5 ms·

So what are you going to do when the virus is gone in your city/state/country, isolate yourself from the rest of the world? Because the timeline/situation will

by zambal 7y ago

So what are you going to do when the virus is gone in your city/state/country, isolate yourself from the rest of the world? Because the timeline/situation will be different for many other places.

deleted 7y ago
[deleted]
nostrademons 7y ago
Return to travel restrictions + contact tracing, and if community spread flares up again, reinstitute social distancing. Repeat until vaccine is developed.
- the-pigeon 7y ago
  It's also very normal for viruses to become more mild over time. We strongly react to strong threats. It's in the viruses interest to become a weaker threat like the common cold so we tolerate it instead of actively fighting it.
  - jeremyjh 7y ago
    They can also become much more deadly. The first pass of the 1918 pandemic was not nearly so bad as the second, which slaughtered millions of people in their 20s and 30s.
    - AnimalMuppet 7y ago
      True. But I have heard that that was because, among all the soldiers in the trenches, it could be virulent and still be able to spread effectively, so it had no selection pressure to not be virulent. Covid is a bit different, because it has a longer incubation time, but that wasn't the issue with the 1918 influenza outbreak. (Note well: I am not an epidemiologist.)
    - nostrademons 7y ago
      That's a much rarer course and seems to be related to the conditions of WW1. Under normal circumstances, people with mild illnesses are out and about and able to spread the virus, while people with severe illnesses are confined to a bed or hospital and tend to result in an evolutionary dead end. As a result, the descendants of mild cases outcompete the descendants of severe cases, and eventually natural selection results in the dominant strains of the virus all being mild. With the 1918 flu pandemic, mild cases of flu remained with their unit, while extremely sick cases were transported home via train for improved medical care. As a result, it was the severe cases that ended up sparking new infections, while the mild cases died out after generating herd immunity within an army company. Most respiratory viruses follow the first scenario, although there is a caution there for people who suggest eg. transporting sick people by airliner to regions with fewer cases to make better use of available hospital capacity. Ironically asymptomatic transmission is your best friend here: if all transmission is asymptomatic, the strains that get transmitted will be the ones more likely to not cause symptoms.
- tempestn 7y ago
  I'm not sure why you're downvoted. That is exactly the right approach. Implement serious social distancing measures to reduce R0 below 1, get local outbreak under control, and then work on keeping it contained, increasing measures when necessary. Once it's more established which countries are effectively controlling the virus, travel could be more open with those countries, and more restricted with those that still have active outbreaks. (Which doesn't necessarily mean cutting off completely, but perhaps only essential travel and cargo, or unrestricted but 14 day isolation on arrival.)
  - nostrademons 7y ago
    Interestingly, that comment started out as +3 and is down to -2 now. I think it may be a good harbinger of the public's willingness to endure repeated, long-term changes to their behavior. The way I see this going, we're going to get lockdowns in most countries within the next week or so. After 6 weeks or so, new cases will be negligible, and we'll declare victory and pick up our lives. The virus will silently spread from a few undetected cases during the summer, but then take off again around October, when we get a second wave. Assuming it hasn't mutated to become significantly less deadly (pretty likely - see sibling threads), that will be the real killer, because instead of starting from 1 index case in 1 city it'll be seeded from tens of thousands of sleeper cases across the globe. Public opinion won't support a second lockdown then - people will just be left to die with their families.
    - rapnie 7y ago
      > Interestingly, that comment started out as +3 and is down to -2 now. Is there somewhere to check that score, or is it a higher karma feature?
      - nostrademons 7y ago
        If you wrote the comment you can always see the score (0 now, FWIW). At least I've always been able to; hidden comment scores arrived a while after I'd already amassed a pretty high karma level.
    - 7y ago
coldtea 7y ago
>So what are you going to do when the virus is gone in your city/state/country, isolate yourself from the rest of the world Yes, that or have 2-4% of the infected population die...
- glogla 7y ago
  Or more, since this amount of people die only when sufficient care is available. If you interpret the "requires hospitalization" percentage as "will die without hospitalization" (which I'm not 100 % sure is true), as many as 15 or 20 % people can die.
  - learc83 7y ago
    15-20% don't require hospitalization. More were hospitalized to be monitored, but only about 40/705 infected from the Diamond Princess ever progressed to serious condition. And the population of cruise ships skews older.
voidmain 7y ago
Even if the whole world was in sync, you more or less have to hold Re below 1 forever or accept that 1-1/Re of everyone gets the virus. That's basically a tautology. But Re can be affected a lot by testing and tracing when the infected population is tiny compared to your resources, and not so much when it is huge. Re could also be affected a lot if we had a vaccine, which will probably take years in the current regulatory regime but is something that might actually benefit from disparate international approaches. It wouldn't be crazy to ask international travelers to pay the marginal cost of extra testing and/or the negative externality of spreading the virus between worse and better controlled regions.
- tempestn 7y ago
  Don't think y our 1-1/R0 rate makes sense (I assume Re is equivalent to R0 - I'm not familiar with Re). At an R0 of 1, each person spreads to one other person. So everyone would eventually be infected, just at a linear rate. Your formula though gives 1-1/1 = 0. Similarly for an R0 less than 1 your formula goes negative. Anyway, if R0 can be brought below 1, it wouldn't need to be indefinite. The further below 1 it is, the faster the virus will extinguish itself. This was seen in China, where they went from exponential growth to fewer new cases each day and ultimately to the situation now where most new cases are imported from other countries. You also don't need global coordination, although it helps. Any individual country can restrict outside travel from outbreak areas, get their own R0 below 1 via social distancing to eliminate the local outbreak, and then relax social distancing locally, relying on travel restrictions and temporary quarantines of travelers from outbreak areas, plus testing and contact tracing. If cases start to flare up again, increased social distancing measures can be brought in to get them back under control. So in theory you could do extreme distancing for a period on the order of a few months, and then normalize somewhat. It would take a global response of that sort (unlikely), a vaccine, or a change in the virus itself though to end the situation entirely.
  - voidmain 7y ago
    At an R0 of 2, with no interventions, eventually half the population has had the virus and (hopefully) gained immunity. Now each person only spreads it to 1 other person, because the other person they would have infected is immune. (If R0 was 1, the epidemic would end as soon as the next person in the chain is immune.) This is where the people saying that the virus will definitely eventually infect 70% of everyone are coming from. Re is effective spread rate, taking into account natural immunity, vaccination, contact tracing, etc. By definition, if Re>1 the epidemic is growing exponentially and if less it is shrinking.
puppymaster 7y ago
That is exactly what is happening in Malaysia and Taiwan right now. Both countries have it under control up until a couple days ago but every other country around the world is not doing well and new outbreaks are happening (returning travelers, religious gatherings). Malaysia just announced total ban of incoming and outgoing traveling for the next 2 weeks.

by zambal 7y ago

So what are you going to do when the virus is gone in your city/state/country, isolate yourself from the rest of the world? Because the timeline/situation will be different for many other places.

deleted 7y ago

[deleted]

nostrademons 7y ago

Return to travel restrictions + contact tracing, and if community spread flares up again, reinstitute social distancing. Repeat until vaccine is developed.

the-pigeon 7y ago
It's also very normal for viruses to become more mild over time. We strongly react to strong threats. It's in the viruses interest to become a weaker threat like the common cold so we tolerate it instead of actively fighting it.
- jeremyjh 7y ago
  They can also become much more deadly. The first pass of the 1918 pandemic was not nearly so bad as the second, which slaughtered millions of people in their 20s and 30s.
  - AnimalMuppet 7y ago
    True. But I have heard that that was because, among all the soldiers in the trenches, it could be virulent and still be able to spread effectively, so it had no selection pressure to not be virulent. Covid is a bit different, because it has a longer incubation time, but that wasn't the issue with the 1918 influenza outbreak. (Note well: I am not an epidemiologist.)
  - nostrademons 7y ago
    That's a much rarer course and seems to be related to the conditions of WW1. Under normal circumstances, people with mild illnesses are out and about and able to spread the virus, while people with severe illnesses are confined to a bed or hospital and tend to result in an evolutionary dead end. As a result, the descendants of mild cases outcompete the descendants of severe cases, and eventually natural selection results in the dominant strains of the virus all being mild. With the 1918 flu pandemic, mild cases of flu remained with their unit, while extremely sick cases were transported home via train for improved medical care. As a result, it was the severe cases that ended up sparking new infections, while the mild cases died out after generating herd immunity within an army company. Most respiratory viruses follow the first scenario, although there is a caution there for people who suggest eg. transporting sick people by airliner to regions with fewer cases to make better use of available hospital capacity. Ironically asymptomatic transmission is your best friend here: if all transmission is asymptomatic, the strains that get transmitted will be the ones more likely to not cause symptoms.
tempestn 7y ago
I'm not sure why you're downvoted. That is exactly the right approach. Implement serious social distancing measures to reduce R0 below 1, get local outbreak under control, and then work on keeping it contained, increasing measures when necessary. Once it's more established which countries are effectively controlling the virus, travel could be more open with those countries, and more restricted with those that still have active outbreaks. (Which doesn't necessarily mean cutting off completely, but perhaps only essential travel and cargo, or unrestricted but 14 day isolation on arrival.)
- nostrademons 7y ago
  Interestingly, that comment started out as +3 and is down to -2 now. I think it may be a good harbinger of the public's willingness to endure repeated, long-term changes to their behavior. The way I see this going, we're going to get lockdowns in most countries within the next week or so. After 6 weeks or so, new cases will be negligible, and we'll declare victory and pick up our lives. The virus will silently spread from a few undetected cases during the summer, but then take off again around October, when we get a second wave. Assuming it hasn't mutated to become significantly less deadly (pretty likely - see sibling threads), that will be the real killer, because instead of starting from 1 index case in 1 city it'll be seeded from tens of thousands of sleeper cases across the globe. Public opinion won't support a second lockdown then - people will just be left to die with their families.
  - rapnie 7y ago
    > Interestingly, that comment started out as +3 and is down to -2 now. Is there somewhere to check that score, or is it a higher karma feature?
    - nostrademons 7y ago
      If you wrote the comment you can always see the score (0 now, FWIW). At least I've always been able to; hidden comment scores arrived a while after I'd already amassed a pretty high karma level.
  - 7y ago

coldtea 7y ago

>So what are you going to do when the virus is gone in your city/state/country, isolate yourself from the rest of the world Yes, that or have 2-4% of the infected population die...

glogla 7y ago
Or more, since this amount of people die only when sufficient care is available. If you interpret the "requires hospitalization" percentage as "will die without hospitalization" (which I'm not 100 % sure is true), as many as 15 or 20 % people can die.
- learc83 7y ago
  15-20% don't require hospitalization. More were hospitalized to be monitored, but only about 40/705 infected from the Diamond Princess ever progressed to serious condition. And the population of cruise ships skews older.

voidmain 7y ago

Even if the whole world was in sync, you more or less have to hold Re below 1 forever or accept that 1-1/Re of everyone gets the virus. That's basically a tautology. But Re can be affected a lot by testing and tracing when the infected population is tiny compared to your resources, and not so much when it is huge. Re could also be affected a lot if we had a vaccine, which will probably take years in the current regulatory regime but is something that might actually benefit from disparate international approaches. It wouldn't be crazy to ask international travelers to pay the marginal cost of extra testing and/or the negative externality of spreading the virus between worse and better controlled regions.

tempestn 7y ago
Don't think y our 1-1/R0 rate makes sense (I assume Re is equivalent to R0 - I'm not familiar with Re). At an R0 of 1, each person spreads to one other person. So everyone would eventually be infected, just at a linear rate. Your formula though gives 1-1/1 = 0. Similarly for an R0 less than 1 your formula goes negative. Anyway, if R0 can be brought below 1, it wouldn't need to be indefinite. The further below 1 it is, the faster the virus will extinguish itself. This was seen in China, where they went from exponential growth to fewer new cases each day and ultimately to the situation now where most new cases are imported from other countries. You also don't need global coordination, although it helps. Any individual country can restrict outside travel from outbreak areas, get their own R0 below 1 via social distancing to eliminate the local outbreak, and then relax social distancing locally, relying on travel restrictions and temporary quarantines of travelers from outbreak areas, plus testing and contact tracing. If cases start to flare up again, increased social distancing measures can be brought in to get them back under control. So in theory you could do extreme distancing for a period on the order of a few months, and then normalize somewhat. It would take a global response of that sort (unlikely), a vaccine, or a change in the virus itself though to end the situation entirely.
- voidmain 7y ago
  At an R0 of 2, with no interventions, eventually half the population has had the virus and (hopefully) gained immunity. Now each person only spreads it to 1 other person, because the other person they would have infected is immune. (If R0 was 1, the epidemic would end as soon as the next person in the chain is immune.) This is where the people saying that the virus will definitely eventually infect 70% of everyone are coming from. Re is effective spread rate, taking into account natural immunity, vaccination, contact tracing, etc. By definition, if Re>1 the epidemic is growing exponentially and if less it is shrinking.

puppymaster 7y ago

That is exactly what is happening in Malaysia and Taiwan right now. Both countries have it under control up until a couple days ago but every other country around the world is not doing well and new outbreaks are happening (returning travelers, religious gatherings). Malaysia just announced total ban of incoming and outgoing traveling for the next 2 weeks.