CDC Internal Delta Variant Presentation
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1. Slide 16 mentions India but the details aren't clear. Is this study's focus on breakthrough cases and spreading of Delta based off data in India? I know India was where Delta originated and that it blindsided them because COVID measures that worked well for previous variants did not work anymore - so does that simply mean that the most data on Delta happens to be in India due to the larger cumulative number of Delta cases there? And if so how applicable is that data to the US, given that the type of vaccine administered is different and may have different (reduced) efficacy compared to Pfizer or Moderna, and since other factors (population size, density, healthcare quality, etc) may also be different and influence the data?
2. The graphs on Slides 20-21 are unclear to me. My interpretation is that they have four different scenarios and are using the bottom-left one, which assumes a higher R0 representing the Delta variant, and a lower assumption of natural immunity of 5% - basically the more conservative outlook. The graph itself seems to be indicating a probability of increase in cases, and we presumably want to be below 0.5. The legend shows three colors for universal masking, masking of the unvaccinated, and no masking. But the graph itself has five color bands - are the other color bands just hybrids? So the color between beige and lilac represents some vaccinated people masking and all unvaccinated people masking? And no masking is not an option per this graph even at 100% vaccination, because the probability of cases increasing would be around 80% still? If the natural immunity is higher (the bottom-right graph), then there is no need for universal masking in nearly all levels of vaccination? Am I interpreting all that correctly?
>Given increased transmissibility, lower VE, and current vaccine coverage, NPIs needed to reduce transmission of Delta variant
>Masking:
>• Source control 40-60% effective
>• Personal protection 20-30% effective
>NO ADJUSTMENTS FOR OTHER INTERVENTIONS
>• e.g., no distancing, no isolation, no gathering restrictions
I'm... not sure about that? Delta is infecting people who just walk past each other in indoor spaces: https://www.wsj.com/articles/delta-variants-spread-outpaces-...
How can you get to 40-60% effectiveness if you have perfect mask wearing, but leave restaurants and bars open? Even wearing a N95 when going to the grocery store and post office or whatever isn't going to help if you then go to a bar and spend an hour maskless with your 100 closest unmasked friends.
Again, why would they recommend universal masking if they know for a fact that it wouldn't do anything? What's the point?
This is not true.
As I understand it the rolling reviews for mRNA vaccine approval are purely a matter of time to prove for real the length of efficacy of them, that's part of the risk/benefit analysis. Can only be done a day at a time....
On the last slide, “Next Steps for CDC”, they explicitly list:
> ▪ Prevention
> – Consider vaccine mandates for HCP to protect vulnerable populations
> – Universal masking for source control and prevention
> – Reconsider other community mitigation strategies
Which means they definitely think additional mitigations are worthwhile, but we must start with at least masking.
They have a hard job to communicate the specific recommended actions while remaining calm and not causing a panic or making people think that they are over reacting… with everyone ready to jump on them, I do not envy the job.
Slide 21, bold red text, surrounded by a red box: "Given higher transmissibility and current vaccine coverage, universal masking is essential to reduce transmission of the Delta variant"
If this is supposed to imply that restaurants need to be closed, I feel like it should instead actually explicitly say that, because it means firing a million people, again. If universal masking requires restaurant closing, then masking by itself won't do anything!
If masking by itself does nothing, then why dedicate two slides to just masking? If masking does nothing, why give it 40-60% effectiveness? If the graph is totally worthless and means nothing useful, why put it in the presentation?
If closing restaurants is mission critical, absolutely required for any other NPI to have any effect at all, then why hide it inside "Reconsider other community mitigation strategies" on the last slide?
If additional stuff is done, then the risk goes down. It does not say how much, maybe a little, maybe a lot. But such other mitigations are unlikely to happen if the easiest, most effective and most accepted way, wearing masks, is not enforced already. That's why it makes sense to look at the case of masks-only.
That combined with how much more infectious this is makes it truly worrying.
One interpretation of the fact that Israel has such different numbers on vaccine effectiveness is that effectiveness starts dropping ~6 months in.
We'll need to start doing 3rd shots for lots of people ~now.
IMO the world just got a lot darker.
- lower your own chances of symptomatic disease, severe illness, hospitalization and death
- and therefore, help keep the healthcare system from collapsing
Delta variant vaccine breakthrough cases may be as transmissible as unvaccinated case
This refers to registered cases. Registered cases ~ symptomatic cases above certain threshold of symptoms (e.g. if you only have running nose or no symptoms whatsoever, you won't report anything).
Suppose you have two separate groups of 100 people, one with all vaccinated, other with none vaccinated. In each, 1 member is sick and gets in contact with everyone. In unvaxxed group, say, you get 20 symptomatic cases, 30 asymptomatic cases, and 50 are lucky. In a vaxxed group (an example), you get 3 symptomatic cases, 10 asymptomatic cases, and 87 are lucky. Now according to my understanding the slide statement above applied to this though experiment says that every one in the 20 symptomatic cases from unvaxxed group has the same chance (individually) to transmit, as everyone of the 3 symptomatic cases of vaxxed group. But because vaxxed group has 6x less people on stage 2 who could transmit further, overall transmission rate is also almost 6x lower.
E.g. the statement talks about sending chances, and not receiving chances. And overall transmission depends on both.
I need more time to digest this presentation, but there are two important topics that I feel are missing or at least underrepresented:
1) The effectiveness of early outpatient treatment using a combination of existing medicines (antibiotics, corticosteroids, antiplatelet/antithrombotic) [0a] [0b]
2) The risk of vaccine induced immune escape
Regarding 2) The basic idea is that imperfect vaccines may cause selective pressure which further enhances the fitness of highly virulent pathogens. This may be particularly relevant to the widely deployed mRNA vaccines, which induce an immune response that is highly targeted towards the SARS-CoV-2 spike protein.
Here are some peer reviewed publications on the topic, along with a few excerpts [1][2][3][4][5][6]. To be clear, the excerpts I'm providing below do not contradict any of the major points from the presentation. However, I do hope they illustrate that there is another important dimension to discuss when evaluating the evolutionary dynamics of SARS-CoV-2.
Excerpts from [1]:
- "A growing body of evidence suggests that the targets of several human vaccines are evolving"
- "For example, resistance to influenza and herpes-virus drugs emerged within a few years of FDA approval, and resistance to antivirals rapidly arises within human immunodeficiency virus (HIV) and hepatitis C virus (HCV)-infected patients"
- "The best documented example of vaccine resistance evolution occurred in Marek’s disease, a commercially important disease of chickens caused by Marek’s disease virus (Gallid herpesvirus II). There, two generations of vaccines were undermined by viral evolution. Those vaccines prevented disease, but even before the pathogen evolved, they did not prevent viral infection, replication, or transmission. Instead, Marek’s disease virus reached large population sizes even within vaccinated hosts and was able to transmit to new hosts. As a result, the virus was likely able to generate genetic diversity within vaccinated hosts, and vaccine-induced selection was able to act during transmission between hosts. The benefits of prophylaxis were thus missing."
Excerpts from [2]:
- "Here we show experimentally that immunization of chickens against Marek's disease virus enhances the fitness of more virulent strains, making it possible for hyperpathogenic strains to transmit. Immunity elicited by direct vaccination or by maternal vaccination prolongs host survival but does not prevent infection, viral replication or transmission, thus extending the infectious periods of strains otherwise too lethal to persist. Our data show that anti-disease vaccines that do not prevent transmission can create conditions that promote the emergence of pathogen strains that cause more severe disease in unvaccinated hosts."
Excerpts from [3]:
- "The spike protein receptor-binding domain (RBD) of SARS-CoV-2 is the molecular target for many vaccines and antibody-based prophylactics aimed at bringing COVID-19 under control."
- "Such a narrow molecular focus raises the specter of viral immune evasion as a potential failure mode for these biomedical interventions. With the emergence of new strains of SARS-CoV-2 with altered transmissibility and immune evasion potential, a critical question is this: how easily can the virus escape neutralizing antibodies (nAbs) targeting the spike RBD?"
- "Our modeling suggests that SARS-CoV-2 mutants with one or two mildly deleterious mutations are expected to exist in high numbers due to neutral genetic variation, and consequently resistance to vaccines or other prophylactics that rely on one or two antibodies for protection can develop quickly -and repeatedly- under positive selection."
- "Strategies for viral elimination should therefore be diversified across molecular targets and therapeutic modalities"
- "The speed at which nAb resistance develops in the population increases substantially as the number of infected individuals increases, suggesting that complementary strategies to prevent SARS-CoV-2 transmission that exert specific pressure on other proteins (e.g., antiviral prophylactics) or that do not exert a specific selective pressure on the virus (e.g., high-efficiency air filtration, masking, ultraviolet air purification) are key to reducing the risk of immune escape"
Excerpts from [4]:
- "... evidence for vaccine-induced disease evolution is mounting for many diseases ..."
- "... vaccines can reduce parasite fitness by preventing infection, reducing within-host growth, or preventing transmission. These have been shown to have very different evolutionary consequences for parasite virulence evolution"
- "Vaccines which reduce within-host growth rates are predicted to increase virulence"
- "Infection with multiple strains of the same parasite can result from separate infection events of co-circulating strains, or because the parasite has a rapid mutation rate and generates strain diversity through mutation within the host. Biologically, distinctions between ‘types’ of multiple infection matter because they affect the relatedness of the co-infecting parasites and relatedness can influence the optimal virulence strategy for the parasite"
[0a] Pathophysiological Basis and Rationale for Early Outpatient Treatment of SARS-CoV-2 (COVID-19) Infection (2020) https://www.amjmed.com/article/S0002-9343(20)30673-2/fulltex...
[0b] Multifaceted highly targeted sequential multidrug treatment of early ambulatory high-risk SARS-CoV-2 infection (COVID-19) (2020) https://scholarlycommons.henryford.com/cgi/viewcontent.cgi?a...
[1] Why does drug resistance readily evolve but vaccine resistance does not? (2017) https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2016...
[2] Imperfect Vaccination Can Enhance the Transmission of Highly Virulent Pathogens (2015) https://journals.plos.org/plosbiology/article?id=10.1371%2Fj...
[3] Risk of rapid evolutionary escape from biomedical interventions targeting SARS-CoV-2 spike protein (April 2021) https://pubmed.ncbi.nlm.nih.gov/33909660/
[4] The adaptive evolution of virulence: a review of theoretical predictions and empirical tests (2015) https://www.cambridge.org/core/services/aop-cambridge-core/c...
[5] The phylogenomics of evolving virus virulence (2018) https://www.nature.com/articles/s41576-018-0055-5
[6] Monitor for COVID-19 vaccine resistance evolution during clinical trials (Nov 2020) https://journals.plos.org/plosbiology/article?id=10.1371/jou...
So the CDC made a grave error in telling vaccinated people they could remove their masks.
A broader perspective and perhaps a better takeaway is that to mitigate this pandemic it seems we - collectively as a society - need to focus on more sophisticated & multi-faceted strategies beyond the current mRNA vaccines, lock-downs, and masks.
99.9785% of vaccinated are not infected 99.8714% of un-vaccinated are not infected
99.9999% of vaccinated are not hospitalized 99.9975% of un-vaccinated are not hospitalized
99.99996% of vaccinated are not dead 99.99904% of un-vaccinated are not dead
This is such a small difference.
But maybe if you count infections per second, instead of per week, you can get a number so close to 100% not dead that it’s a rounding error: pandemic solved!
>Given higher transmissibility and current vaccine coverage, universal masking is essential to reduce transmission of the Delta variant
Well that's very sad, if not entirely unexpected. How long will we be living in a masked world?
There are plenty of experts and health officials who believe that eradicating the pandemic is possible. Including some with experience eradicating other pandemics like Ebola and Zika [1], along with the editor-in-chief of the Lancet [2], among others.
Eradicating a pandemic is not unprecedented, it can and has been done.
> If you've gotten the impression that our public health response is about reaching some future point where Covid-19 is gone and nobody ever has to worry about it, you're being misled.
Clearly our COVID19 response is not currently about that, or no one would have to advocate for it.
[1]:https://necsi.edu/corona-virus-pandemic. (Ebola: https://necsi.edu/ending-pandemics)
I have to concede that he's not a crank, and appears to have meaningful pandemic expertise. I'm now aware of one expert who's confident eliminating Covid is possible. But this has to be evaluated in the context of the overwhelming consensus (https://www.nature.com/articles/d41586-021-00396-2) that it's probably not, and these sites are structured as grand calls to action more than detailed arguments, so it's hard for me to figure out what the content of the disagreement is. What does Bar-Yam know that immunologists don't?
As for the disagreement, it probably stems from the fact that with other outbreaks like Ebola, with known ~50% mortality rates, there’s unanimous consensus that they must be shut down early, and so they are.
That common cause and singled-minded focus and coordination is a major factor in successfully eradicating the pandemic. And doing it early before it can become widespread is obviously more viable than shutting it down after it’s gone global.
These folks are asserting that the methodologies used for shutting down other pandemics early can still be effectively scaled up to shut down a widespread pandemic like COVID19 that we failed to shut down early. And that’s where the disagreement is with the consensus you linked.
The thing is, global pandemics aren’t over, they’re just beginning, and we could be hit by something worse later. It behooves all of society to use COVID19 as a not-too-deadly trial run for learning how to quickly shut down something worse in the future, rather than fatalistically accepting it.
I think this is the core thing that I've never understood about the zero covid idea. If you look at, say, France or Spain, there was a unanimous consensus that the coronavirus must be stopped early, with strong and severe lockdowns for 5-6 weeks as these sites outline. The consensus didn't break because of laziness or complacency; it broke because it didn't work, because the lockdowns reduced but never eliminated community transmission. If you have a disease that's not that bad in the scheme of things, and you try the best known suppression strategies but they don't get rid of it, what other option is there than to find a way to live with it?
I also think it's important to acknowledge that our efforts to fight Ebola have not generally been this strong, despite Bar-Yam's arguments that they should be. In 2014, some American states imposed mandatory quarantines on doctors and nurses who'd been treating Ebola patients in western Africa, and there was strong pushback - from medical experts, who said that the quarantines were stigmatizing and counterproductive and there's no medical reason to impose such an over-the-top policy. "The Ebola quarantines and other movement restrictions put in place throughout the nation beginning in late 2014 were motivated by fear and by politics, not by medical science", said Doctors Without Borders.
Their critique of most of those cases is the measures were lifted prematurely, before getting all the way to zero infection rate, allowing it to re-spread again. And also the fact that all adjoining countries need the same zero-covid policy, or even ones that get to zero covid can be reinfected by neighbors. It's all (the way to zero), or nothing.
A piece of ordinary cloth on your face does not filter smog, does not prevent any airborne infection droplets from reaching you, essentially only lowers the chance of your cough hitting somebody else. You need an N95 or better to really do anything to protect yourself. Also even if you have a high grade mask, wearing it so it actually seals to protect you is hard and most people don't do it well.
Masks do more to protect others than they do you. Which is why we are safest when everyone wears a mask.
When the checkout queue is moving slowly, some people try to move the queue forward by moving closer tho the person in front, even though the queue hasn't moved. I've noticed that people who do this are always maskless.
My local store is near a homeless shelter; homeless people face much greater threats than what amounts to a nasty respiratory virus. But I like social distancing; it tends to improve my sense of having personal space, as well as making me feel safer.
So I have to accept there's a way of thinking that makes it actually wrong to mask-up.
Incidentally, I walked off the street into a pub the other day, for a straight whisky at the bar - I didn't plan to hang around (nobody was masked, of course, because you can't drink through a mask). Well I was basically called out by this grumpy fella, because I came in masked. I mean, he was joking, but he obviously despised me.
https://www.cdc.gov/eid/article/26/5/19-0994_article
> Disposable medical masks (also known as surgical masks) are loose-fitting devices that were designed to be worn by medical personnel to protect accidental contamination of patient wounds, and to protect the wearer against splashes or sprays of bodily fluids (36). There is limited evidence for their effectiveness in preventing influenza virus transmission either when worn by the infected person for source control or when worn by uninfected persons to reduce exposure. Our systematic review found no significant effect of face masks on transmission of laboratory-confirmed influenza.
I have one that I use when woodworking / sanding / varnishing, and the difference between a respirator and even a good N95 mask is like night and day. You can pull in a gratuitous volume of air through the respirator and it doesn't have that "there is a disconcertingly noticeable quantity of VOCs getting past this N95 mask" smell to it.
VOCs getting past a well-fitting N95 mask is working as intended, isn't it? N95 filters particulates only.
I have a 6000 series with bare P100 filters installed, and they certainly cut smells, but that's probably not what they're designed for. Amusingly, throughout this entire pandemic I've only worn it for wildfire smoke-- it appears to be completely impossible for people to understand what I'm saying while I'm wearing it.
If someone sees mask wearing instead as a joint effort to fight the pandemic, as means to get out of it earlier by limiting the spread of the disease or as a way that they can do something to protect themselves no matter what others might do, then it is absolutely not depressing. Self-efficacy influences mood positively a lot.
People here also walk around with masks during allergy season, or doing flu season even when they’re not sick. In Taiwan and Vietnam I saw (and wore) masks on days when the air was particularly dirty.
I suspect the Venn diagram of people who don't like masks and people who don't like coercively collectivist politics is basically a circle. It certainly is here in the UK, most opposition to masks in Parliament came from the Tory backbenchers which I guess is why their mandatory use was dropped this month; the 1922 Committee (a formal group of Tory backbenchers) can force a vote of no confidence in the Tory leader if 15% of them call for such a vote. Tory backbenchers tend to be more small-c conservative than the Tory frontbench, they're not necessarily anti-authoritarian but they're often anti-collectivist.
Not everything is politically motivated.
Also I don't know how people do it with having to smell their own breath for long. Regardless of how well the oral hygiene is, breath gets bad after eating some food.
Also cloth masks are pretty much useless considering their penetration level of 97%. Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4420971/
> Penetration of cloth masks by particles was almost 97% and medical masks 44%. This study is the first RCT of cloth masks, and the results caution against the use of cloth masks. This is an important finding to inform occupational health and safety. Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection. Further research is needed to inform the widespread use of cloth masks globally. However, as a precautionary measure, cloth masks should not be recommended for HCWs, particularly in high-risk situations, and guidelines need to be updated.
https://www.cdc.gov/eid/article/26/5/19-0994_article
> Disposable medical masks (also known as surgical masks) are loose-fitting devices that were designed to be worn by medical personnel to protect accidental contamination of patient wounds, and to protect the wearer against splashes or sprays of bodily fluids (36). There is limited evidence for their effectiveness in preventing influenza virus transmission either when worn by the infected person for source control or when worn by uninfected persons to reduce exposure. Our systematic review found no significant effect of face masks on transmission of laboratory-confirmed influenza.
> We did not consider the use of respirators in the community. Respirators are tight-fitting masks that can protect the wearer from fine particles (37) and should provide better protection against influenza virus exposures when properly worn because of higher filtration efficiency. However, respirators, such as N95 and P2 masks, work best when they are fit-tested, and these masks will be in limited supply during the next pandemic. These specialist devices should be reserved for use in healthcare settings or in special subpopulations such as immunocompromised persons in the community, first responders, and those performing other critical community functions, as supplies permit.
Not really though.
And why not say it. The fact the government is forcing me to wear a mask indoors makes me want to get rid of it asap.
Masks were not great for mental health, but apparently that doesn’t matter as much as virtue signaling.
Forever, because too many self-centered people refused to do the few simple things it would have taken to get the situation even remotely close to under control. It's already gone on longer than it needed to, and because of human selfishness it's almost certainly just going to get worse.
We won't be. People will simply be unwilling to do so long term and what doesn't get prevented by vaccines will burn through the population until everyone has antibodies and the disease weakens and "the common cold kills people" becomes the new normal.
There have always been diseases around that killed people, we were lucky for quite a while because the rate was fairly low and now it seems to be permanently bumped up a bit again. Eventually the disease is going to run out of people to infect the first time.
VE for Delta apparently wears off after ~180 days.
Edited to add: I suppose it depends on their methodology. Quick glance at Thompson’s study, seems they compared vaxxed HCWs to unvaxxed HCWs. I don’t know if we would expect to see material PPE-wearing differences between those groups.
https://covid.cdc.gov/covid-data-tracker/#demographicsoverti...
Cases are increasing but even case increase is a tiny blip compared to winter. Cases have always been a poor metric to judge the pandemic as it doesn’t indicate the severity of the infection. Filter the graph by deaths and we can see COVID deaths have still yet to increase even a tiny amount from their already extremely low levels after vaccinations become mainstream. Yes there is a lag time between death and cases but that lag time is only two weeks.
If you look at the US as a whole cases are not are still well below the worst daily averages of last Christmas, but blip is a much stronger word than I'd use when the trend line is pointed up with no obvious end in sight.
Drill down on the individual states with the most issues and you'll see that places like Louisiana are basically at the same point as they were in winter and will likely far exceed it.
As you say, the fact that most of the most vulnerable age ranges have been vaccinated will certainly help the death tolls. The flip side of that, however, is that a much higher concentration of the deaths in those states are going to be younger individuals.
Just because they were wrong doesn’t mean that they didn’t make the best decision possible with the available information and given circumstances.
I will also note Israel has already approved a third dose of mRNA booster shots for 60+ year old people based on the data they have seen with waning efficacy. The CDC as of now currently says boosters are not necessary for Americans "at this time"...
This and the fda authorization of the biogen drug have sealed the deal for me on how corrupted the US has become. It’s been coasting thanks to the good decisions made decades past, and finally it’s just fumes and the time couldn’t be more perfect.
Maybe it has? For example, DC has reported 11 homicides since its last reported COVID death.
Unless you think it’s normal that American society has more mass shootings than I can keep track of in recent memory then i’d call it an epidemic.
People walking into churches, schools, concerts, etc… and indiscriminately killing people is a deep sickness in American society.