Cont: The One Covid-19 Science and Medicine Thread Part 3

[Samson]

Its not a mistake per se. Herd immunity can be a function of a natural process. How do you think populations of humans survived plagues and pandemics before we had vaccines?

Herd Immunity occurs when you get a sufficiently large proportion of the population that are immune to a disease, such that non-immune infected members of the remaining population have little no chance of spreading the disease to other non-immune members of the same population. This is why you may have heard people talking about how the vaccinated population can protect those who cannot, or will not take the jabs.

Herd Immunity can be achieved by...

1. A vaccination programme
The efficacious use of widespread vaccination to increase the immunity of as many people as possible. This is how smallpox and polio were eradicated. This way costs the smallest number of lives - if Covid had been properly managed in the US before the vaccines became available, and vaccinations had not been politicised by the political right, we would be talking about less than 20,000 to 30,000 deaths in the US, instead of almost 700,000.

2. Let the virus run wild
Allowing the disease to spread so that your large proportion of the population become immune by getting the disease and surviving it. However, while this method might be financially cheaper, it would result in horrific toll in lives. The disease appears to have a morbidity rate in the US of between 1.4% and 1.6%. It has been estimated that natural herd immunity in the US could have cost between 4½ million and 5¼ million lives.
.
.

The term herd immunity was used for animals.
They all get vaccinated by force.

https://www.thelancet.com/journals/lancet/article/PIIS0140-67362031924-3/fulltext

 

[Aridas]

However, while this method might be financially cheaper, it would result in horrific toll in lives.

Just to add to this - cheaper in investment/direct costs. The increased financial losses to the society in the long term tend to end up dramatically greater than the cost of investing in public health would have been.

 

[The Atheist]

The disease appears to have a morbidity rate in the US of between 1.4% and 1.6%. It has been estimated that natural herd immunity in the US could have cost between 4½ million and 5¼ million lives.

You are completely wrong, and it's the exact same nonsense that idiot Hendy has been peddling in NZ with his baloney "7000 will die at 70% vaccination". Gosh, I'd think people were panicking by getting the numbers so wrong if I didn't know nobody was panicking.

Seroprevalence testing has shown that only a fraction of cases ever get tested. The best estimate is that there have been 5-20 times more people infected than the numbers being tested and collated.

In terms of actual fatality rate, the best study to date shows:

The median infection fatality rate across all 51 locations was 0.27% (corrected 0.23%).

And would you know it, that is being borne out around the world, where infection rates plummet once mortality hits 0.2% of the population.

Whatever your reason is for overstating the case I have no idea, but it's woefully wrong.

 

[Bubba]

You are completely wrong, and it's the exact same nonsense that idiot Hendy has been peddling in NZ with his baloney "7000 will die at 70% vaccination". Gosh, I'd think people were panicking by getting the numbers so wrong if I didn't know nobody was panicking.

Seroprevalence testing has shown that only a fraction of cases ever get tested. The best estimate is that there have been 5-20 times more people infected than the numbers being tested and collated.
In terms of actual fatality rate, the best study to date shows:

The median infection fatality rate across all 51 locations was 0.27% (corrected 0.23%).

And would you know it, that is being borne out around the world, where infection rates plummet once mortality hits 0.2% of the population.

Whatever your reason is for overstating the case I have no idea, but it's woefully wrong.

Sometime last year a town in California tested all their citizens. I dont recall the town, or the estimated rate before testing everyone vs the rate found after testing everyone, but the number of positives was far higher than anyone thought it would be.

 

[smartcooky]

https://coronavirus.jhu.edu/data/mortality

Country | Confirmed | Deaths | Case-Fatality | Deaths/100K pop.

United States | 42,853,724 | 687,084 | 1.6% | 209.32

I would just like to point out that these are actual recorded figures, as in, real things that actually happened, not some "estimate" of what might happen.

Real figures trump estimates.. every . single . time! Anyone who disagrees, take it up with Johns Hopkins University (contact details in the link).

And just to restate, for the benefit of those with reading or comprehension difficulties...

"Allowing the disease to spread so that your large proportion of the population become immune by getting the disease and surviving it. However, while this method might be financially cheaper, it would result in horrific toll in lives. The disease appears to have a morbidity rate in the US of between 1.4% and 1.6%. It has been estimated that natural herd immunity in the US could have cost between 4½ million and 5¼ million lives.

This literally means allowing it to spread unchecked. I was making the case for how herd immunity was arrived at in the past... no treatment, no vaccines, no respirators, treating it as if it was untreatable, when all they could do was make people as comfortable as they could, and they either survived or died.

 

[Planigale]

Its not a mistake per se. Herd immunity can be a function of a natural process. How do you think populations of humans survived plagues and pandemics before we had vaccines?

Herd Immunity occurs when you get a sufficiently large proportion of the population that are immune to a disease, such that non-immune infected members of the remaining population have little no chance of spreading the disease to other non-immune members of the same population. This is why you may have heard people talking about how the vaccinated population can protect those who cannot, or will not take the jabs.

Herd Immunity can be achieved by...

1. A vaccination programme
The efficacious use of widespread vaccination to increase the immunity of as many people as possible. This is how smallpox and polio were eradicated. This way costs the smallest number of lives - if Covid had been properly managed in the US before the vaccines became available, and vaccinations had not been politicised by the political right, we would be talking about less than 20,000 to 30,000 deaths in the US, instead of almost 700,000.

2. Let the virus run wild
Allowing the disease to spread so that your large proportion of the population become immune by getting the disease and surviving it. However, while this method might be financially cheaper, it would result in horrific toll in lives. The disease appears to have a morbidity rate in the US of between 1.4% and 1.6%. It has been estimated that natural herd immunity in the US could have cost between 4½ million and 5¼ million lives.
.
.

The problem is at best this is simplistic, and at worst wrong.

To start with natural herd immunity from a natural infection. This is only true where an infection results in enduring immunity that prevents people being infectious. Most natural infections that circulate do not do this. Many infections you can get more than once and can transmit. Even if immune (ie preventing symptomatic disease) you can transmit the virus. Herpes viruses might be an example. Coronaviruses and RSV circulate because immunity is not enduring, if you have had TB once you are more likely to get it again (you are a susceptible host).

Lets move on to vaccines. vaccines may prevent symptomatic disease, but not infection. Take TB, vaccination significantly reduces the risk of getting severe forms of TB such as meningitis. It does not stop you getting infected, but limits the infection to the lung. But it is lung infection that is the infectious form of TB, so paradoxically by limiting infection to the lung TB vaccination has little impact on transmission. Below is a nice paper on flu vaccination in pigs, the vaccines stop pigs becoming unwell but do not stop them transmitting the virus. That is to say vaccinated pigs still become infected, the virus replicates in the nose and they shed infectious virus particle, but it seems to prevent pneumonia.

Some vaccines are effective at preventing or reducing transmission, small pox, polio, but remember these are used in isolation other measures such as quarantining are also used in control and eradication of infections.

Plague is a poor example as an arthropod borne zoonotic. The herd immunity would need to occur in the rats or fleas. Person to person transmission is not a significant issue with plague. Plague outbreaks do not decline because of the development herd immunity in people, because transmission is not person to person.

Finally of course we would not know about infections where natural herd immunity occurred, because they would no longer be circulating. English sweating sickness might be one since it simply disappeared.

1) Naturally infected or vaccinated people can and usually do get re-infected. The infection is not important.
2) Previously naturally infected or vaccinated people usually have mild or asymptomatic disease with subsequent infections. (But not always e.g. Dengue).
3) The critical question is whether previous natural infection or vaccination reduces or prevents transmission onwards. In some cases it does - small pox, polio; in some cases not, TB or flu in pigs.

https://pubmed.ncbi.nlm.nih.gov/33268518/

 

[Dr.Sid]

https://coronavirus.jhu.edu/data/mortality

Country | Confirmed | Deaths | Case-Fatality | Deaths/100K pop.

United States | 42,853,724 | 687,084 | 1.6% | 209.32

I would just like to point out that these are actual recorded figures, as in, real things that actually happened, not some "estimate" of what might happen.

Real figures trump estimates.. every . single . time! Anyone who disagrees, take it up with Johns Hopkins University (contact details in the link).

And just to restate, for the benefit of those with reading or comprehension difficulties...

"Allowing the disease to spread so that your large proportion of the population become immune by getting the disease and surviving it. However, while this method might be financially cheaper, it would result in horrific toll in lives. The disease appears to have a morbidity rate in the US of between 1.4% and 1.6%. It has been estimated that natural herd immunity in the US could have cost between 4½ million and 5¼ million lives.

This literally means allowing it to spread unchecked. I was making the case for how herd immunity was arrived at in the past... no treatment, no vaccines, no respirators, treating it as if it was untreatable, when all they could do was make people as comfortable as they could, and they either survived or died.

Mixing CFR with IFR at this stage ? CFR is heavily affected by who gets tested, and in some countries it's estimated to be as much as 10 times lower than actual number of cases. It's pretty irrelevant number for estimates of how many more people can die.

I suggest looking at countries with lots of deaths (namely Czech and Hungary). Not everyone had Covid here .. but antibody studies suggest it's getting close. We were above 50% in March. There was one big wave after that and we have about 50% vaccinated.
And after all that we have give or take 0.3% of population dead. There is some undercount even for deaths, but it's not hundreds of %, as in case with CFR, and it can be compared to excess deaths. Which in case of Czech Republic shows the final bill is not higher than 0.4%.

For US that would be 984000 for 0.3%, 1312000 for 0.4% (With 700000 already gone). That's bad, but not 4 or 5 million bad.

Edit: OurWorlInData graph showing current death toll compared to population size, for selected countries.

https://ourworldindata.org/explorer...T~GBR~USA~JPN~ISR~ESP~GRC~TUR~FRA~ITA~SWE~AUS

 

[Bubba]

If case fatality rates can include healthy victims of crashes and drownings that had tested positive, where can one find numbers for deaths by covid ?

 

[Dr.Sid]

If case fatality rates can include healthy victims of crashes and drownings that had tested positive, where can one find numbers for deaths by covid ?

I doubt that would skew the numbers more than 1%. People diagnosed with COVID are supposed to be at home.

 

[The Atheist]

I would just like to point out that these are actual recorded figures, as in, real things that actually happened, not some "estimate" of what might happen.

It's always gratifying to see someone so wrong still trying to defend him/herself.

I gave you the scientific evidence and you completely ignored it to make the same mistake all over again. Nicely done.

Luckily, Dr Sid has explained it to you:

Mixing CFR with IFR at this stage ?

Yes, even as we approach two years of Covid, there are scaremongers around who want to paint the disease as deadlier than it actually is.

 

[Aridas]

If case fatality rates can include healthy victims of crashes and drownings that had tested positive, where can one find numbers for deaths by covid ?

For the most part, you can look at official current numbers if you want pretty much verified numbers. Alternately, the overwhelming portion of excess deaths is pretty certainly a direct result of death by covid, so that works as a decent indicator the true count. At the very beginning of the pandemic, there was a small issue that could be found with the inclusion of clear "with covid" deaths. As far as I recall, guidance changed not too long after, though, once there was more information to work with. The prior cases were reviewed and things like died of car crash but happened to test positive and homicide victim but tested positive were directly removed from the listed numbers. The total number of those cases was tiny overall, though. That didn't stop Republican propagandists from trying to make a huge deal of it, though, even after review and removal, in their efforts to sow doubt on the numbers for political gain.

I doubt that would skew the numbers more than 1%. People diagnosed with COVID are supposed to be at home.

Asymptomatic and pre-symptomatic cases wouldn't know to stay home and wouldn't necessarily have been tested before death. With that said, as I poked at above, active measures have been taken to remove that skew, tiny as it ended up being on review.

 

[marting]

Here's a pretty good analysis of general population immunity in the USA as of July 15. It's obviously higher now with Delta having made significant inroads in the last 6 weeks. In particular younger groups have had larger increases as Delta goes after the easier pickings. BTW, the under 18 group has had almost 3x the deaths of the worst flu season in the last 10 years but still under 500. And they, together with < 30 y/o have seen the largest increase in cases in the last month.

https://www.acpjournals.org/doi/10.7326/M21-2721

The mean overall population immunity was 62.0% (CrI, 58.4% to 66.4%). Adults aged 65 years or older were estimated to have the highest immunity level (77.2% [CrI, 76.2% to 78.6%]), and children younger than 12 years had the lowest immunity level (17.9% [CrI, 14.4% to 21.9%]).

 

[Dr.Sid]

Here's a pretty good analysis of general population immunity in the USA as of July 15. It's obviously higher now with Delta having made significant inroads in the last 6 weeks. In particular younger groups have had larger increases as Delta goes after the easier pickings. BTW, the under 18 group has had almost 3x the deaths of the worst flu season in the last 10 years but still under 500. And they, together with < 30 y/o have seen the largest increase in cases in the last month.

https://www.acpjournals.org/doi/10.7326/M21-2721

That's quite in line with my estimates based on IFR in 'bad' countries. 62% immunity would give 1129000 total potential (including 700000 already gone). This would be 0.34% of total population.

 

[lomiller]

Its not a mistake per se. Herd immunity can be a function of a natural process. How do you think populations of humans survived plagues and pandemics before we had vaccines?

Herd Immunity occurs when you get a sufficiently large proportion of the population that are immune to a disease, such that non-immune infected members of the remaining population have little no chance of spreading the disease to other non-immune members of the same population. This is why you may have heard people talking about how the vaccinated population can protect those who cannot, or will not take the jabs.

Herd Immunity can be achieved by...

1. A vaccination programme
The efficacious use of widespread vaccination to increase the immunity of as many people as possible. This is how smallpox and polio were eradicated. This way costs the smallest number of lives - if Covid had been properly managed in the US before the vaccines became available, and vaccinations had not been politicised by the political right, we would be talking about less than 20,000 to 30,000 deaths in the US, instead of almost 700,000.

2. Let the virus run wild
Allowing the disease to spread so that your large proportion of the population become immune by getting the disease and surviving it. However, while this method might be financially cheaper, it would result in horrific toll in lives. The disease appears to have a morbidity rate in the US of between 1.4% and 1.6%. It has been estimated that natural herd immunity in the US could have cost between 4½ million and 5¼ million lives.
.
.

R dropping below 1 can be achieved either by vaccination or by mass infection, but the interpretation of this point is completely different for the two cases. With vaccinations you can provide a significant degree of protection to the entire population by vaccinating enough people to bring R under 1. This protection is what scientists have general been referring to as herd immunity.

In the case of bringing R under 1 via mass infection you haven't achieved some from of protection. In the case of mass infection R=1 means you have seen ~1/2 of your final infection total. If R=1 when 50% of the population is infected it doesn't mean the other 50% are protected, it means you expect them to be infected because your final infection total will be ~ double your current total.

Herd immunity was always a concept specific to some form of intervention, primarily vaccination because it doesn't represent anything that could reasonably be called protection for the case of unabated mass infection.

 

[lomiller]

You are completely wrong, and it's the exact same nonsense that idiot Hendy has been peddling in NZ with his baloney "7000 will die at 70% vaccination". Gosh, I'd think people were panicking by getting the numbers so wrong if I didn't know nobody was panicking.

Seroprevalence testing has shown that only a fraction of cases ever get tested. The best estimate is that there have been 5-20 times more people infected than the numbers being tested and collated.

In terms of actual fatality rate, the best study to date shows:

The median infection fatality rate across all 51 locations was 0.27% (corrected 0.23%).

And would you know it, that is being borne out around the world, where infection rates plummet once mortality hits 0.2% of the population.

Whatever your reason is for overstating the case I have no idea, but it's woefully wrong.

I'm not convinced that seroprevalence data is suitable for this type of study. The problem is that false positives can easily outnumber real infections. The best estimates for IFR remain studies on known, closed populations like cruise ships. These have consistently reported IFR in the 0.5% - 1.0% depending on what age you adjust too. (closer to 1% for countries with older populations, closer to 0.5% for countries with younger populations.)

 

[lomiller]

If case fatality rates can include healthy victims of crashes and drownings that had tested positive, where can one find numbers for deaths by covid ?

Expected death numbers are probably the most comprehensive an inclusive. Even things like increase in suicide and decrease in car accidents due to pandemic restrictions would get included.

Expected deaths almost invariably show we are attributing fewer deaths to Covid that what it's actually causing. The reported number of Covid deaths is lower than the real number.

 

[The Atheist]

I'm not convinced that seroprevalence data is suitable for this type of study.

It's the best tool we have, and it's backed by real-world data, as noted by Dr Sid.

The problem is that false positives can easily outnumber real infections.

That's why the range is from 5-20 times. Right from the start it was known that a majority of cases did not get tested. All the estimates have been in that 5-20 range.

The best estimates for IFR remain studies on known, closed populations like cruise ships.

No, they have no relevance outside of cruise ships. The numbers are very limited, and at age 64, cruise ships have a much higher median age than general populations.

With that median age of 64, and an IFR of 0.5 - 1%, the cruise ship mortality rate translates into much lower rates in populations, exactly as shown in the studies quoted and as we're seeing in the wider pandemic.

The data on cruise ships is further overstated by all happening early in the pandemic, when treatments were still largely unknown.

Crikey, I really thought people would be up with the actual mortality rate by now - overstating it does nobody any favours.

 

[lomiller]

It's the best tool we have, and it's backed by real-world data, as noted by Dr Sid.

It really isn't. Like I said false positives are a real problem for this type of study.

No, they have no relevance outside of cruise ships. The numbers are very limited, and at age 64, cruise ships have a much higher median age than general populations.

That's why the numbers are age adjusted.

With that median age of 64, and an IFR of 0.5 - 1%,

Raw IFR numbers from cruise ships are much higher than that. Upwards of 2% - 4%. the 0.5 - 1% are adjusted to the typical age of a population. Eg 1 prominent study found that adjusted to the age profile of China the ~3% IFR corresponded to an expected IFR of 0.6% for China. This number would have been higher had they mapped it to an older country like the US.

 

[Aridas]

Expected death numbers are probably the most comprehensive an inclusive. Even things like increase in suicide and decrease in car accidents due to pandemic restrictions would get included.

Expected deaths almost invariably show we are attributing fewer deaths to Covid that what it's actually causing. The reported number of Covid deaths is lower than the real number.

Two things. First, it looks like you're talking about excess deaths, not expected deaths, though the two are certainly related. Excess deaths would be the one that actually reflects the covid deaths.

Second, it's worth adding additional information to that point. While increases in suicides could easily be reflected in excess deaths, it looks suicides actually dropped, which means that other causes were even more pronounced than would have otherwise been expected, which, in practice, means that even more of the excess deaths can fairly safely be attributed directly to covid, with the potential of exceeding the excess death count.

 

[The Atheist]

It really isn't. Like I said false positives are a real problem for this type of study.

You've lost the plot, mate.

The seroprevalence studies have been confirmed by actual data after 20 months of the disease. They're further confirmed by the certain knowledge that vast numbers of cases were never counted.

You're trying to create a scenario that doesn't fit any of the known data about the disease.

Why are you trying to overstate the mortality?