9 ms·

Corona Simulator

271 points by mef 7y ago

yummypaint 7y ago
This is a great intuitive set of models. It also suggests scenarios where a poorly implemented quarantine could make things worse by intensifying contact and increasing spread between those isolated together, and then releasing everyone while still contagious. It drives home that if people are forcibly kept in close quarters for quarantine, its essential to see the full time period through. If resources might eventually wear thin enough that a quarantine may not be sustainable, it's probably better not to do it at all.
- jariel 7y ago
  I think it illustrates what happened on the 'cruise ship' (i.e. close proximity, clustered) quarantines, but it doesn't very well explain what real, individual quarantine would do.
  - iso1631 7y ago
    What was interesting on the cruise ships is how few got it. Of the 3,681 tested, only 696 had it - after a month of close quarters. That's under 20%. Doesn't that suggest it doesn't spread particularly easily? All in all, 1% of those that caught it died, and cruise ships skew towards older people.
- mensetmanusman 7y ago
  This is what happened in China. People in Wuhan heard the quarantine was coming and hundreds of thousand fled. Then, everyone was forced to stay together without access to medical supplies due to the quarantine. That is why the fatality rate was so much higher in Wuhan. If China hadn’t arrested the whistle blowers, the situation would be a lot different.
raynguyen 7y ago
The thing is, with these models. Everyone will eventually catch the virus and either dies off or recovers. If this happens in real life, the consequences are dire and catastrophic. Social distancing and avoiding large groups will obviously save lives and we flatten the curve to allow for treatment of individuals that will require hospitalization. But once the novelty of social distancing wears off. Will the number of cases where people get affected explode once again? The question is when will this virus go away? (if ever). Will everybody catch it eventually? Will the panic fade and Corona be just another (and much deadlier) strain of the flu?
- ysleepy 7y ago
  It is still hard to grasp that the entire human civilization will be infected with this not yet fully understood virus. What if it makes everyone infertile? Real Children of Men scenario. The measures taken are optimistic, but when everything is one the line, you have to make pessimistic decisions. First avoid human extinction. Making bets with human kind as the wager are immoral in the highest order.
  - shintakezou 7y ago
    What if it gives the survivors the strength to resist or fight back something else? If we think about it, human (and not human) very ancient history must be full of these interactions, and our evolution is a consequence also of this kind of thing. Only recently we know how to "protect" ourselves. But if we are in the what-if domain... what if letting it go make us a biologically better being? What if it by chance will give us the protection against some kind of tumor? What if its overall effect, not counting the deaths, is positive and not negative like making us infertile? What if.... We can't know. But we'll see one side of the coin when we'll have defeated this threat. (Which is not an existential threat, anyway, i.e. it won't make us go extinct)
- cl42 7y ago
  That’s actually not correct, and the point of the simulations is to show that. By social distancing, you reduce the likelihood of everyone getting the disease. The use of social distancing brings the probability that everyone gets infected at some point closer to 0.0 but doesn’t make it 0.0. It’s possible to have a result where you either have people who were never infected, or ones who are fully recovered. That’s what they’re driving at.
pvinis 7y ago
Can I just comment on the (IMO bad) choice of colors? It's hard to see the difference of sick and recovered, especially in the big square. Other than that, nice simulations. :)
- maigret 7y ago
  Indeed, the contrast is low and probably not very accessible. Their design system should consider that so it’s not up to some designer or developer to decide case by case during crunch time.
- inportb 7y ago
  Especially for the color-blind; specifically, those with tritanopia would find it difficult to distinguish the violet recovered balls from the brown sick balls.
lucb1e 7y ago
Can't view due to cookiewall, is this an article about a simulator somewhere (that someone could link) or is the simulator their own?
- asdf21 7y ago
  It has built in javascript simulators.
- catacombs 7y ago
  Why don’t you support the paper and buy a subscription?
  - lucb1e 7y ago
    Because it isn't nearly worth $90 to me, I barely ever read any of their articles. It's also not something I can look at before deciding whether I want to pay for it, not like a product in a shop or something I can order and return (unused) for 14 days. If paying 50 cents for this article was possible, I would have no idea what I'm getting (beyond the title "Corona Simulator") or whether it's worth it, though a one-time 50 cents charge would definitely be more considerable than a recurring and more expensive subscription.
    - catacombs 7y ago
      Where do you get your news?
      - lucb1e 7y ago
        General news? Most things that actually impact my life, people (colleagues, friends, family) will tell me about it; the rest mostly passes me by. Some comes from HN, and when there is a big story I'll sometimes browse to nos.nl, but that's about it. Tech news I keep up with at Tweakers.net, where I have a subscription. Well, and HN again of course, but a lot of that is personal blogs, show/ask HN posts, and a minority of what I click is research/tech news which then breaks down further into many different outlets. I also use Reddit but the closest sub I have to news is r/globaltalk, so that's mostly people talking about what's going on near them and not journalists that need to be paid.
magoghm 7y ago
Nice simulations. But I believe that using a population of only 200 individuals might be giving misleading results because it enters too fast the logistic limit part of the curve before you can experience the early exponential part. https://www.dummies.com/education/science/environmental-science/the-environmental-science-of-population-growth-models/ https://www.dummies.com/education/science/environmental-scie...
- jgwil2 7y ago
  Yep. Would be nice if they let the user play around with the parameters. Might not be feasible to animate thousands of objects in a browser though.
  - catacombs 7y ago
    Exactly. The most, at best, could be 1,000, but will that be enough? This project was likely built on a tight deadline and getting it out quickly onto multiple devices was the goal. If someone has a better approach, I’d love to hear it.
azinman2 7y ago
What I don’t get is that we keep hearing quarantine isn’t effective, yet it seems to be in China and South Korea: https://www.businessinsider.com/coronavirus-lockdowns-work-statistics-by-country-2020-3?amp https://www.businessinsider.com/coronavirus-lockdowns-work-s...
- darkerside 7y ago
  I think it's more of, quarantine isn't economically feasible. But then, things that aren't feasible can often become feasible in different circumstances.
  - mantap 7y ago
    Economically it doesn't make much difference. You can either isolate people now or later. The period of isolation will be roughly the same because you have to wait for the virus to exhaust its pool of hosts (in a household). Definitely politically it makes a big difference.
    - darkerside 7y ago
      Now and later make a HUGE difference economically. Time value of money. Business cash flow. Not to mention, if it turns out to be unnecessary later, later becomes never.
      - azinman2 7y ago
        The scale of the problem will be so much larger because we aren’t doing a quarantine. In an exponentially growing virus, one single day makes a large difference.
      - jopsen 7y ago
        True, there might also be a vaccine in the future. Another argument is that we just need it to grow slow enough for a vaccine to be ready.
- rst 7y ago
nyolfen 7y ago
> “As Lawrence O. Gostin, a professor of global health law at Georgetown University, put it: “The truth is those kinds of lockdowns are very rare and never effective.”” uh, except... the one we all just watched be successfully implemented in wuhan?
- tantalor 7y ago
  In a police state
- hn_throwaway_99 7y ago
  Except what was really implemented in Wuhan was really not just quarantine, but was also an extreme form of social distancing, where essentially the whole province of Wuhan was locked down.
  - deleted 7y ago
    [deleted]
  - hawkice 7y ago
    *Hubei
- glaive123 7y ago
  except it may not be successful yet you are just taking for granted the data provided to you by an authoritarian state
  - gamegod 7y ago
    You don't need to rely on the data by the Chinese government, for several reasons: 1) Lots of epidemiological papers about the Wuhan epidemic use data from phone carriers (not the government) to track the spread and make predictions, and they were generally pretty good with their forecasts. The numbers reported by the government are consistent with the forecasts from scientists. 2) The numbers reported by China are also consistent with the spread observed _outside_ of China. You can't lie about the numbers because every other country would detect an anomalous number of imported cases. (Case point - In Canada, we're importing way more cases from the US than you'd expect if there were actually only 1200 cases in the US. This is rather because the US is lagging so far behind in testing, rather than outright deception.) The absolute numbers don't even matter that much - what matters is the trend and the number of new cases going to zero. Look at epidemiology paper - they always assume only like 10% of infected cases are tested and confirmed. The epidemic really is coming to a close in China, still gaining momentum in Europe, and coming in a big way soon to North America.
joppy 7y ago
My understanding of a lot of countries approaches is that they're not trying to minimise the total number of people that have or will be infected, but they're trying to minimise the maximum number of people infected at a time (to ensure that healthcare is still available to everybody that needs it). In these simulations, that would correspond to drawing some horizontal line across the chart and trying to keep the orange under there the whole time. I'm not sure if the long-term outlook is "we're all going to get it" like the flu, or we're trying to stave as much of it off before a vaccine is widely available.
- jacquesm 7y ago
  A vaccine may never be available. There are plenty of viruses for which we have been unable to develop an effective vaccine that doesn't kill more people than it saves.
- shintakezou 7y ago
  > trying to minimise the maximum number of people infected at a time (to ensure that healthcare is still available to everybody that needs it). It is so, at least in Italy. Basically they told us the reason of these measure is to spread the cases over a larger time frame... but nobody has said it's to reduce the number of cases.
glaive123 7y ago
The people who don't understand this stuff, aren't failing to understand it because no one wrote about it. It's because they are not white collar or college graduates and are not likely to read The Washington Post in the first place. My father is the perfect example of this. He's dyslexic and so he struggles to read detailed journalism and gets all of his information from cable TV news like Fox News.
- maxerickson 7y ago
  There's really not a 1:1 relationship between "college" and "white collar", and "curiosity". Plenty of people with their fancy college degree are incurious, and plenty of people that barely made it out of high school are curious. It's an appealing shorthand, but it's not a great one.
  - glaive123 7y ago
    Obviously there's not a 1:1 relationship. And I never made such claim. I am saying that the people who read detailed journalism tend to have a higher reading level, e.g. they work in a job where reading and analysis is a daily part of their work, this would be considered white collar. Please don't put words in my mouth when I never said there was a 1:1 relationship.
- catacombs 7y ago
  What’s sad is cable news visual teams do not have the resources to do these kinds of awesome visualizations.
robotresearcher 7y ago
One thing about this sim bothers me. Having points bounce off each other means they migrate more slowly and increases the effective contact graph diameter. Bouncing points aren't meaningful for the system being modeled. Me staying at home doesn't restrict your movements: our decisions are independent. IMHO he should turn off the collision model. The effect will still be there, but the logistic parameters will be different.
- IgorPartola 7y ago
  Yeah this is good for cells in a blood stream, not humans. Also humans interact with other humans unevenly: you see your family and coworkers more often and for more time than a random barista. Except the barista where you always get your coffee on your lunch break. And then you have social mavens who interact with loads of people. If you work in an office with 15 other people, your social circle is likely on the order of like 100-200 people. If you do public speaking for a living, your social circle is in the thousands. Would be better to simulate it that way.
Rapzid 7y ago
There seems to be a very well defined separation between those who have a relatively high chance of becoming critically ill, and those who have a very low chance. Depending on what you are optimizing for it could be more important to keep those groups separated. I wonder if having known that for weeks now has lead to better social distancing between those groups, even if interactions within the low risk group has stayed rather high. Could lead to a lot of spread with very little detection because we largely only test for and catch the really bad cases.
Leary 7y ago
I think this pandemic will reveal many facets on the effectiveness of quarantines/lock downs. These measures always have a political meaning, because they effectively create a separation between those included and those excluded from the quarantine. Such a political move will pressure some politicians toward implementing these lockdowns if they are targeted toward foreigners and away from them if implemented toward a domestic subgroup. It may be easy to ban travel from Europe, but very hard to ban travel from Washington state.
hackandtrip 7y ago
The comparison between social distancing and quarantine has 0 sense. In Italy, we tried distancing, but without strict measures, people won't listen and the virus kept spreading. You can't enforce something like that without police action
- rdtwo 7y ago
  We’re there in Seattle right now exact same failure mode
- jopsen 7y ago
  Yeah, I think you need large numbers of tests, because unless you test people positive they are not likely to respect self isolation.
rdtwo 7y ago
The problem we’re seeing is that too many people are moving. Seattle was maybe 25% slower Sunday than normal. That’s not enough, people aren’t respecting social distancing or even the 250 gathering limits. Seattle pd is failing to enforce as well.
yogafiremf 7y ago
>"Recovered person can neither transmit simulitis to a healthy person nor become sick again after coming in contact with a sick person." The assumption is wrong. There are several cases of recovered patients getting coronavirus again. This virus is similar to HIV. https://www.channelnewsasia.com/news/asia/japan-woman-covid-19-coronavirus-second-time-recovered-12474880 https://www.channelnewsasia.com/news/asia/japan-woman-covid-...
- jopsen 7y ago
  Can you find a more credible source. There will always be individual examples. But what is the norm.
- jonshariat 7y ago
  From the reports I've seen, they have tested positive again which is different than getting it again.

271 points by mef 7y ago

This is a great intuitive set of models. It also suggests scenarios where a poorly implemented quarantine could make things worse by intensifying contact and increasing spread between those isolated together, and then releasing everyone while still contagious. It drives home that if people are forcibly kept in close quarters for quarantine, its essential to see the full time period through. If resources might eventually wear thin enough that a quarantine may not be sustainable, it's probably better not to do it at all.

jariel 7y ago
I think it illustrates what happened on the 'cruise ship' (i.e. close proximity, clustered) quarantines, but it doesn't very well explain what real, individual quarantine would do.
- iso1631 7y ago
  What was interesting on the cruise ships is how few got it. Of the 3,681 tested, only 696 had it - after a month of close quarters. That's under 20%. Doesn't that suggest it doesn't spread particularly easily? All in all, 1% of those that caught it died, and cruise ships skew towards older people.
mensetmanusman 7y ago
This is what happened in China. People in Wuhan heard the quarantine was coming and hundreds of thousand fled. Then, everyone was forced to stay together without access to medical supplies due to the quarantine. That is why the fatality rate was so much higher in Wuhan. If China hadn’t arrested the whistle blowers, the situation would be a lot different.

raynguyen 7y ago

The thing is, with these models. Everyone will eventually catch the virus and either dies off or recovers. If this happens in real life, the consequences are dire and catastrophic. Social distancing and avoiding large groups will obviously save lives and we flatten the curve to allow for treatment of individuals that will require hospitalization. But once the novelty of social distancing wears off. Will the number of cases where people get affected explode once again? The question is when will this virus go away? (if ever). Will everybody catch it eventually? Will the panic fade and Corona be just another (and much deadlier) strain of the flu?

ysleepy 7y ago
It is still hard to grasp that the entire human civilization will be infected with this not yet fully understood virus. What if it makes everyone infertile? Real Children of Men scenario. The measures taken are optimistic, but when everything is one the line, you have to make pessimistic decisions. First avoid human extinction. Making bets with human kind as the wager are immoral in the highest order.
- shintakezou 7y ago
  What if it gives the survivors the strength to resist or fight back something else? If we think about it, human (and not human) very ancient history must be full of these interactions, and our evolution is a consequence also of this kind of thing. Only recently we know how to "protect" ourselves. But if we are in the what-if domain... what if letting it go make us a biologically better being? What if it by chance will give us the protection against some kind of tumor? What if its overall effect, not counting the deaths, is positive and not negative like making us infertile? What if.... We can't know. But we'll see one side of the coin when we'll have defeated this threat. (Which is not an existential threat, anyway, i.e. it won't make us go extinct)
cl42 7y ago
That’s actually not correct, and the point of the simulations is to show that. By social distancing, you reduce the likelihood of everyone getting the disease. The use of social distancing brings the probability that everyone gets infected at some point closer to 0.0 but doesn’t make it 0.0. It’s possible to have a result where you either have people who were never infected, or ones who are fully recovered. That’s what they’re driving at.

pvinis 7y ago

Can I just comment on the (IMO bad) choice of colors? It's hard to see the difference of sick and recovered, especially in the big square. Other than that, nice simulations. :)

maigret 7y ago
Indeed, the contrast is low and probably not very accessible. Their design system should consider that so it’s not up to some designer or developer to decide case by case during crunch time.
inportb 7y ago
Especially for the color-blind; specifically, those with tritanopia would find it difficult to distinguish the violet recovered balls from the brown sick balls.

lucb1e 7y ago

Can't view due to cookiewall, is this an article about a simulator somewhere (that someone could link) or is the simulator their own?

asdf21 7y ago
It has built in javascript simulators.
catacombs 7y ago
Why don’t you support the paper and buy a subscription?
- lucb1e 7y ago
  Because it isn't nearly worth $90 to me, I barely ever read any of their articles. It's also not something I can look at before deciding whether I want to pay for it, not like a product in a shop or something I can order and return (unused) for 14 days. If paying 50 cents for this article was possible, I would have no idea what I'm getting (beyond the title "Corona Simulator") or whether it's worth it, though a one-time 50 cents charge would definitely be more considerable than a recurring and more expensive subscription.
  - catacombs 7y ago
    Where do you get your news?
    - lucb1e 7y ago
      General news? Most things that actually impact my life, people (colleagues, friends, family) will tell me about it; the rest mostly passes me by. Some comes from HN, and when there is a big story I'll sometimes browse to nos.nl, but that's about it. Tech news I keep up with at Tweakers.net, where I have a subscription. Well, and HN again of course, but a lot of that is personal blogs, show/ask HN posts, and a minority of what I click is research/tech news which then breaks down further into many different outlets. I also use Reddit but the closest sub I have to news is r/globaltalk, so that's mostly people talking about what's going on near them and not journalists that need to be paid.

magoghm 7y ago

Nice simulations. But I believe that using a population of only 200 individuals might be giving misleading results because it enters too fast the logistic limit part of the curve before you can experience the early exponential part. https://www.dummies.com/education/science/environmental-science/the-environmental-science-of-population-growth-models/ https://www.dummies.com/education/science/environmental-scie...

jgwil2 7y ago
Yep. Would be nice if they let the user play around with the parameters. Might not be feasible to animate thousands of objects in a browser though.
- catacombs 7y ago
  Exactly. The most, at best, could be 1,000, but will that be enough? This project was likely built on a tight deadline and getting it out quickly onto multiple devices was the goal. If someone has a better approach, I’d love to hear it.

azinman2 7y ago

What I don’t get is that we keep hearing quarantine isn’t effective, yet it seems to be in China and South Korea: https://www.businessinsider.com/coronavirus-lockdowns-work-statistics-by-country-2020-3?amp https://www.businessinsider.com/coronavirus-lockdowns-work-s...

darkerside 7y ago
I think it's more of, quarantine isn't economically feasible. But then, things that aren't feasible can often become feasible in different circumstances.
- mantap 7y ago
  Economically it doesn't make much difference. You can either isolate people now or later. The period of isolation will be roughly the same because you have to wait for the virus to exhaust its pool of hosts (in a household). Definitely politically it makes a big difference.
  - darkerside 7y ago
    Now and later make a HUGE difference economically. Time value of money. Business cash flow. Not to mention, if it turns out to be unnecessary later, later becomes never.
    - azinman2 7y ago
      The scale of the problem will be so much larger because we aren’t doing a quarantine. In an exponentially growing virus, one single day makes a large difference.
    - jopsen 7y ago
      True, there might also be a vaccine in the future. Another argument is that we just need it to grow slow enough for a vaccine to be ready.
rst 7y ago

nyolfen 7y ago

> “As Lawrence O. Gostin, a professor of global health law at Georgetown University, put it: “The truth is those kinds of lockdowns are very rare and never effective.”” uh, except... the one we all just watched be successfully implemented in wuhan?

tantalor 7y ago
In a police state
hn_throwaway_99 7y ago
Except what was really implemented in Wuhan was really not just quarantine, but was also an extreme form of social distancing, where essentially the whole province of Wuhan was locked down.
- deleted 7y ago
  [deleted]
- hawkice 7y ago
  *Hubei
glaive123 7y ago
except it may not be successful yet you are just taking for granted the data provided to you by an authoritarian state
- gamegod 7y ago
  You don't need to rely on the data by the Chinese government, for several reasons: 1) Lots of epidemiological papers about the Wuhan epidemic use data from phone carriers (not the government) to track the spread and make predictions, and they were generally pretty good with their forecasts. The numbers reported by the government are consistent with the forecasts from scientists. 2) The numbers reported by China are also consistent with the spread observed _outside_ of China. You can't lie about the numbers because every other country would detect an anomalous number of imported cases. (Case point - In Canada, we're importing way more cases from the US than you'd expect if there were actually only 1200 cases in the US. This is rather because the US is lagging so far behind in testing, rather than outright deception.) The absolute numbers don't even matter that much - what matters is the trend and the number of new cases going to zero. Look at epidemiology paper - they always assume only like 10% of infected cases are tested and confirmed. The epidemic really is coming to a close in China, still gaining momentum in Europe, and coming in a big way soon to North America.

joppy 7y ago

My understanding of a lot of countries approaches is that they're not trying to minimise the total number of people that have or will be infected, but they're trying to minimise the maximum number of people infected at a time (to ensure that healthcare is still available to everybody that needs it). In these simulations, that would correspond to drawing some horizontal line across the chart and trying to keep the orange under there the whole time. I'm not sure if the long-term outlook is "we're all going to get it" like the flu, or we're trying to stave as much of it off before a vaccine is widely available.

jacquesm 7y ago
A vaccine may never be available. There are plenty of viruses for which we have been unable to develop an effective vaccine that doesn't kill more people than it saves.
shintakezou 7y ago
> trying to minimise the maximum number of people infected at a time (to ensure that healthcare is still available to everybody that needs it). It is so, at least in Italy. Basically they told us the reason of these measure is to spread the cases over a larger time frame... but nobody has said it's to reduce the number of cases.

glaive123 7y ago

The people who don't understand this stuff, aren't failing to understand it because no one wrote about it. It's because they are not white collar or college graduates and are not likely to read The Washington Post in the first place. My father is the perfect example of this. He's dyslexic and so he struggles to read detailed journalism and gets all of his information from cable TV news like Fox News.

maxerickson 7y ago
There's really not a 1:1 relationship between "college" and "white collar", and "curiosity". Plenty of people with their fancy college degree are incurious, and plenty of people that barely made it out of high school are curious. It's an appealing shorthand, but it's not a great one.
- glaive123 7y ago
  Obviously there's not a 1:1 relationship. And I never made such claim. I am saying that the people who read detailed journalism tend to have a higher reading level, e.g. they work in a job where reading and analysis is a daily part of their work, this would be considered white collar. Please don't put words in my mouth when I never said there was a 1:1 relationship.
catacombs 7y ago
What’s sad is cable news visual teams do not have the resources to do these kinds of awesome visualizations.

robotresearcher 7y ago

One thing about this sim bothers me. Having points bounce off each other means they migrate more slowly and increases the effective contact graph diameter. Bouncing points aren't meaningful for the system being modeled. Me staying at home doesn't restrict your movements: our decisions are independent. IMHO he should turn off the collision model. The effect will still be there, but the logistic parameters will be different.

IgorPartola 7y ago
Yeah this is good for cells in a blood stream, not humans. Also humans interact with other humans unevenly: you see your family and coworkers more often and for more time than a random barista. Except the barista where you always get your coffee on your lunch break. And then you have social mavens who interact with loads of people. If you work in an office with 15 other people, your social circle is likely on the order of like 100-200 people. If you do public speaking for a living, your social circle is in the thousands. Would be better to simulate it that way.

Rapzid 7y ago

There seems to be a very well defined separation between those who have a relatively high chance of becoming critically ill, and those who have a very low chance. Depending on what you are optimizing for it could be more important to keep those groups separated. I wonder if having known that for weeks now has lead to better social distancing between those groups, even if interactions within the low risk group has stayed rather high. Could lead to a lot of spread with very little detection because we largely only test for and catch the really bad cases.

Leary 7y ago

I think this pandemic will reveal many facets on the effectiveness of quarantines/lock downs. These measures always have a political meaning, because they effectively create a separation between those included and those excluded from the quarantine. Such a political move will pressure some politicians toward implementing these lockdowns if they are targeted toward foreigners and away from them if implemented toward a domestic subgroup. It may be easy to ban travel from Europe, but very hard to ban travel from Washington state.

hackandtrip 7y ago

The comparison between social distancing and quarantine has 0 sense. In Italy, we tried distancing, but without strict measures, people won't listen and the virus kept spreading. You can't enforce something like that without police action

rdtwo 7y ago
We’re there in Seattle right now exact same failure mode
jopsen 7y ago
Yeah, I think you need large numbers of tests, because unless you test people positive they are not likely to respect self isolation.

rdtwo 7y ago

The problem we’re seeing is that too many people are moving. Seattle was maybe 25% slower Sunday than normal. That’s not enough, people aren’t respecting social distancing or even the 250 gathering limits. Seattle pd is failing to enforce as well.

yogafiremf 7y ago

>"Recovered person can neither transmit simulitis to a healthy person nor become sick again after coming in contact with a sick person." The assumption is wrong. There are several cases of recovered patients getting coronavirus again. This virus is similar to HIV. https://www.channelnewsasia.com/news/asia/japan-woman-covid-19-coronavirus-second-time-recovered-12474880 https://www.channelnewsasia.com/news/asia/japan-woman-covid-...

jopsen 7y ago
Can you find a more credible source. There will always be individual examples. But what is the norm.
jonshariat 7y ago
From the reports I've seen, they have tested positive again which is different than getting it again.