DadHammer said:

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I am not following your point here. Why do you not think it's 20-30 %? Most data we have seen here suggests that range. It doesn't mean no infections. The numbers in Houston aren't even high enough to be considered a pandemic anymore are they? We are already down to 33% of the peak rate of hospitalizations. There have been no reinfections that I have seen to date. If there are any they are tiny to ignorable numbers so far. Number of infections mean nothing if the hospitalizations falling substantially. Just look at NY's numbers, they have obviously passed herd immunity long ago.

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There are a few points here...

-The question isn't why I think herd immunity for this virus is not 10%-20%-30%, that would be great(!), but rather why should that be the case against established epidemiology. A disgruntled Nobel laureate mathematician frankly means not a lot - everyone has an opinion and an ******* and they're worth the same (including this post). As more studies and data comes in we may discover something new that changes science in the field, but to date you're talking about a handful of studies trying to make sense of something that is a big unknown. Still, we can hope and there is some interesting data for cause for hope just while acknowledging "hope" isn't a great planning strategy.

-This is a message board with a dozen or so doctors posting and bunch of us trying to figure it out. More people are here for understanding and comfort than rigorous scientific critique.

-Houston hospitalizations going down is great news! It's what we want and hope to have happen. By no means is it by accident - the trends we see today are a result of personal and general public measures taken 4, 5, and 6 weeks ago. Hypothetically, should those measures instantly cease and all of greater Houston go back to life as usual pre-COVID then the same pattern and ICU overflow we saw in June/July would happen... On a positive note, I think we have all observed that people have changed and simple control measures seem to be pretty much universal - I put very low odds on repeating the "Memorial Day Effect" provided that.

-NYC is still dramatically changed from normal life. I talk to family and friends who live in Manhattan about it weekly. Arguably those measures and their huge multi-week unmitigated spread in March are keeping the R(t) in check. It isn't "real" herd immunity, though I definitely suspect that broader population immunity is starting to have an effect - - it's policy action and widespread social adhesion to mitigation measures that are driving current trends. If they back off the simple personal responsibility stuff, they would see a surge in new cases and probably faster and worse just given the reality of density and public transit there.


As an aside, a little heads up for y'all travel bugs - look at flights to NYC between now and Thanksgiving. I've booked 6 round trip weekends for less than $50/ea. Best so far is $26 round trip to Newark on United. Don't even need to jack around with Spirit Airlines for that.

Fitch said:

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DadHammer said:

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I am not following your point here. Why do you not think it's 20-30 %? Most data we have seen here suggests that range. It doesn't mean no infections. The numbers in Houston aren't even high enough to be considered a pandemic anymore are they? We are already down to 33% of the peak rate of hospitalizations. There have been no reinfections that I have seen to date. If there are any they are tiny to ignorable numbers so far. Number of infections mean nothing if the hospitalizations falling substantially. Just look at NY's numbers, they have obviously passed herd immunity long ago.

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There are a few points here...

-The question isn't why I think herd immunity for this virus is not 10%-20%-30%, that would be great(!), but rather why should that be the case against established epidemiology. A disgruntled Nobel laureate mathematician frankly means not a lot - everyone has an opinion and an ******* and they're worth the same (including this post). As more studies and data comes in we may discover something new that changes science in the field, but to date you're talking about a handful of studies trying to make sense of something that is a big unknown. Still, we can hope and there is some interesting data for cause for hope just while acknowledging "hope" isn't a great planning strategy.

-This is a message board with a dozen or so doctors posting and bunch of us trying to figure it out. More people are here for understanding and comfort than rigorous scientific critique.

-Houston hospitalizations going down is great news! It's what we want and hope to have happen. By no means is it by accident - the trends we see today are a result of personal and general public measures taken 4, 5, and 6 weeks ago. Hypothetically, should those measures instantly cease and all of greater Houston go back to life as usual pre-COVID then the same pattern and ICU overflow we saw in June/July would happen... On a positive note, I think we have all observed that people have changed and simple control measures seem to be pretty much universal - I put very low odds on repeating the "Memorial Day Effect" provided that.

-NYC is still dramatically changed from normal life. I talk to family and friends who live in Manhattan about it weekly. Arguably those measures and their huge multi-week unmitigated spread in March are keeping the R(t) in check. It isn't "real" herd immunity, though I definitely suspect that broader population immunity is starting to have an effect - - it's policy action and widespread social adhesion to mitigation measures that are driving current trends. If they back off the simple personal responsibility stuff, they would see a surge in new cases and probably faster and worse just given the reality of density and public transit there.


As an aside, a little heads up for y'all travel bugs - look at flights to NYC between now and Thanksgiving. I've booked 6 round trip weekends for less than $50/ea. Best so far is $26 round trip to Newark on United. Don't even need to jack around with Spirit Airlines for that.

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You say NYC is changed dramatically. I've been curious if everyone their wears masks, works from home, stays home. Are bars still closed, restaurants 50% occupancy, parks not crowded. Just how limited is personal contact there? When it began to get warmer there and their virus spread abating, we saw images of parks with many people out and about in groups. Have things like that continued and grown to be more common or is everyone sitting inside?

Those are great air fares for sure. Got a flight to Pensacola for about $110 round trip.

If they drop FB wife and I will be traveling all fall. Playa will be next.

You post some good reasons for your conclusions. I just came to slightly different ones.

This thread has turned into the herd immunity vs mitigation debate. Can we get back to data or is that the problem, we no longer have good data?

Appreciate the dialogue.

People are still living life and socializing, but the "how" looks much different. Lots of street seating and closed traffic lanes because dining indoors isn't allowed, dramatically reduced density on public transit, no clubs, bars, theaters or malls open. Frankly a lot of the reasons NYC is fun are still shuttered.

White collar commuter traffic has evaporated as firms opt to keep working remote until next spring.

Normal summer time vacationing still going on but now "quarantine teams" are setup at major entry points.

We be nice to see a big study on Sweden's current antibody and T cell covid count.

The virus is super low now and not in pandemic levels and hasn't been for a long time.

Would be great data to have. They supposedly are keeping Tight records looking for reinfections and haven't
Reported any yet. That is and would be a major victory for the human body against future covid outbreaks making them more like a common cold and not a pandemic ever again.

Also I don't mind sitting outside at all, I actually prefer it when we go out. We haven't gone out much lately as the wife and I have gained too many beer pounds since this thing started!

Edit to clarify - the fatalities curves are inaccurate for the trailing ~2-3 weeks. As data comes in from across the state the daily counts are revised and the shape of the curve changes.

Fitch said:

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People are still living life and socializing, but the "how" looks much different. Lots of street seating and closed traffic lanes because dining indoors isn't allowed, dramatically reduced density on public transit, no clubs, bars, theaters or malls open. Frankly a lot of the reasons NYC is fun are still shuttered.

White collar commuter traffic has evaporated as firms opt to keep working remote until next spring.

Normal summer time vacationing still going on but now "quarantine teams" are setup at major entry points.

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So no indoor crowds, reduced public transportation crowding and reduced population density due to non-commuting workers. But outdoor activity may be greater. Are people generally wearing masks while outdoors or just while walking down the streets vs socializing or hanging out in the parks?

Haven't personally been to any NY area parks to see what the adherence is, but the masks mandate is for all times spent in public - including just walking down the street.

New TMC charts

Fitch said:

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Haven't personally been to any NY area parks to see what the adherence is, but the masks mandate is for all times spent in public - including just walking down the street.

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I'm sure things are a little different now, but in normal times it's kind of impossible to walk down a street in New York and not be within 6 feet of a bunch of people.

Fitch said:

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Haven't personally been to any NY area parks to see what the adherence is, but the masks mandate is for all times spent in public - including just walking down the street.

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Thanks for the update Fitch!

I'm curious how they are calculating R(t)

If you go to

https://sph.uth.edu/dept/bads/covid19-dashboard

there is the following:



Details of the statistical modeling

R(t) was estimated using the R0 package in R. The generation time estimates were generated using a gamma distribution with mean 3.96 and standard deviation 4.75, based on estimates from Ganyani, et al. 2020. We investigated several options based on the literature and found this choice of distribution and parameters to not affect the results significantly. Some of the R(t) estimates may be unreliable for counties with "data dumps". Interpret cautiously for these counties as we are not able to observe the trend over time. To smooth the data, we used 7-day moving averages in the R(t) estimation. Case reports are lagged from test administration (at the beginning the lag was closer to 2-3 weeks and by May it was closer to 2-5 days), thus what we currently are able to estimate is a reflection of tests performed several days prior. This lag may differ by county, hospital, and testing center. R(t) is only estimated for counties who have had at least 50 total cases.

Ganyani T, Kremer C, Chen D, Torneri A, Faes C, Wallinga J, Hens N. Estimating the generation interval for coronavirus disease (COVID-19) based on symptom onset data, March 2020. Eurosurveillance. 2020 Apr 30;25(17):2000257.

To build the predictions of new cases, an Auto regressive Integrated Moving Average (ARIMA) model was built on 7-day moving averages of new cases to predict 10-days in the future. The order of autoregression, degree of differencing, and moving average for the model was selected using the auto.arima function in R, selecting the best model based on the Aikake Information Criteria. If the number of max daily cases was too low, no estimates were produced. The limitations of these projections include: (1) these projections are built purely on previous data trends and do not account for any covariates at this time; (2) predictions may be unreliable for counties that have data dumps; (3) case reports are lagged from test administration (at the beginning the lag was closer to 2-3 weeks and by May it was closer to 2-5 days), thus what we currently are able to estimate is a reflection of tests performed several days prior. This lag may differ by county, hospital, and testing center.


for those playing along at home, here is a link to documentation of the R package they used
https://cran.r-project.org/web/packages/R0/R0.pdf

Our staff has been told to not discuss our actual numbers, and our hospital is refusing to publish data publicly thinking it would hurt business.

I can say that my hospital, east of Dallas, is also seeing a decline in new cases. Worked a shift last night on the Covid unit and we did not admit a single new Covid patient despite having an available bed, first time in two months that this has happened. They had a couple in the ER likely to admit today but the trend is pretty good. Unfortunately we haven't seen a decline in hospitalized patients, at least not a significant one. Very flat numbers over the last few weeks, hopefully we start the downtrend soon.

I've seen multiple obituaries of patients I've had over the last few weeks that we've had to send to ICU. Very sad.

Fitch said:

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Haven't personally been to any NY area parks to see what the adherence is, but the masks mandate is for all times spent in public - including just walking down the street.

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Check out Brooklyn. Most aren't really following that rule.

beerad12man said:

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Masks outdoors is insanity unless you are neck and neck with someone.

Edit: Just read it. It says when other social distancing measures cannot be met. So if you aren't within 6 feet of someone you don't need it. Just taking a morning walk without a mask on should be fine as long as you aren't getting right next to someone else.

https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covid-19-face-covering-faq.pdf

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Seems like it might be hard to walk the streets of NY and maintain 6 ft separation. Unless it looks drastically different than it did before COVID.

True but look at sevens post. Doesn't seem like they are all abiding by it

Either way. If you are just walking by someone, it seems like minimal exposure. Seems to me you'd need to be near an infected person for a few minutes to have a high likelihood of transmission, not just passing by them.

Yup.

San Antonio region is probably my favorite.

beerad12man said:

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True but look at sevens post. Doesn't seem like they are all abiding by it

Either way. If you are just walking by someone, it seems like minimal exposure. Seems to me you'd need to be near an infected person for a few minutes to have a high likelihood of transmission, not just passing by them.

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Yes. Probably a good 10-15 minutes for a high likelihood of transmission.

Thanks Fitch and others and appreciate the heads up on the fatalities charts....I was pretty excited when I first looked at them.

Clearly we are over the hump and headed down. How do we stay down is the key. And I'm not looking to open the debate on herd immunity vs mitigation.

But looking at the numbers there as clearly been some effective mitigation and I doubt it's wearing masks outdoors. I think everyone agrees transmission goes through the roof for close quarters + indoors/stagnant airflow. I'm sure close quarters + outdoors is not great, but I think it matters how stagnant the crowd and the air.

Considering this, seems the real focus of mitigation should be close quarters + indoors. It's why I think, as many do, closing the indoor bars and night clubs has had the greatest effect on mitigation. And I doubt wearing masks in these environments would have any material impact on transmission rates.

I've noticed the gym I go to has changed their protocol....initially, they were leaving all fans off, very stagnant inside.....now fans on full blast. Asking the people that work there it was recommended by "medical experts". A buddy of mine says his gym has done the same thing...different gym.

Is there science behind this and if so, why can't it be applied to all the indoor environments?

Rock1983 said:

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Thanks Fitch and others and appreciate the heads up on the fatalities charts....I was pretty excited when I first looked at them.

Clearly we are over the hump and headed down. How do we stay down is the key. And I'm not looking to open the debate on herd immunity vs mitigation.

But looking at the numbers there as clearly been some effective mitigation and I doubt it's wearing masks outdoors. I think everyone agrees transmission goes through the roof for close quarters + indoors/stagnant airflow. I'm sure close quarters + outdoors is not great, but I think it matters how stagnant the crowd and the air.

Considering this, seems the real focus of mitigation should be close quarters + indoors. It's why I think, as many do, closing the indoor bars and night clubs has had the greatest effect on mitigation. And I doubt wearing masks in these environments would have any material impact on transmission rates.

I've noticed the gym I go to has changed their protocol....initially, they were leaving all fans off, very stagnant inside.....now fans on full blast. Asking the people that work there it was recommended by "medical experts". A buddy of mine says his gym has done the same thing...different gym.

Is there science behind this and if so, why can't it be applied to all the indoor environments?

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Current guidance is poor ventilation is bad. You want exchange with fresh air. Not sure the set up at the gym, but if it is just turning on the fans in an otherwise poorly ventilated space, the fans aren't going to help. There are some studies showing air currents can push the droplets further than the 6 feet. On the other hand, if they have the doors/windows open, properly positioned fans can help in swapping indoor for outdoor air. A lot of commercial HVAC systems also pull in air from outside to blend with the return air. Increasing the amount of outside air could help.

EPA guidance on COVID & ventilation.

https://www.epa.gov/coronavirus/indoor-air-and-coronavirus-covid-19

Looking at the TMC data.....

Here is a comparison of Total Cases through the system vs Resolved Cases (Discharged or deceased)


And a calculation of how far behind the Resolved Case curve is from the Total Case curve.



The TMC data includes a running death toll. This chart shows the daily change in that number. The peak was July 21



The reported number of ICU cases peaked the next day.