Get Vaccinated Against the Covid Delta Variant

In summary: Delta variant, a Coronavirus strain first detected in India, is now officially designated as a variant of concern by the Centers for Disease Control and Prevention (CDC). This designation is given to variants shown to be more transmissible than the original strain, which can cause more severe disease and potentially reduce the effectiveness of treatments or vaccines. As a result, the CDC is urging people who have not yet been vaccinated against COVID-19 to do so now. The Delta variant looks like it might be up to 60 percent more infectious than other variants of COVID-19, and as a result, the CDC is concerned that it could lead to more widespread and severe infections. However, both vaccine versions currently available are still effective against Delta-infect
  • #211
CarlB said:
Re: "Please furnish/discuss only CURRENT data. Thank you."

Some of the documentation for the website is from 2020 but the data is as of July 21, 2021. You can use their tool to extract various time series, for instance:View attachment 286726
On the website, I ordered the data by month but this silly laptop doesn't actually take a "screenshot" when you do "screenshot" so it reorders the time confusingly to the default. Your mileage may vary.
Thank you, my apologies, for not noticing it would pull newer data.
 
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  • #212
Evo said:
@CarlB

Aren't Blacks and Hispanics usually religious? But without religion, (let's drop religion, my bad) what is the percentage vaccinated would be the question.Actually it makes a lot of sense. Urban areas are more crowded, have more activities where large numbers of people interact, rural areas wouldn't, so it would be expected that urban areas would have higher rates due to contacts.
Blacks and Hispanics have higher rates of obesity. That is associated with hypertension and diabetis. So that could also explain the Covid percentiles. Obesity in these groups is from sugar and starch diets. While the immune system requires proteins. https://www.cdc.gov/obesity/data/adult.html
 
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  • #214
And then there is vitamin D, another correlation.

from: https://pubmed.ncbi.nlm.nih.gov/33146028/

Vitamin D deficiency aggravates COVID-19: systematic review and meta-analysis​


from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6075634/
Race was identified as a significant risk factor, with African-American adults having the highest prevalence rate of vitamin D deficiency (82.1%, 95% CI, 76.5%-86.5%) followed by Hispanic adults (62.9%; 95% CI, 53.2%-71.7%) [3]. Additional risk factors for vitamin D deficiency that were identified included obesity, lack of college education, and lack of daily milk consumption [3].

Cheers,
Tom
 
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  • #215
Technical briefing up to July 9th. https://assets.publishing.service.g...t_data/file/1005517/Technical_Briefing_19.pdf

DELTA dominant in the UK, 99% of cases sequenced, page 21
Variants of concern and variants under investigation data (VOC, VUI) page summary page 13
Page 18-19 is cases that end up in A&E, overnight stay, admitted as inpatients, deaths over and under 50s, vaccinated and unvaccinated.

Deaths from vaccinated has now taken over those vaccinated.
As explained previously the numbers vaccinated exceed those unvaccinated by a factor of around 20.
The number of deaths of vaccinated exceed those unvaccinated by a factor of 1.35 all cases.
The number of deaths of under 50s unvaccinated exceeds those vaccinated by a factor of about 9 although the numbers are small relatively speaking 34 and 4 respectively.
 
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  • #216
Evo said:
This is a reason a large portion of the states in areas where the Covid Delta cases are rising fastest, these states are highly Evangelical.
Quote from the Yahoo news article:
"I am not playing these Democrat games up in this church," he added.
continued...

https://www.yahoo.com/news/evangelical-pastor-demands-churchgoers-ditch-101435205.html
Obviously, vaccines have no political leanings. But for those who subscribe to that logic, the mRNA vaccines are very Republican. They were developed under the Trump administration and Trump himself was vaccinated with one.
 
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  • #217
Tell them that!
 
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  • #218
.Scott said:
Obviously, vaccines have no political leanings. But for those who subscribe to that logic, the mRNA vaccines are very Republican. They were developed under the Trump administration and Trump himself was vaccinated with one.
mRNA vaccine technology has been under development for decades (some of the key early work was published in the mid 2000s, see https://www.physicsforums.com/threads/messenger-rna-mrna-not-just-for-coronavirus-vaccines.1000153/). While Moderna received funding from the US to help develop and test their SARS-CoV-2 vaccine, Pfizer (whose vaccine accounts for the most vaccinations in the US) did not receive funding from the US or Project Warp Speed to develop, test or manufacture the vaccine, instead most of that funding came from Germany (https://www.bloomberg.com/news/arti...ine-s-funding-came-from-berlin-not-washington).

However, if crediting the vaccines to the Trump administration helps get more people vaccinated, then perhaps that's not a bad thing overall.
 
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  • #219
In another post I provided several reasons to believe that the Delta variant doesn't just "spread more easily" - it seems to spread a lot more easily.

But since I am detecting some hesitancy to accept that the Delta variant could really be that bad and to further demonstrate what "that bad" really means, let me start with a comparison...

The diameter of the SARS-C0V-2 virus particle is in the range of 50 to 160nm. From that same source, respiratory droplets are typically 5-10µm - larger by 2 orders of magnitude. But respiratory droplets do not last very long. They are, after all, mostly water - and the relative humidity is seldom high enough to keep them from quickly drying up - releasing their viral load. This is why I am not entirely comfortable with the term "aerosol". I have always used a term I was given in high school chemistry: "colloidal dispersion" - such as smoke.

In comparison, the diameter of MeV (the Measles virus) using the same measurement methods is in the the range of 300 to 1000nm for the "purified virions" with nucleocapsids 21nm diameter x 1254nm length. I don't know if these nucleocapsins separate from each other while suspended in air, but even if they do, one would be about the same volume as a 94nm sphere.
So when it comes to remaining lofted in the air and penetrating deep into the respiratory system, it's not clear which of these would have the advantage - they should be in the same league. But since MeV is a more experienced and practiced player, we might suspect that it has had more opportunity to perfect its art.

So if you want to revel in awe and admiration, break yourself away from the Tokyo Olympics to consider this - from the CDC:
Measles is a highly contagious virus that lives in the nose and throat mucus of an infected person. It can spread to others through coughing and sneezing.

If other people breathe the contaminated air or touch the infected surface, then touch their eyes, noses, or mouths, they can become infected.
...
Measles is so contagious that if one person has it, up to 90% of the people close to that person who are not immune will also become infected.
...
Measles virus can live for up to two hours in an airspace after an infected person leaves an area.
I'm not convinced that SARS-CoV-2, Delta has fully mastered the "infected surface" event. So far I haven't even seen anecdotal evidence for a severe fomite-induced COVID-19 case. But give it time - I expect to see it return for the 2024 Olympics (Paris).
On the other hand, I don't see any reason why it shouldn't do very well in that 2-hour stagnant air event.

And of course, COVID-19 has introduced the "singing" maneuver into the sport - adding much-needed variation to the standard "coughing and sneezing".

Early indications are that it should also excel in the Vaccine Breakthrough event - spreading deep through vaccinated territory before finding those precious islands of the unvaccinated.

If the Delta variant is as contagious as it promises to be, we need to review our basic strategies.
I do not doubt that vaccinations, wearing masks, and socially distancing can slow the spread of the Delta variant. But it also appears that none of these things can stop it from spreading through most US communities. There may still be reasons to slow it down, but buying time for vaccine development and distribution isn't as important as it use to be - as most of the unvaccinated in the US seem to be determined to stay that way. For most places in the US, the availability of ICU space and other medical resources has not been challenged for months.

Perhaps what we should be attempting to do is to "pace" the spread.
 
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  • #220

CDC mask decision followed stunning findings from Cape Cod beach outbreak​

https://abcnews.go.com/Politics/cdc-mask-decision-stunning-findings-cape-cod-beach/story?id=79148102
As of Thursday, 882 people were tied to the Provincetown outbreak. Among those living in Massachusetts, 74% of them were fully immunized, yet officials said the vast majority were also reporting symptoms. Seven people were reported hospitalized.

Walensky hinted that the biggest driver was new unpublished research on a person's "viral load" -- the amount of virus in a person's nasal passages -- being considerably high even after being vaccinated with a U.S.-approved vaccine.

"What we've learned … is that when we examine the rare or breakthrough infections and we look at the amount of virus in those people, it is pretty similar to the amount of virus in unvaccinated people," she said.
Apparently, more details to be released tomorrow.Accroding to the ABC article, the US is averaging 57,000 new COVID-19 cases per day due to delta variant
 
  • #221
Ygggdrasil said:
... While Moderna received funding from the US to help develop and test their SARS-CoV-2 vaccine, Pfizer (whose vaccine accounts for the most vaccinations in the US) did not receive funding from the US or Project Warp Speed to develop, test or manufacture the vaccine, instead most of that funding came from Germany (https://www.bloomberg.com/news/arti...ine-s-funding-came-from-berlin-not-washington).
Not the story in context. Pfizer actually WAS a part of Project Warp Speed. And they eventually admitted it.
 
  • #222
pinball1970 said:
https://assets.publishing.service.g...t_data/file/1005517/Technical_Briefing_19.pdf

Deaths from vaccinated has now taken over those vaccinated.
As explained previously the numbers vaccinated exceed those unvaccinated by a factor of around 20.
The number of deaths of vaccinated exceed those unvaccinated by a factor of 1.35 all cases.
I'm really struggling on these three sentences. Can you clarify ? Looked at the paper a few times , cannot see it.
 
  • #223
Fiji desperately needs to go into lockdown. Thank goodness I got out of there when I did last year.
 
  • #224
chemisttree said:
Not the story in context. Pfizer actually WAS a part of Project Warp Speed. And they eventually admitted it.
The tweet is consistent with what the article stated. Pfizer did not use US funding for research or development of the vaccine. Funds provided by OWS were for a purchase agreement.
 
  • #225
There's considerable data that non vaccinated people are doing worse with the Delta variant than vaccinated. They're saying that viral loads are very high. So I was wondering when this would show up in the "excess mortality" graphs. These graphs are cool because, like murder, the statistics for "died" are pretty good, as compared to "died of Covid" which depends on medical tests, definitions, judgement, etc. The excess mortality graphs are here: https://www.cdc.gov/nchs/nvss/vsrr/covid19/excess_deaths.htm

And I read that Blacks in particular have very high non vaccination rates. This is mostly from a lack of trust of the government, apparently. This means that Blacks and Hispanics are going to be over represented in the numbers of "unvaccinated and died of Covid" numbers, which might imply that the statistics we're seeing that allegedly describe the protective activity of the vaccine are partially instead the protective activity of being White non Hispanic. But I don't know how to unconfound these contributions. Here's the interesting US graphical data for deaths by week and race:
2021BW.png


A partial way of looking at this is to compare with the 2020 data which is mostly before vaccinations. And sure enough, Non-Hispanic Whites did well then too. Note that the rural areas (which in the US are more white than the urban) were hit more in the 2nd peak, while the big urban areas got nailed bad in the first 2020 peak:
2020BW.png

Presently the Delta variant is hitting urban areas in the US much harder than rural so that would accent the Black part of the graphs more than the white. As of July 1 the vaccination rates are about White: 66%, Black: 51% and Hispanic: 63% with White vaccination having occurred earlier with the other groups catching up. See https://scopeblog.stanford.edu/2021...disparities-in-covid-19-vaccination-coverage/ and https://www.kff.org/coronavirus-cov...data-on-covid-19-vaccinations-race-ethnicity/

Those vaccination rates aren't hugely different, compared to the differences in excess deaths. So I don't think that race can account for much of the difference in Delta death rates due to vaccination status. Especially since it's Hispanics who have the worst outcomes but their vaccination status is closest to Non-Hispanic Whites. Also note that American Indians have high death rates and that Spain had some of the worst Covid problems in Europe, IIRC.

The reason I got interested in this is because various trustworthy (?) sources are saying that the Delta variant gets viral loads in vaccinated individuals that are comparable to viral loads in the unvaccinated. Naively, I would suppose that should mean a lot of deaths. And deaths are a delayed indicator so I should probably wait another month and look again.
 
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  • #226
morrobay said:
I'm really struggling on these three sentences. Can you clarify ? Looked at the paper a few times , cannot see it.
One of the main changes is deaths vaccinated versus unvaccinated.

The number of deaths are 224 vaccinated two doses, verses 165 unvaccinated, that’s a factor of 1.35 difference.

I expressed it this way because of a misconception reading the data from a previous briefing that showed the number of deaths in the vaccinated verses vaccinated groups was the same.

This indicated the vaccine made no difference (to me anyway until it was explained))

However the total number of those vaccinated groups was much higher than those not vaccinated in most of the adult groups, high 90%s. (see graph and link below)

So the total vaccinated groups exceeds the non- vaccinated by a factor of about 19. (for the older groups at least)

The under 50s deaths specifically are the other way round, not as many vaccinated (high 50s-80s) but far fewer deaths 4 verses 34, a factor of about 9.

So three - four times more people but 9 times higher deaths.

The graph is in the link below where you can see the split of % in age groups vaccinated

https://www.bbc.co.uk/news/health-55274833

1627633793231.png
 
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  • #227
The Hill: CDC internal memo calls delta variant as contagious as chickenpox: report
https://thehill.com/policy/healthca...lls-delta-variant-as-contagious-as-chickenpox
An internal memo from the Centers for Disease Control and Prevention (CDC) reportedly says that the highly transmissible delta variant may cause worse illnesses than other versions of COVID-19 and is more contagious than other leading viruses.

The document, first reported by The Washington Post, reportedly urges health officials to “acknowledge the war has changed” and cites still-unpublished data showing that individuals vaccinated against COVID-19 may transmit the delta variant just as easily as unvaccinated groups.
https://www.washingtonpost.com/health/2021/07/29/cdc-mask-guidance/

According to the Post, the internal memo is a slide presentation shared within the CDC and obtained by the news outlet and in part mentions “communication challenges” regarding viruses in vaccine people, including concerns from local health department about whether vaccines are effective against the delta variant and a “public convinced vaccines no longer work/booster doses needed."

The New York Times, which also obtained a copy of the document, shows that the delta variant could be more infectious than the viruses that cause MERS, SARS, Ebola, the common cold, the seasonal flu and smallpox and is just as contagious as chickenpox.
https://www.nytimes.com/2021/07/30/health/covid-cdc-delta-masks.html

The Hill has reached out to the CDC for additional information.

In the Washington Post article,
The presentation highlights the daunting task the CDC faces. It must continue to emphasize the proven efficacy of the vaccines at preventing severe illness and death while acknowledging milder breakthrough infections may not be so rare after all, and that vaccinated individuals are transmitting the virus. The agency must move the goal posts of success in full public view.The CDC declined to comment.
 
  • #228
First, at this point, I hope it's clear to everyone that CDC pronouncements are intended to influence the desired behavior more than being truthful. Whose benefit are the masks for? Not for fully vaccinated individuals - they are fully vaccinated. For the unvaccinated? One could argue that a) they have made their choice, but in any event, the risk of vaccinated --> unvaccinated transmission is microscopic compared to unvaccinated --> unvaccinated.

No, the point is to keep people from "cheating".

Second, look at Ontario. Mostly delta, and has been for a while. The Canadian press is fretting that the rate has moved up to 1.1 cases/day per 100K from 1.0. Over about a month. That's down a factor of ~25 from the peak. You want to know what delta looks like in a 70% vaccinated population? There you go.
 
  • #229
Vanadium 50 said:
the risk of vaccinated --> unvaccinated transmission is microscopic compared to unvaccinated --> unvaccinated.
This now looks to be inaccurate. Washington Post obtained unpublished internal CDC docs suggesting delta variant transmissibility is comparable between vaccinated vs. unvaccinated. The viral loads seem to be similar in both cases, but the vaccinated folks just aren’t getting as sick. (Slides 17ff)
https://context-cdn.washingtonpost..../7335c3ab-06ee-4121-aaff-a11904e68462.#page=1
 
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  • #230
Vanadium 50 said:
First, at this point, I hope it's clear to everyone that CDC pronouncements are intended to influence the desired behavior more than being truthful.
And so are many of the CDC announcements ... and it is certainly harming trust in the vaccines.
They need to stop worrying about how their statements will be taken .. and within reasonable public safety limits, let people make their own mistakes.
 
  • #231
Re: "The viral loads seem to be similar in both cases, but the vaccinated folks just aren’t getting as sick."

I'd like to hear a medical explanation for how this could possibly happen. If anything, I would think that having a high viral load and not "getting sick" would be an extremely bad sign. Something is very very wrong. It implies that the immune system is failing to do what it's supposed to do.

I don't have an explanation for this. The only thing that comes to mind is that it sounds suspiciously like the kind of thing a vaccine salesman would say rather than a doctor. If you have ideas that can calm me I'd like to hear them. Something other than "trust the authorities" would be appreciated.

One thing that immediately comes to mind is Antibody Dependent Enhancement. This is why a lot of Coronavirus vaccines never hit the market. ADE ruins the long term tests. With the experimental vaccines we're currently using, this was supposed to be eliminated theoretically by being careful about the vaccine targets (so as to avoid "non neutralizing" antibody production).

When a neutralizing antibody attaches to a virus it prevents the virus from entering cells. A non neutralizing antibody just attaches to the virus. The non neutralizing antibodies are useful in that they attract the attention of the immune system and some cells come along and eat the virus. But sometimes this process of eating gets messed up and the virus infects the immune cell. In this case, the antibody helps the virus replicate and this effect is called ADE. There are other ADE pathways.

Anyway with this ADE pathway, an effect is that the virus harms part of the immune system. Maybe that's why a victim can have a high viral load and not feel sick; I do not know, I will try to read more on the subject.

This problem was predicted for the Covid vaccines. This article was published in February, which I suppose is well before Delta variant became a big deal:

"Development of vaccines to severe acute respiratory syndrome (SARS), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and other Coronavirus has been difficult to create due to vaccine induced enhanced disease responses in animal models."
"While expanded trophism[sic] of SARS-CoV-2 represents a possible ADE risk in the subset of COVID-19 patients with disease progression beyond the mild disease stage."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7943455/

They've written "trophism" in the conclusion, which is a biological term relating to the food chain. Obviously they meant "tropism" which in the context of viruses, is about viral response to evolutionary pressure, that is, the emergence of the delta variant in response to the evolutionary pressure of vaccines. In other words, the evolution to the Delta variant represents a possible ADE risk.
 
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  • #232
CarlB said:
Re: "The viral loads seem to be similar in both cases, but the vaccinated folks just aren’t getting as sick."

I'd like to hear a medical explanation for how this could possibly happen. If anything, I would think that having a high viral load and not "getting sick" would be an extremely bad sign. Something is very very wrong. It implies that the immune system is failing to do what it's supposed to do.

I don't have an explanation for this. The only thing that comes to mind is that it sounds suspiciously like the kind of thing a vaccine salesman would say rather than a doctor. If you have ideas that can calm me I'd like to hear them. Something other than "trust the authorities" would be appreciated.

One thing that immediately comes to mind is Antibody Dependent Enhancement. This is why a lot of Coronavirus vaccines never hit the market. ADE ruins the long term tests. With the experimental vaccines we're currently using, this was supposed to be eliminated theoretically by being careful about the vaccine targets (so as to avoid "non neutralizing" antibody production).

When a neutralizing antibody attaches to a virus it prevents the virus from entering cells. A non neutralizing antibody just attaches to the virus. The non neutralizing antibodies are useful in that they attract the attention of the immune system and some cells come along and eat the virus. But sometimes this process of eating gets messed up and the virus infects the immune cell. In this case, the antibody helps the virus replicate and this effect is called ADE. There are other ADE pathways.

Anyway with this ADE pathway, an effect is that the virus harms part of the immune system. Maybe that's why a victim can have a high viral load and not feel sick; I do not know, I will try to read more on the subject.

This problem was predicted for the Covid vaccines. This article was published in February, which I suppose is well before Delta variant became a big deal:

"Development of vaccines to severe acute respiratory syndrome (SARS), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and other Coronavirus has been difficult to create due to vaccine induced enhanced disease responses in animal models."
"While expanded trophism[sic] of SARS-CoV-2 represents a possible ADE risk in the subset of COVID-19 patients with disease progression beyond the mild disease stage."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7943455/

They've written "trophism" in the conclusion, which is a biological term relating to the food chain. Obviously they meant "tropism" which in the context of viruses, is about viral response to evolutionary pressure, that is, the emergence of the delta variant in response to the evolutionary pressure of vaccines. In other words, the evolution to the Delta variant represents a possible ADE risk.
A little more context from CNN (https://www.cnn.com/2021/07/30/health/breakthrough-infection-masks-cdc-provincetown-study/index.html):

But even with similar viral loads, it's not a foregone conclusion that vaccinated people are necessarily as contagious as unvaccinated people.

"This is intriguing data, it's important, but I'm not positive that you're equally as infectious if you're vaccinated," said Dr. Monica Gandhi, an infectious disease specialist at University of California, San Francisco, who was not involved in the research.

Gandhi said there are multiple parts to the immune system -- including antibodies and T cells -- that raise important questions around using viral load, which is measured by PCR tests, as a proxy for how contagious someone is.

The new report says that "microbiological studies are required to confirm these findings" of similar viral loads among breakthrough infections. It also notes that "asymptomatic breakthrough infections might be underrepresented" because they are less likely to be detected.
Viral load also depends on how far along you are in the course of infection. It could be that viral loads increase steeply, but that vaccinated people's adaptive immune system can clear it and prevent symptoms from appearing more efficiently than unvaccinated people, who might have a stronger systemic immune response (the general inflammation that makes you feel like garbage).

Also mentioned was that, of the 75% of people at the Massachusetts superspreader event who were vaccinated and later became infected, 79% exhibited symptoms (I'm not sure how severe those symptoms were). At any rate, several studies show that the vaccinated immune system is able to manage infection with the delta variant quite well and that breakthrough events are unlikely and often quite mild.

I think someone else (@atty or @Ygggdrasil maybe) has posted on ADE studies with SARS-CoV-2. Maybe I'm misremembering.
 
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  • #233
CarlB said:
Re: "The viral loads seem to be similar in both cases, but the vaccinated folks just aren’t getting as sick."

I'd like to hear a medical explanation for how this could possibly happen. If anything, I would think that having a high viral load and not "getting sick" would be an extremely bad sign. Something is very very wrong. It implies that the immune system is failing to do what it's supposed to do.

Here's an excerpt for an article on the subject that may partially answer the question:
Although lung infection is a major component of severe COVID-19 (and relatively slow), URT infection is important for transmission. Notably, a vaccine that can prevent severe disease, or even most URT symptomatic diseases, would not necessarily prevent transmission of virus. For example, the current pertussis vaccine prevents clinical disease but not infection, and probably not transmission (Warfel et al., 2014), and much SARS-CoV-2 transmission occurs early, during the pre-symptomatic phase (He et al., 2020). Several non-human primate COVID-19 vaccine studies are consistent with the possibility of COVDI-19 vaccines preventing severe disease in humans but possibly not preventing URT infection (Corbett et al., 2020; van Doremalen et al., 2020; Gao et al., 2020; Guebre-Xabier et al., 2020; Mercado et al., 2020; Tostanoski et al., 2020; Vogel et al., 2020; Yu et al., 2020). It is plausible that SARS-CoV-2 infection may elicit better protective immunity in the URT than any of the major current COVID-19 vaccine candidates, because infection occurs at that site and is therefore more likely to elicit tissue-resident memory. Tissue-resident T cells were relevant for protective immunity in a SARS mouse model (Zhao et al., 2016) and B. pertussis infection versus pertussis immunization (Kapil and Merkel, 2019), but more needs to be learned about local immunity to SARS-CoV-2. A number of human vaccines against respiratory pathogens do not depend on local T cell memory, or are very unlikely to elicit URT T cell memory, such as measles, smallpox, and flu vaccines, as well as RSV vaccines in clinical trials.​
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7803150/

First, we have seen examples of vaccines that do prevent symptomatic disease without preventing transmission (e.g. the pertussis vaccine), and this is not due to something being very very wrong. Second, infection in the upper respiratory tract (URT) allows transmission of the virus (while often causing asymptomatic disease in the early stages) whereas infection in the lung and other parts of the body are associated with severe disease. If vaccination (though injection in the arm) does not elicit good tissue-resident immunity in the upper respiratory tract, then the vaccine might not prevent URT infection, asymptomatic disease and transmission (esp. if the virus has mutated to evade antibody-based immunity or antibody-based immunity has waned over time). However, because memory B- and T- cells are present in vaccinated individuals, the URT infection will quickly trigger an adaptive immune response that can stop the spread of the virus to the lungs and other parts of the body to prevent severe disease (plenty of studies associate delayed activation of B- and T-cell based immunity with severe disease, so the quicker the body can mount a B- and T-cell response to an infection, the better the prognosis).

CarlB said:
One thing that immediately comes to mind is Antibody Dependent Enhancement. This is why a lot of Coronavirus vaccines never hit the market. ADE ruins the long term tests. With the experimental vaccines we're currently using, this was supposed to be eliminated theoretically by being careful about the vaccine targets (so as to avoid "non neutralizing" antibody production).

When a neutralizing antibody attaches to a virus it prevents the virus from entering cells. A non neutralizing antibody just attaches to the virus. The non neutralizing antibodies are useful in that they attract the attention of the immune system and some cells come along and eat the virus. But sometimes this process of eating gets messed up and the virus infects the immune cell. In this case, the antibody helps the virus replicate and this effect is called ADE. There are other ADE pathways.

Anyway with this ADE pathway, an effect is that the virus harms part of the immune system. Maybe that's why a victim can have a high viral load and not feel sick; I do not know, I will try to read more on the subject.

This problem was predicted for the Covid vaccines. This article was published in February, which I suppose is well before Delta variant became a big deal:

"Development of vaccines to severe acute respiratory syndrome (SARS), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and other Coronavirus has been difficult to create due to vaccine induced enhanced disease responses in animal models."
"While expanded trophism[sic] of SARS-CoV-2 represents a possible ADE risk in the subset of COVID-19 patients with disease progression beyond the mild disease stage."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7943455/

They've written "trophism" in the conclusion, which is a biological term relating to the food chain. Obviously they meant "tropism" which in the context of viruses, is about viral response to evolutionary pressure, that is, the emergence of the delta variant in response to the evolutionary pressure of vaccines. In other words, the evolution to the Delta variant represents a possible ADE risk.

Many studies have looked for signs of ADE, but none have found any, even with the variants. To quote an article on the subject:
So here’s the short version: no sign of ADE during the preclinical animal studies. No sign during the human clinical trials. No sign during the initial vaccine rollouts into the population. And (so far) no sign of ADE even with the variant strains in different parts of the world. We have things to worry about in this pandemic, but as far as I can tell today, antibody-dependent enhancement does not seem to be one of them. I understand why people would worry about it, and want to avoid it. But if you’re coming across reports that say that it’s a real problem right now and that you should avoid getting vaccinated because of it, well, I just don’t see it. Some of that is well-intentioned caution, and some of it is probably flat-out anti-vaccine scaremongering.​
https://blogs.sciencemag.org/pipeli...dent-enhancement-and-the-coronavirus-vaccines (the full article is a good read if one is interested on the topic)

ADE could still be a risk with newer variants, but there are plenty of researchers looking at many sources of data to compare how vulnerable vaccinated and unvaccinated populations are to the new variants, so we would likely be able to see signs of ADE if a new variant that promotes ADE emerges (but so far we have not observed such an event occur).
 
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  • #234
Astronuc said:
The Hill: CDC internal memo calls delta variant as contagious as chickenpox: report
https://thehill.com/policy/healthca...lls-delta-variant-as-contagious-as-chickenpox
Although the slides contain that line, it is next to data showing a wide range of uncertainty, with the overlap with chickenpox at the upper end of that range. I can't find the slides now (they were linked in some news article I googled yesterday), but IIRC the lower end was at around 5.
 
  • #235
atyy said:
IIRC the lower end was at around 5.
R0 (5,9) or 7 +/- 2 and fatality rate was ~0.15 to 1.5%. Large box meaning large uncertainty.
 

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  • #236
Vanadium 50 said:
One could argue that a) they have made their choice, but in any event, the risk of vaccinated --> unvaccinated transmission is microscopic compared to unvaccinated --> unvaccinated.

TeethWhitener said:
This now looks to be inaccurate. Washington Post obtained unpublished internal CDC docs suggesting delta variant transmissibility is comparable between vaccinated vs. unvaccinated. The viral loads seem to be similar in both cases, but the vaccinated folks just aren’t getting as sick. (Slides 17ff)
https://context-cdn.washingtonpost.../7335c3ab-06ee-4121-aaff-a11904e68462.#page=1
It seems to be based on on the cycle threshold (CT) values reported in https://www.cdc.gov/mmwr/volumes/70/wr/mm7031e2.htm. It's not fully confirmed, as CT values can be affected by things other than viral load, but it's reasonable to take it as strongly suggestive: "Finally, Ct values obtained with SARS-CoV-2 qualitative RT-PCR diagnostic tests might provide a crude correlation to the amount of virus present in a sample and can also be affected by factors other than viral load.††† Although the assay used in this investigation was not validated to provide quantitative results, there was no significant difference between the Ct values of samples collected from breakthrough cases and the other cases. This might mean that the viral load of vaccinated and unvaccinated persons infected with SARS-CoV-2 is also similar. However, microbiological studies are required to confirm these findings."
 
  • #237
Maybe, that's the solution:
JERUSALEM, July 29 (Reuters) - Israel will begin offering a third shot of the Pfizer (PFE.N)/BioNTech COVID-19 vaccine to people aged over 60, a world first in efforts to slow the spread of the highly contagious Delta variant.

Prime Minister Naftali Bennett, launching the campaign, said President Isaac Herzog would be the first to receive the booster, on Friday.
Source:
https://www.reuters.com/world/middl...ople-over-60-israeli-news-reports-2021-07-29/
 
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  • #238
Sagittarius A-Star said:
But maybe the problems in Israel and the US are different.

In Israel, the population is highly vaccinated, and the third dose will mainly be to try to raise protection against severe disease from the low 90s to the high 90s in a vulnerable population - the same idea as in the UK's third dose for seniors and the CDC's consideration of whether to recommend a third dose to immune-compromised people. Neither the UK nor Israel are (yet?) having problems with hospital capacity due to Delta.

In the US, however, some parts of the population are not highly vaccinated, and because Delta is highly transmissible, they are causing problems with hospital capacity in some places. Here what is needed is not so much a third jab, as first jabs.
https://www.wmcactionnews5.com/2021/07/29/surge-covid-19-cases-arkansas-leads-shortage-icu-beds/
https://apnews.com/article/health-coronavirus-pandemic-utah-0d9b27135f5e7f0f14a174e42aca3fb1
 
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  • #239
atyy said:
But maybe the problems in Israel and the US are different.

In Israel, the population is highly vaccinated, and the third dose will mainly be to try to raise protection against severe disease from the low 90s to the high 90s in a vulnerable population - the same idea as in the UK's third dose for seniors and the CDC's consideration of whether to recommend a third dose to immune-compromised people. Neither the UK nor Israel are (yet?) having problems with hospital capacity due to Delta.

In the US, however, some parts of the population are not highly vaccinated, and because Delta is highly transmissible, they are causing problems with hospital capacity in some places. Here what is needed is not so much a third jab, as first jabs.
https://www.wmcactionnews5.com/2021/07/29/surge-covid-19-cases-arkansas-leads-shortage-icu-beds/
https://apnews.com/article/health-coronavirus-pandemic-utah-0d9b27135f5e7f0f14a174e42aca3fb1
9 million population in Israel, 66 million UK. Not small numbers but not the 320 million in the US with 9 (edit) time zones and vastly different infrastructure and demographics dwarfs the logistics there.

Outlook is good though? We (UK) are yo-yoing down. Deaths hit over 100 last week but we have to expect that from 54,000 cases at the high.
 
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  • #240
I do not believe the R = 13 number.

Reason 1: It comes from the CDC. As I said above, the CDC pronouncements are clearly intended to encourage the desired behavior rather than being strictly factual.

Reason 2: The slide deck in question is (see the first page past the cover) about messaging.

Reason 3: There is not a single study linked to that number. The only reference is to the NYT. Of course the media is eating it up, because it is. as they say. "too good to check".

Reason 4: I know that we should believe whatever the CDC says (because Science!) and not look at the data (which is anti-Science) but I can't help but look at the data. I also hate to keep returning to Ontario, but they do the best job of presenting data.

The infectious period is 8-10 days. Call it 9. Delta was ~5% of the cases on May 10. 78 days is 8.7 infectious periods and 138.7= 5 billion. That's crazy high. Put another way, from a single infected individual in under two months the entire province can be infected in under 2 months.

Now, I hear you say, "everybody knows that exponentials cannot go on forever". But if we're past the point where exponentials make sense, and R is no longer useful, why is the CDC using it? "Too good to check". What is the value in reporting not what R actually is, but what it would be in some counterfactual world?

And what is R? Let's ask the Canadians.

1627743632575.png


There's that pesky data again.

Let's look at another country in the news, the Netherlands. They had a delta spike:
1627744089501.png


And you can see that R is in fact higher - the leading edge is sharper.
OK, so how many people died?

1627744176816.png

There you go.

This also illustrates the problem with the focus on "cases", which is really defined as "anyone who tests positive, irrespective of the degree of symptom severity, or indeed, if there are any symptoms at all". Covid didn't get 150x less dangerous in a year. Vaccines made it less dangerous, but not 150x (half the population is fully vaccinated) less dangerous. You are seeing the results of more screening.

Is Delta more dangerous than other strains? Looks like it. Is it so much more dangerous that new drastic steps are necessary? That seems to be what the CDC (Science!) is telling us. but not what the data (anti-Science) is.
 
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  • #241
I'm feeling a little better about ADE, thanks.
 
  • #242
Vanadium 50 said:
I do not believe the R = 13 number.
Where did you get the R = 13 number? In the CDC documents cited in post #229, it looks like the range is 5-9. Given an initial estimate of R0 for the ancestral SARS-CoV-2 strain of ~ 3, these figures are consistent with published, peer-reviewed studies that examine data of the spread of various variants and estimate that the Delta variant spreads about twice as effectively as the original variant (e.g. https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2021.26.24.2100509).

Vanadium 50 said:
Reason 4: I know that we should believe whatever the CDC says (because Science!) and not look at the data (which is anti-Science) but I can't help but look at the data. I also hate to keep returning to Ontario, but they do the best job of presenting data.

The infectious period is 8-10 days. Call it 9. Delta was ~5% of the cases on May 10. 78 days is 8.7 infectious periods and 138.7= 5 billion. That's crazy high. Put another way, from a single infected individual in under two months the entire province can be infected in under 2 months.

Now, I hear you say, "everybody knows that exponentials cannot go on forever". But if we're past the point where exponentials make sense, and R is no longer useful, why is the CDC using it? "Too good to check". What is the value in reporting not what R actually is, but what it would be in some counterfactual world?

And what is R? Let's ask the Canadians.

View attachment 286920
Note that Ontario enforces universal masking requirements, so the data reflects vaccination + masking. The data cannot be used to conclude that vaccination w/o masking is sufficient to contain the spread of the Delta variant.

Vanadium 50 said:
Let's look at another country in the news, the Netherlands. They had a delta spike:
View attachment 286921

And you can see that R is in fact higher - the leading edge is sharper.
OK, so how many people died?

View attachment 286922
There you go.

This also illustrates the problem with the focus on "cases", which is really defined as "anyone who tests positive, irrespective of the degree of symptom severity, or indeed, if there are any symptoms at all. Covid didn't get 150x less dangerous in a year. Vaccines made it less dangerous, but not 150x (half the population is fully vaccinated0 less dangerous. You are seeing the results of more screening.

Here, I agree with you. Consistent with the clinical trial data and many real world observational studies, vaccination greatly reduces the risk of severe disease, hospitalization and death from COVID-19. However, these aren't the only factors to consider. Part of the rationale for the recommending vaccinated individuals to wear masks indoors in areas of high transmission is to prevent the evolution of new strains that can potentially evade immunity.

Vanadium 50 said:
Is Delta more dangerous than other strains? Looks like it. Is it so much more dangerous that new drastic steps are necessary? That seems to be what the CDC (Science!) is telling us. but not what the data (anti-Science) is.
The CDC has changed its recommendations to recommend that fully vaccinated people wear masks indoors in areas of high transmission. This is less restrictive than the universal masking requirements in Ontario, which you cite as a good example of an area keeping SARS-CoV-2 transmission in check (in fact, your rather pesky data set would suggest that the CDC should institute more strict masking requirements). Requiring masks indoors (only in areas of high transmission) does not seem like a very drastic step to me. The cost (wearing a mask indoors) seems very low, while the benefit (lowering overall rates of transmission and lowering the risk of new variants evolving) seems much higher than the inconvenience of having to wear a mask indoors.
 
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  • #243
Ygggdrasil said:
Where did you get the R = 13 number?
Seems to be what the media is running with. But for the same reason it's not 13, it's not 9.

Ygggdrasil said:
The data cannot be used to conclude that vaccination w/o masking is sufficient to contain the spread of the Delta variant.
I never claimed that. And as far as the various "seems to mes" in your message, it almost sounds like you agree with me - this is intended to promote good behavior, even if not exactly true.
 
  • #244
Guessing the Delta variant having a higher R_0 value is due to current mitigating circumstances?
The growth slopes from the UK for both deaths and cases seem to match fairly well, but the Delta variant has a lower slope than the original variant attack.

UK.log.growth.slopes.2021-07-31 at 2.55.55 PM.png
 
  • #245
OmCheeto said:
Guessing the Delta variant having a higher R_0 value is due to current mitigating circumstances?
The growth slopes from the UK for both deaths and cases seem to match fairly well, but the Delta variant has a lower slope than the original variant attack.
I think that is because the UK is was quite highly vaccinated for Delta. Vaccination reduces Delta transmission by 40-80%. The increased R0 is supported, but likely overestimated by https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2021.26.24.2100509. It is overestimated in part because it is contaminated by looking at transmission in populations with some immunity from previous infections or vaccinations, and the transmission advantage may be due immunity causing to a larger decrease in Alpha transmission than Delta transmission (whereas we would like to know what R0 is without immunity, like for the original strain). With an attempt to have immunity taken into account, it is estimated that the R0 for Delta is 1.1 to 1.4x higher than for Alpha: https://www.researchsquare.com/article/rs-637724/v1. If original R0 is 2-3, and using 1.3-1.7x for Alpha, and 1.1-1.4x for Delta, a rough estimate for Delta R0 would be 3-7.

There is also discussion in the Eurosurveillance paper about whether factors like generation time affect their estimate. So it may be that having more infected people in a short time with Delta is not only due to a change in R0, but also a change in generation time.
 
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