PlagueWatch 2020-23 - Coronavirus

[YmoBeThere]

The VDH website shows a daily case reporting of over 2000. Any idea why VA had it's biggest day ever? Nearly twice what it has been?

Check the testing numbers. We have seen similar things here in Texas. Numbers trend nicely, then they realize the missed some tests or a lab clears its backlog. Then you see big spikes.

[Nrrrrvous]

Check the testing numbers. We have seen similar things here in Texas. Numbers trend nicely, then they realize the missed some tests or a lab clears its backlog. Then you see big spikes.

I checked the testing numbers and they were not out of line of where they had been.

OK, I just found an article from this morning that says that we had some backlog, cases that were supposed to have been reported Tuesday and Wednesday. I guess that makes me feel a little better...

Linky

[freshmanjs]

https://www.washingtonpost.com/graph...ge%2Fstory-ans

Interesting (but grim) read on how long it might take us to reach herd immunity..short answer according to this analysis, is roughly 3 million deaths in the U.S...

This analysis seems to be ignoring the emerging (and empirically observed ) view that many people (maybe 50% or more) already have some level of immunity.

To the extent this is true, we are much closer to herd immunity than the analysis concludes.

[Skydog]

This analysis seems to be ignoring the emerging (and empirically observed ) view that many people (maybe 50% or more) already have some level of immunity.

To the extent this is true, we are much closer to herd immunity than the analysis concludes.

I haven't seen the evidence that up to 50% of our population has some immunity. Do you have a link? But I do suspect there is some kind of residual low level immunity in the spots that were clobbered early on (NY, Italy, etc.). It's hard for me to believe that the current low case rates of NY and NJ are entirely due to their disciplined behavior. In fact I'm pretty sure NJ has never ever been accused of exemplary behavior!

[cspan37421]

I haven't seen the evidence that up to 50% of our population has some immunity. Do you have a link?

I just found this:

https://www.sciencealert.com/common-...s-for-covid-19

But I think "immunity" is not the same as "an immune response"

[freshmanjs]

I haven't seen the evidence that up to 50% of our population has some immunity. Do you have a link? But I do suspect there is some kind of residual low level immunity in the spots that were clobbered early on (NY, Italy, etc.). It's hard for me to believe that the current low case rates of NY and NJ are entirely due to their disciplined behavior. In fact I'm pretty sure NJ has never ever been accused of exemplary behavior!

https://www.nytimes.com/2020/08/06/health/coronavirus-immune-cells.html

[freshmanjs]

I just found this:

https://www.sciencealert.com/common-...s-for-covid-19

But I think "immunity" is not the same as "an immune response"

It’s not known yet what level of immunity these people have, if any. However, in closed systems like the early cruise ships, less than half of people ever got Covid-19. It is possible there is part of the population with existing immunity. If that is true, it changes the herd immunity calculus a lot. TBD.

[Kdogg]

Very good points that had occurred to me as well, wondering how the UK laws might affect this...hey Kdogg, ever been to the Coal Hole? Yes, pubs could be prime recruiting grounds, especially after midnight...

That neck of the woods is too posh for me.

This analysis seems to be ignoring the emerging (and empirically observed ) view that many people (maybe 50% or more) already have some level of immunity.

To the extent this is true, we are much closer to herd immunity than the analysis concludes.

I just found this:

https://www.sciencealert.com/common-...s-for-covid-19

But I think "immunity" is not the same as "an immune response"

It’s not known yet what level of immunity these people have, if any. However, in closed systems like the early cruise ships, less than half of people ever got Covid-19. It is possible there is part of the population with existing immunity. If that is true, it changes the herd immunity calculus a lot. TBD.

I've been following these reports the last few day. It would help explain the 40-50 percent of people that are asymptomatic. Of course the standard disclaimers apply (early results, small samples, no peer review). I wonder if there are two sides to this coin. Could this explain both the people who have mild cases AND the people who have severe cases caused by cytokine storms. In one case the immune system triggers a quick normal response and in the other it triggers a five alarm fire response.

[CDu]

It’s not known yet what level of immunity these people have, if any. However, in closed systems like the early cruise ships, less than half of people ever got Covid-19. It is possible there is part of the population with existing immunity. If that is true, it changes the herd immunity calculus a lot. TBD.

While I agree that there is the potential for some degree of existing "immunity" (especially in Asian countries where SARS hit hard), I don't think that the cruise ships are strong evidence that it is anywhere close to 50%. Nor do I think the study you referenced is evidence of immunity. The article acknowledges that these T-cells may be beneficial, may be detrimental, and may have no impact. And if beneficial, they may be effective in preventing the infection or making a case more mild.

As for the cruise ship, the fact that less than half got infected doesn't necessarily mean much. Not everyone interacts with everyone on a cruise ship to begin with. The interactions are somewhat constrained: you dine with the same folks each night, and usually split into 2-3 dining groups. Beyond that, excursions and interactions are again largely grouped. Beyond that, any interactions between any two non-connected people is likely to be brief and infrequent. So while the risk of infection is certainly higher when constrained to a cruise ship than in a general population setting, especially for large indoor gatherings, one wouldn't expect it to approach 100% risk.

There certainly COULD be a substantial degree of immunity in the population. And I certainly hope so. But I don't think we have any idea how likely/widespread it is, nor how beneficial it would be.

I've been following these reports the last few day. It would help explain the 40-50 percent of people that are asymptomatic. Of course the standard disclaimers apply (early results, small samples, no peer review). I wonder if there are two sides to this coin. Could this explain both the people who have mild cases AND the people who have severe cases caused by cytokine storms. In one case the immune system triggers a quick normal response and in the other it triggers a five alarm fire response.

Yes, the article alludes to the possibility that they could also be harmful. If the T-cells trigger an immune response, they could also presumably trigger the cytokine storm. We just don't know enough yet.

[freshmanjs]

While I agree that there is the potential for some degree of existing "immunity" (especially in Asian countries where SARS hit hard), I don't think that the cruise ships are strong evidence that it is anywhere close to 50%. Nor do I think the study you referenced is evidence of immunity. The article acknowledges that these T-cells may be beneficial, may be detrimental, and may have no impact. And if beneficial, they may be effective in preventing the infection or making a case more mild.

As for the cruise ship, the fact that less than half got infected doesn't necessarily mean much. Not everyone interacts with everyone on a cruise ship to begin with. The interactions are somewhat constrained: you dine with the same folks each night, and usually split into 2-3 dining groups. Beyond that, excursions and interactions are again largely grouped. Beyond that, any interactions between any two non-connected people is likely to be brief and infrequent. So while the risk of infection is certainly higher when constrained to a cruise ship than in a general population setting, especially for large indoor gatherings, one wouldn't expect it to approach 100% risk.

There certainly COULD be a substantial degree of immunity in the population. And I certainly hope so. But I don't think we have any idea how likely/widespread it is, nor how beneficial it would be.



Yes, the article alludes to the possibility that they could also be harmful. If the T-cells trigger an immune response, they could also presumably trigger the cytokine storm. We just don't know enough yet.

The cruise ship was held for weeks, with people sharing circulated air. It's not a perfect transmission system, but it's a much better one than the normal cruise environment you describe. There are also examples of crews that have been stuck on ships for months, and still there is a portion of the population that never gets it.

I'm not claiming it is proof of anything. However, many people act like it is 100% given that if we let the thing play out, everyone will get it and millions of Americans will die. That is also far from clear.

[CDu]

The cruise ship was held for weeks, with people sharing circulated air. It's not a perfect transmission system, but it's a much better one than the normal cruise environment you describe. There are also examples of crews that have been stuck on ships for months, and still there is a portion of the population that never gets it.

I'm not claiming it is proof of anything. However, many people act like it is 100% given that if we let the thing play out, everyone will get it and millions of Americans will die. That is also far from clear.

I agree that it isn’t clear exactly how many will die if we just let it play out. I feel pretty comfortable that it would be over 500,000 given where we are right now (10% seroprevalence, 160,000 dead, and that is with restrictions and some lockdowns). Even if herd immunity is achieved as low as 33% (or if immune responses help reduce mortality to effectively work like that) that’d still be over 500,000 deaths. But “millions” is certainly more questionable. We don’t know about immune responses to mitigate damage. We don’t know what true herd immunity is. Conversely, we don’t know how bad things would get in terms of places exceeding healthcare resource capacity again like we saw in Italy and NYC.

Regardless, I hope that eventual treatments and vaccines come through soon enough that we don’t have to test whether it is 300k, 500k, 1M, 2M, or 3M.

[freshmanjs]

I agree that it isn’t clear exactly how many will die if we just let it play out. I feel pretty comfortable that it would be over 500,000 given where we are right now (10% seroprevalence, 160,000 dead, and that is with restrictions and some lockdowns). Even if herd immunity is achieved as low as 33% (or if immune responses help reduce mortality to effectively work like that) that’d still be over 500,000 deaths. But “millions” is certainly more questionable. We don’t know about immune responses to mitigate damage. We don’t know what true herd immunity is. Conversely, we don’t know how bad things would get in terms of places exceeding healthcare resource capacity again like we saw in Italy and NYC.

Regardless, I hope that eventual treatments and vaccines come through soon enough that we don’t have to test whether it is 300k, 500k, 1M, 2M, or 3M.

I agree with all of that. I was referring to the analysis posted earlier today that said 3M deaths will happen before we reach herd immunity.

[CDu]

I agree with all of that. I was referring to the analysis posted earlier today that said 3M deaths will happen before we reach herd immunity.

To be fair, that one post/article is not “many people acting like it is 100% certain” that it would be millions of deaths. It was one article (and not from a scientific journal), posted by one person (who questioned the numbers too), and one potential result given two specific assumptions (1.5% mortality and 60% threshold for herd immunity). I think your argument painted with too broad a brush.

[freshmanjs]

To be fair, that one post/article is not “many people acting like it is 100% certain” that it would be millions of deaths. It was one article (and not from a scientific journal), posted by one person (who questioned the numbers too), and one potential result given two specific assumptions (1.5% mortality and 60% threshold for herd immunity). I think your argument painted with too broad a brush.

That article is one example of a type of argument that many people have made, on this board and more broadly. Happy to compile a list of additional examples as helpful.

[CDu]

That article is one example of a type of argument that many people have made, on this board and more broadly. Happy to compile a list of additional examples as helpful.

Well, you haven’t yet provided one example of someone saying it is 100% certain that herd immunity would require millions of deaths. So, yeah “type of argument” is a bit different than what you said. Hence, my statement that you are painting with too broad a brush. At least as it relates to DBR.

Are there plenty of people with pessimistic views of what is going on? Absolutely. Is it possible that some are being OVERLY pessimistic? No doubt. Are there people who think it is certain that herd immunity equals millions of deaths? Quite possibly.

But I sincerely doubt you’ll find evidence supporting your quote, anymore so than your quote wasn’t meant to be 100% literal. So if you are going to defend your statement as “just a type of argument”, you probably should extend the same latitude to those posting pessimistic views you disagree with.

[tbyers11]

That neck of the woods is too posh for me.




I've been following these reports the last few day. It would help explain the 40-50 percent of people that are asymptomatic. Of course the standard disclaimers apply (early results, small samples, no peer review). I wonder if there are two sides to this coin. Could this explain both the people who have mild cases AND the people who have severe cases caused by cytokine storms. In one case the immune system triggers a quick normal response and in the other it triggers a five alarm fire response.

As the linked paper suggested SARS-CoV-2 CD4 T cells cross-reactive to common coronavirus epitopes in 20-50% of people assessed could lead to some people having varying degrees of immunity to SARS-CoV2 infection. These type of pre-existing T cell responses could lead to asymptomatic people or possibly to deleterious cytokine storms but most likely it would lead to people having more mild symptoms upon infection with SARS-CoV-2. When your T cells have encountered a pathogen they typically generate a more targeted, efficient immune response. The mapping of the exact types of response (central/effector memory classifications in Figures 2 and 3 and their ability to make IFN-g in Figure 4) are in line with a normal, helpful response.

This is not uncommon. In an earlier post, I mentioned that cross-reactive CD4 T cells to previous H1 influenza infections/vaccinations led to milder symptoms than expected in many people who were infected the H1N1 swine flu in 2009. This however is the first time that the exact cross-reactivity between SARS-CoV-2 and common corona viruses has been detailed so closely.

This is a good news and may explain why some people barely get sick when infected with SARS-CoV-2 but it does not mean that we have 20-50% herd immunity. Most recent estimates I have seen are 12-15% infected in the US. You need to be exposed (or vaccinated) to SARS-CoV-2 to likely generate enough immunity to have sufficient protection to re-exposure. A combination of antibody and T cell responses are usually required to do this. As noted in the article, the neutralizing Ab responses thought to be likely for SARS-CoV-2 protection to not appear to be cross-reactive to common corona viruses.

[YmoBeThere]

I checked the testing numbers and they were not out of line of where they had been.

OK, I just found an article from this morning that says that we had some backlog, cases that were supposed to have been reported Tuesday and Wednesday. I guess that makes me feel a little better...

Linky

Trying to track the flow of test result data has been frustrating. Along with flow issues, understanding the data gets confounded by various definitions used by different groups. Local officials here report based on CDC guidelines, the state doesn't. Which has caused several sizable shifts in the timing and volume of data.

After switching from an old to a new system here in Texas, San Antonio's rolling 7 day average new casrs went from 780 to 332. Interesting. It is difficult to be comfortable with the data we are getting..

[freshmanjs]

Well, you haven’t yet provided one example of someone saying it is 100% certain that herd immunity would require millions of deaths. So, yeah “type of argument” is a bit different than what you said. Hence, my statement that you are painting with too broad a brush. At least as it relates to DBR.

Are there plenty of people with pessimistic views of what is going on? Absolutely. Is it possible that some are being OVERLY pessimistic? No doubt. Are there people who think it is certain that herd immunity equals millions of deaths? Quite possibly.

But I sincerely doubt you’ll find evidence supporting your quote, anymore so than your quote wasn’t meant to be 100% literal. So if you are going to defend your statement as “just a type of argument”, you probably should extend the same latitude to those posting pessimistic views you disagree with.

I never claimed or believed anyone said that it is 100% certain herd immunity would require millions of deaths. Not going to look for or find evidence to support a “quote” that I never said.

[CDu]

I never claimed or believed anyone said that it is 100% certain herd immunity would require millions of deaths. Not going to look for or find evidence to support a “quote” that I never said.

“However, many people act like it is 100% given that if we let the thing play out, everyone will get it and millions of Americans will die. That is also far from clear.”

That quote is close enough. My point stands.

[cato]

The cruise ship was held for weeks, with people sharing circulated air. It's not a perfect transmission system, but it's a much better one than the normal cruise environment you describe. There are also examples of crews that have been stuck on ships for months, and still there is a portion of the population that never gets it.

I'm not claiming it is proof of anything. However, many people act like it is 100% given that if we let the thing play out, everyone will get it and millions of Americans will die. That is also far from clear.

What do you think will happen if we let thing play out?