HSNIG. We recruited 68 participants (2.6 participants/week; November 2014-March 2015). A participant declined after randomisation. Another was on antibiotics and hence removed (Intervention:32, Control:34). Follow up data was available from 61 (Intervention:30, Control:31). 87% found HSNIG acceptable, 93% thought HSNIG made a difference to their symptoms. In the intervention arm, duration of illness was lower by 1.9 days (p = 0.01), over-the-counter medications (OTCM) use by 36% (p = 0.004), transmission within household contacts by 35% (p = 0.006) and viral shedding by ≥0.5 log10/day (p = 0.04). We hence need a larger trial to confirm our findings.Sterile hypertonic saline nasal rinses are available as over the counter products in this country, and are generally regarded as safe (GRAS).
The authors of that research then published a paper shortly after the outbreak of Covid, in the Journal of Global Health, titled "Hypertonic saline nasal irrigation and gargling should be considered as a treatment option for COVID-19", pointing out the relevance of their earlier study:
Post-hoc secondary analysis of data from our recent Edinburgh and Lothians Viral Intervention Study (ELVIS) pilot randomised controlled trial (RCT) indicates that hypertonic saline nasal irrigation and gargling (HSNIG) reduced the duration of coronavirus upper respiratory tract infection (URTI) by an average of two-and-a-half days. As such, it may offer a potentially safe, effective and scalable intervention in those with Coronavirus Disease-19 (COVID-19)Here's the thing. Researching whether nasal lavage or gargling with saltwater or using a viricidal mouthwash or having better ventilation in one's sick room reduces severity of symptoms, length of sickness, or overall mortality leads to neither fame nor fortune. It neither impresses any of the grant-giving institutions that fund medical science research nor advances the careers of any researcher to investigate remedies that offer the mere reduction of symptoms. Funders want to find a cure for cancer, not merely to shave two days off the common cold – and which of those is more likely to lead to a Nobel, or at least tenure? And there's no money to be made by any drug discovery company for funding research into the use of remedies that cannot be patented and which one might even be able to make at home. This is precisely the sort of research that basically never gets done at any sort of substantial scale with any sort of substantive statistical power because nobody is willing to pay for it to be done.
Furthermore, it's not actually possible to have a placebo for washing out your nose. You can have a randomized controlled double blind trial which compares washing one's nose with two different fluids, but what you cannot blind the subjects to is whether or not a fluid is going up their nose. So you cannot conduct a gold standard RCT where you compare the efficacy of a form of nasal lavage against not doing nasal lavage. Hence the RTC study above being unblinded.
What I am telling you is that there is interesting scientific evidence of benefit for a variety of simple at home or over-the-counter interventions to reduce the severity, duration, and potential for complications in Covid, but that the scientific evidence for them will never rise to the level that medications and vaccines are typically held to, for reasons that have nothing to do with their plausibility as natural phenomena, and everything to do with the nature of our society shaping which science gets done, and the very limits of what medical science it is physically possible to do.
Because of that, these interventions will probably not be promulgated by public health authorities, medical institutions, or most physicians. I am sympathetic with their reticence: I myself am reluctant to advise others to avail themselves of any of these interventions, because I do not have the kind of strong, unambiguous scientific study results I would prefer to be able to rest such a recommendation on.
I have good reason for that reticence. It is possible for an intervention to reduce the amount of virus in somebody's body, and at the same time for it to make people more vulnerable to the virus, not less. There was one notorious case, about which I might write later, in which exactly that happened. Public health authorities promoted a prophylaxis against a virus on the basis of finding that it killed the virus in the test tube. But they didn't check what it did to the bodies of the people who used it: it turned out to be so irritating, it opened up little cuts in the mucous membranes, that let the virus into the bloodstream, and made the people who used it more likely to get sick from the virus, not less.
Right now, there is a physician in the UK making the case that Covid enters the bloodstream through gum disease, and that therefore brushing, flossing, and using anti-plaque mouthwash are an important part of preventing Covid. But if he's right that Covid enters the bloodstream through the lesions on gums caused by gingivitis, well, when somebody with gingivitis brushes or flosses, it can cause their gums to bleed which – if he's right – is then a risk factor that increases their vulnerability to Covid. And I have no idea if commercial mouthwashes, many of which are quite irritating to the tissues of the mouth and throat, open up microlesions that would make one more vulnerable to Covid – exactly as in the earlier public health disaster I described.
This is why we need randomized controlled trials, to make sure that what seems likely true from logic and reasoning, turns out to actually be true in reality. Because it doesn't always.
I would love to have conclusive science on whether toothbrushing and flossing and using commercial mouthwashes is a net benefit or not, either for preventing Covid infection in the first place, or for shortening the course of the disease or mitigating its symptoms once one catches it. But I'm not holding my breath: we're not likely to get any such science. That is exactly the kind of science we are not likely to get.
We are stuck making decisions about what to do with imperfect, inadequate information. But such is the human condition. I'm not saying that experimental trials are unnecessary, I'm saying they're very necessary but we don't always get to have them, and then we have to decide what we want to do when we don't have them, and we have to decide on the basis of other weaker evidence.
Trying to practice medicine, even if only on oneself, on the basis of reasoning and not experiment is very fraught. That is true even if you are very, very smart, and very, very well educated in medicine. (Case in point, see "Paxlovid and sertraline", previously: "Reasoning about CYP interactions this way is not the worst thing in the world, scienceishly speaking, but – spoiler – this is about to become a fable as to Why You Don't Do That.")
But it is often the case that that is all we have to go on. And that is true even in medicine in general.
And the fact is, I myself, if I get Covid – or any other upper respiratory illness – I absolutely will be using some such interventions. I am reminded of something a friend of mine told me about a conversation with his PCP. He had asked his PCP about something he had heard about a supplement preventing prostate cancer, to which his PCP replied something to the effect of, "Well, the scientific evidence isn't really solid, and I would like a better RCT before recommending it to my patients, and I started taking it myself last week." I would feel bad if I didn't mention. I think you should have the choice to do so too, which is why I am explaining all this.
So I hope what I have achieved here is clarified for you how to reason, at least in part, about various recommendations and suggestions you might encounter for preventing and managing Covid. I hope to put together a list of such home treatment ideas, but it's a big research project, and a constantly moving target, so I'm not sure I'm going to pull it off, and I didn't want to make you wait any longer for it before explaining this, given how bad the present wave of Covid is. There's ideas out there about how to mitigate Covid, both getting it and its effects if you do get it, that you might want to consider, and the dose-response relationship is why.
Link for sharing: https://siderea.dreamwidth.org/1832343.html
This post brought to you by the 199 readers who funded my writing it – thank you all so much! You can see who they are at my Patreon page. If you're not one of them, and would be willing to chip in so I can write more things like this, please do so there.
Please leave comments on the Comment Catcher comment, instead of the main body of the post – unless you are commenting to get a copy of the post sent to you in email through the notification system, then go ahead and comment on it directly. Thanks!
Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-01-31 06:14 am (UTC)Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-01-31 07:58 am (UTC)I like the concept of flattening the growth curve in our bodies.
Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-01-31 11:42 pm (UTC)Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-01-31 02:12 pm (UTC)Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-01-31 06:47 pm (UTC)https://ceb.dreamwidth.org/394968.html
(Some for prevention, some for prophylaxis.)
Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-01-31 08:34 pm (UTC)It is vile. Vile vile vile.
Which surprises no one.
User experience (and possibly those micro-abrasion effects and actual virucidal levels) would be very different between salty water, OTC mouthwash, and Rx mouthwash.
Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-01-31 10:11 pm (UTC)https://blimix.dreamwidth.org/249645.html
Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-01-31 11:18 pm (UTC)Even while understanding these things as you've written, I still find them so unfortunate.
My personal anecdata so far supports the benefits of nasal irrigation. A friend also pointed out that iota-carrageenan may be worth considering.
Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-02-02 08:15 am (UTC)Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-02-02 02:32 pm (UTC)Re: Comment catcher: Covid and the Dose-Response Relationship
Date: 2024-02-01 12:35 am (UTC)(no subject)
Date: 2024-02-03 04:32 pm (UTC)