4 ms·

> Should you get it again, say 3 to 5 months from now when whatever immune response you have going on right now fades away, your symptoms run a good chance of b

> Should you get it again, say 3 to 5 months from now when whatever immune response you have going on right now fades away, your symptoms run a good chance of being much, much worse. Why would it be worse if one gets it again?

tripletao 6y ago
First, there's no reason to expect that your immune response will fade in 3-5 months. The concentration of antibodies in the blood does decrease with time, but immunity to the original SARS lasted at least for years[1]. For a virus that was only discovered X months ago, it's impossible to demonstrate that immunity lasts longer than X months; but it seems pretty likely to me. Second, there's no firm evidence that anyone has ever been reinfected yet[2], but there's no specific reason to believe that your symptoms would be worse the second time. Antibody-dependent enhancement was observed with some vaccine candidates for the original SARS[3], but so far the SARS-CoV-2 vaccine candidates haven't shown that. In the other direction, I've seen speculation that some modern common colds are the faint echoes of ancient pandemics, and SARS-CoV-2 would eventually end up similar if uncontrolled, with immunity acquired initially in childhood (where the IFR is not zero but extremely small, 16 per million[4]) and reinforced with mild infections throughout one's life. 1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/ 2. The evidence for reinfection is that some people have tested positive then negative then positive by PCR, and perhaps their symptoms got worse then better then worse again too; but since the PCR test has a significant false negative rate, it might just be one long illness. 3. https://www.nature.com/articles/s41587-020-0577-1 https://www.nature.com/articles/s41587-020-0577-1 4. https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30243-7/fulltext https://www.thelancet.com/journals/laninf/article/PIIS1473-3...
- ddingus 6y ago
  There is no reason to assume it will endure either. What we need to do is be conservative and gather data and work to understand better. Right now, our understanding is limited. We do not yet have a full cycle behind us. That's one year minimum. Until we have a more solid basis, the risks are minimized for everyone by operating in a risk adverse way. We are in a global scenario, rapidly moving to endemic mode. Far too many are not reasonable and prudent and we all will pay for that.
- ddingus 6y ago
  Let me put it this way: We want things to be true and universal. People vary widely in their response to this virus. We do not understand why very well. A lot remains unclear. Too much. This mode we are in could be the default for a sustained time. As we go through the year, I see that as being increasingly likely. As people face reality as it is being shown to us, I expect large numbers of them to get on with living differently as we work on cures and hopefully vaccine. Until we actualize those things, caution is totally warranted and indicated. Most of the world gets that. The US doesn't yet. There are reasons why our passports aren't much good right now. Our discussion here is one of them. All you put here is suggestive and hopeful. Let's hope. In the meantime, we don't know as much as we should and caution is again, totally warranted and indicated.
  - tripletao 6y ago
    Please don't take anything I wrote above as an argument to abandon caution and let the pandemic burn uncontrolled--as you'll see from my posts elsewhere on this page, I'm strongly in favor of mask use, social distancing, and other simple and relatively inexpensive interventions. I don't want to see people acting recklessly, but neither do I want to seem them in despair from an outlook more pessimistic than the best current science would support.
    - ddingus 6y ago
      Fair enough. There is a lot of want it to just go away out there. Worries me more than pessimism does. (That is at least warranted, even if not optimal) I, frankly, don't care about expense so much either. People are high value. Cannot be replaced. Economic implications are not good. Nothing to look forward to at present. For me personally, I am just going to scale down. Done right, it does not have to mean less, just differently.
      - tripletao 6y ago
        I mean "inexpensive" both in dollars and in overall social cost. Closing the schools might actually save money short-term, but society will be paying for those children's interrupted education for a long time. In any case, I agree that the virus will be with us for many months to come. I'm optimistic that with strict mask use and loose other interventions (anything involving large crowds closed, but most other facilities open, mostly prudent individual behavior) we can control the virus, as Japan seems to have. The political progress towards that has been pretty rough, but maybe it's beginning to converge.
ddingus 6y ago
The top reason would be our body and or immune system was impacted the first time. Assumptions about CoV19 are unwise right now in my book. The data is coming in real time. We know a lot less than many would prefer, or believe.

tripletao 6y ago

First, there's no reason to expect that your immune response will fade in 3-5 months. The concentration of antibodies in the blood does decrease with time, but immunity to the original SARS lasted at least for years[1]. For a virus that was only discovered X months ago, it's impossible to demonstrate that immunity lasts longer than X months; but it seems pretty likely to me. Second, there's no firm evidence that anyone has ever been reinfected yet[2], but there's no specific reason to believe that your symptoms would be worse the second time. Antibody-dependent enhancement was observed with some vaccine candidates for the original SARS[3], but so far the SARS-CoV-2 vaccine candidates haven't shown that. In the other direction, I've seen speculation that some modern common colds are the faint echoes of ancient pandemics, and SARS-CoV-2 would eventually end up similar if uncontrolled, with immunity acquired initially in childhood (where the IFR is not zero but extremely small, 16 per million[4]) and reinforced with mild infections throughout one's life. 1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851497/ 2. The evidence for reinfection is that some people have tested positive then negative then positive by PCR, and perhaps their symptoms got worse then better then worse again too; but since the PCR test has a significant false negative rate, it might just be one long illness. 3. https://www.nature.com/articles/s41587-020-0577-1 https://www.nature.com/articles/s41587-020-0577-1 4. https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30243-7/fulltext https://www.thelancet.com/journals/laninf/article/PIIS1473-3...

ddingus 6y ago
There is no reason to assume it will endure either. What we need to do is be conservative and gather data and work to understand better. Right now, our understanding is limited. We do not yet have a full cycle behind us. That's one year minimum. Until we have a more solid basis, the risks are minimized for everyone by operating in a risk adverse way. We are in a global scenario, rapidly moving to endemic mode. Far too many are not reasonable and prudent and we all will pay for that.
ddingus 6y ago
Let me put it this way: We want things to be true and universal. People vary widely in their response to this virus. We do not understand why very well. A lot remains unclear. Too much. This mode we are in could be the default for a sustained time. As we go through the year, I see that as being increasingly likely. As people face reality as it is being shown to us, I expect large numbers of them to get on with living differently as we work on cures and hopefully vaccine. Until we actualize those things, caution is totally warranted and indicated. Most of the world gets that. The US doesn't yet. There are reasons why our passports aren't much good right now. Our discussion here is one of them. All you put here is suggestive and hopeful. Let's hope. In the meantime, we don't know as much as we should and caution is again, totally warranted and indicated.
- tripletao 6y ago
  Please don't take anything I wrote above as an argument to abandon caution and let the pandemic burn uncontrolled--as you'll see from my posts elsewhere on this page, I'm strongly in favor of mask use, social distancing, and other simple and relatively inexpensive interventions. I don't want to see people acting recklessly, but neither do I want to seem them in despair from an outlook more pessimistic than the best current science would support.
  - ddingus 6y ago
    Fair enough. There is a lot of want it to just go away out there. Worries me more than pessimism does. (That is at least warranted, even if not optimal) I, frankly, don't care about expense so much either. People are high value. Cannot be replaced. Economic implications are not good. Nothing to look forward to at present. For me personally, I am just going to scale down. Done right, it does not have to mean less, just differently.
    - tripletao 6y ago
      I mean "inexpensive" both in dollars and in overall social cost. Closing the schools might actually save money short-term, but society will be paying for those children's interrupted education for a long time. In any case, I agree that the virus will be with us for many months to come. I'm optimistic that with strict mask use and loose other interventions (anything involving large crowds closed, but most other facilities open, mostly prudent individual behavior) we can control the virus, as Japan seems to have. The political progress towards that has been pretty rough, but maybe it's beginning to converge.

ddingus 6y ago

The top reason would be our body and or immune system was impacted the first time. Assumptions about CoV19 are unwise right now in my book. The data is coming in real time. We know a lot less than many would prefer, or believe.