Just using those two early hard hit countries as examples, I look at their charts of new cases by day and see that have dropped to very low levels (compared to the peaks). Spain was running as high as 8000 new cases a day in late March or early April, and now around 600 a day. Italy peaked at 6000 new cases a day late March and now around 700 new cases per day.

If you just look at their total number of people who have had confirmed positive tests, it is a very low percentage of total population, around 0.6% for Spain with confirmed positive test results. Based on just that number, clearly no where close to enough people with immunity to stop or slow the spread of the disease.

I also think that Spain and Italy have had various lockdown policies changing as far back as late April. I admit I don't know the extent of those changes or functional impact. But I see the new cases remain very low and continue to fall.

SO, what do we attribute the big drop to? I see potentially:

• This virus has a seasonal behavior to it
• So many more people have actually had it and developed antibodies than just those with confirmed positive tests, that some degree of mass immunity has slowed the spread
• The lockdowns are very effective in stopping the spread and there really isn't much that has reopened or changed as far as those lockdown policies in Spain and Italy.

In Texas, I've seen an increase in activity each week since the third week of April. People in my office building not wearing masks, people working the counter in a high traffic Fedex not wearing masks, a guy making burritos in Chipotle a couple days ago had no mask or gloves. Lots more people out and about. However, I don't see an increase in cases yet - is it just slow to occur and it starts in a few weeks?

I guess I am concerned it is seasonal and my hopes for school for my kids and attending sporting events for myself in the Fall will all fall apart when cases rise dramatically at that time. Optimistically I hope there are enough antibodies in enough people to slow things, or perhaps mutations are occurring in the virus making it harder to spread or less likely to sicken people.

THoughts?

There are a ton of people with antibodies who never had symptoms. Also, would you have felt better if the guy at chipotle was wearing gloves? If so, why?

4 - some percentage of the population is inherently "immune" due to either pat antibodies, overall health, etc., so that they will not get it from a small exposure.

So in addition to the huge number of asymptomatic people that have it, there is another large pool that never got it and won't ever get it.

I have no idea how you felt about gloves, that's why I asked. Last time I was at a chipotle there was one guy working in the front and one guy cooking in the back. The guy in front wore gloves as I watched him touch my food, spoon handles, refrigerator handles, the cash register and my money before returning to make the next guys burrito. The gloves made me feel extra safe.

To answer your question, it's a mix of things. Herd immunity isn't something that switches on at a certain percentage. It's gradual. Plus lockdowns and general awareness by the population helps. Summer hopefully helps too. Gloves not so much.

Probably a bit of all 3 you mentioned. Would be awesome if the virus was fizzling some in terms of contagiousness or strength, too. But that's wishful thinking.

Why is SARS and mers not seasonal?

I really want to know, wasn't a smart ass rhetorical.

The guy did have a mask on - but it was only covering his chin and not his mouth or nose. I have to think gloves in food service are a requirement right now, so one way to look at it is I like people following the requirements for the job. However, another way to look at is my final vote on the matter - I ate the burrito.

That's my fear and I would hate to see a huge spike of cases in the Fall since I think I know what that will do to all of our activities.

Someone else said thinking it could be virus mutation is wishful thinking - yes, that is my wishful thinking. Much preferable to some Fall return.

If flu cases start popping up in October... you can bet that even if they aren't positive COVID tests... that we will have calls for lockdown on the premise that COVID will soon happen inevitably.

We have created a monster.

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The lockdowns are very effective in stopping the spread and there really isn't much that has reopened or changed as far as those lockdown policies in Spain and Italy.

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In spain, you can still get fined and or arrested for going out without a valid reason like Groceries, pharmacy, or your 1 walk a day.

JamesE4 said:

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4 - some percentage of the population is inherently "immune" due to either pat antibodies, overall health, etc., so that they will not get it from a small exposure.

So in addition to the huge number of asymptomatic people that have it, there is another large pool that never got it and won't ever get it.

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This is a point that has not been raised enough.
While folks will talk about this being a novel disease with no immunity there is going to be a substantial genetic pool that will have natural immunity to any number of disease that may not exist during the natural selection of the trait.

We do not know this number, but we may learn that it is substantial. So building off of this the herd immunity "exposure" % may need to be 60% or what ever, but that exposure should drastically be reduced if there is already a naturally immune population built in.

KlinkerAg11 said:

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Why is SARS and mers not seasonal?

I really want to know, wasn't a smart ass rhetorical.

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My cursory understanding is these viruses are predominately spread these days by animal-to-human transmission rather than human-to-human. In the case of MERS, camels are the viral reservoir, SARS is thought to be bats.

Pumpkinhead said:

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Spain and Italy dropped the HAMMER in locking down their populations. No traveling farther than a kilometer from your home - travel within the country heavily restricted, not even jogging allowed, maximum of 2 people allowed in a car and the second person had to ride in back, masks mandatory if outside home, only allowed to be out for 'essential' reasons such as grocery store...etc.

Spain and Italy didn't do 'Shelter-In-Place' like the U.S. They implemented full LOCKDOWN. Your average American would have flipped the f*** out much more than with the S.I.P. policies had the U.S. tried to lock them down like Italy and Spain did to their populations. Actually, a lot of Italians and Spaniards flipped the f*** out.

Not going to advocate for or against that extreme, but logical thinking said sure, though torpedoing their economies, that dramatically slowed the spread rate of COVID.

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OK, thanks for the info on their policies. Are they opening back up now? I saw plans for school to begin in May in Spain, so I'll keep an eye on their case count. I had thought they perhaps were relaxing their restrictions 2-4 weeks ago. I thought I had seen articles stating as much about Italy anyway.

I looked at another country that was an early hot spot - Iran. And I was surprised to see a peak case count of 3000 new cases a day in late march and then a drop to around 800 cases a day near the beginning of May. However, in the last 3 weeks I see it rising again (https://www.worldometers.info/coronavirus/country/iran/) back to 2200 per day or so. So I looked and it appears they lifted some restrictions in Mid April. I guess this would support the lock down as the main contributor see rises and declines in new case counts. It might also suggest it will take until early June for Texas to see any increases in new counts per day.

Germany, France and Belgium look like Italy and Spain - very large reductions since their peaks and at low points now. The UK looks more like the US, although it is reduced from the peak it isn't much. Very slight trend slope down. Perhaps this can also be tied to the approach to restrictions in each country?

Nothing short of some reliable vaccine or treatment may allow us fully back to a relaxed normal, but I was hoping that a decline like that seen in most European countries would persist even as we ease things up as far as interacting with each other and moving about.

I posted this back on April 1st, I really thought more people would have had the illness by now though:

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As we have seen the virus hit the Texas and Texags communities, it dawned on me that more and more people will have
1) Personally had it and gotten over it
2) Known someone who had it and gotten over it, both mild or even asymptomatic cases if antibody testing is rolled on on a huge and accurate scale

I think as the number of people in each category grows, fear will subside. I think by that time we'll a much clearer data picture, gathered in our own country, to work with as well. As a result, sheltering of individuals will be more targeted and those that have the option to go out or work, but are afraid to, will start to go out. So, kind of driven by public sentiment and good data.

If you believe the graphs showing when this would peak and subside, you would think by mid to late May we would then see things open up. But I struggle to believe those curves - nearly every infection and every death will happen in next 8 weeks? We will see.

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I'm not sure how useful comparing countries worldometer numbers. Does anyone believe the numbers from Iran/China/Russia? Russia reports 317,000 cases and 3,099 deaths compared to the U.K. with 250,908 cases and 36,042 deaths? Even within EU countries, why does Germany have the basically the same number of cases as France but only 8,309 deaths compared to 28,215?

As long as the numbers are being collected with varying methods, comparisons don't seem useful to me.

I wouldn't use Russia or China but for the other countries my point wAs not comparing overall rates between the countries, but rather new case trends within the same country. I do assume that within the same country what they consider a valid new case has not varied. So if in that country new case rates decline it's a valid measure against the prior numbers within the country. The main thing impacting the new case numbers is the total tests administered, early on new cAses were self limiting by lack of testing but those that got testing were more likely to be the ones with covid symptoms or in contact with those that had covid.

I still think the trends have value within a country but admit it's not a perfect measure of actual rate of illness.

I agree to some extent and you're right about testing being a major issue affecting how the trends look. Texas is a good example, as new cases have plateaued but with the massive increase in testing what does it really mean? I saw on the worldometer site that Grayson county just reported like 150 new cases today, for a total of 268. Is there a new outbreak or a round of new testing?

GAC06 said:

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I agree to some extent and you're right about testing being a major issue affecting how the trends look. Texas is a good example, as new cases have plateaued but with the massive increase in testing what does it really mean? I saw on the worldometer site that Grayson county just reported like 150 new cases today, for a total of 268. Is there a new outbreak or a round of new testing?

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Grayson County has several different factories located there. I know that two of them have had some Covid-19 cases in the past few weeks- Tyson and Ruiz Foods. So, I assume some of the new cases today could be some of the factory workers and relatives of the factory workers. My sister owns some rental homes in Sherman and Denison. Three of her renters work at the above factories, so she has been following the cases there.

Herd immunity is somewhere around 70-90%. There isnt any country that is much beyond 5% right now.

That's not a concept that is going to be relative for a very long time.

GAC06 said:

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That's the first I've heard of herd immunity requiring 90%. In articles on Sweden their experts were focused on 40-50%, and really only in Stockholm. In rural areas I don't see it mattering as much since it can't spread that fast there anyway.

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Also, every increase in immunity in a population increases the effectiveness of all other strategies. Or, more precisely, it makes you have to rely less on other strategies.

We could knock out 15-20% of the population from being spreaders relatively quickly simply by letting preschool-college go back to class unimpeded.

GAC06 said:

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That's the first I've heard of herd immunity requiring 90%. In articles on Sweden their experts were focused on 40-50%, and really only in Stockholm. In rural areas I don't see it mattering as much since it can't spread that fast there anyway.

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I got that from this article and listening to the former FDA director on CNBC.

https://www.cnn.com/2020/05/21/health/sweden-herd-immunity-coronavirus-intl/index.html

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Sweden has revealed that despite adopting more relaxed measures to control coronavirus, only 7.3% of people in Stockholm had developed the antibodies needed to fight the disease by late April.

The figure, which Sweden's Public Health Authority confirmed to CNN, is roughly similar to other countries that have data and well below the 70-90% needed to create "herd immunity" in a population.

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GAC06 said:

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That's the first I've heard of herd immunity requiring 90%. In articles on Sweden their experts were focused on 40-50%, and really only in Stockholm. In rural areas I don't see it mattering as much since it can't spread that fast there anyway.

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There are two points of importance with herd immunity:

• The % of population that need to be immune to slow the spread of the virus
• The % of the population that end up getting the virus before it goes away.

The first number is calculated by (R0-1)/R0, which is where the virus approximately peaks, which is 50% for a R0 of 2.

The 2nd number is important to understanding the human cost of reaching herd immunity. For an R0 of 2, 80% of the population end up getting it.

For R0 of 3, its 66.7% and 91%.

I recommend looking at this 538 simple model where you can plug in R0, IFR, and immunity time to see how it works.