Coronavirus

[AlanSubie4Life]

And then this (and yes, that really is his name):

The R0 is not likely 7 or 10.5. If it were, we’d be pretty hosed!

I also saw an article I can't find right now that Delta is hitting young people much harder than previous variants.

Probably because vaccination rates are so much lower in those groups. This is what I would expect and what we discussed here as being the next likely scenario, several months ago. Those differences in vaccination rates are going to completely change the demographics of those admitted to the hospital.

From those hand wringers at CNN:

I would definitely like them to dig a bit deeper, that is for sure. Let’s quantify! The qualitative takeaways seem to be that being unvaccinated is bad. And if you are vaccinated, you should still be careful (vaccine efficacy of course only goes to 100% when enough people get vaccinated), especially if you have pre-existing conditions or are otherwise vulnerable (old). I don’t think these are earth-shattering takeaways, though they do bear repeating over and over again.

 

[wdolson]

The R0 is not likely 7 or 10.5. If it were, we’d be pretty hosed!



Probably because vaccination rates are so much lower in those groups. This is what I would expect and what we discussed here as being the next likely scenario, several months ago. Those differences in vaccination rates are going to completely change the demographics of those admitted to the hospital.



I would definitely like them to dig a bit deeper, that is for sure. Let’s quantify! The qualitative takeaways seem to be that being unvaccinated is bad. And if you are vaccinated, you should still be careful (vaccine efficacy of course only goes to 100% when enough people get vaccinated), especially if you have pre-existing conditions or are otherwise vulnerable (old). I don’t think these are earth-shattering takeaways, though they do bear repeating over and over again.

It appears Delta is not has a higher r0, but is more lethal. @Jeff N reminded me of enough details to find the article
'We are seeing people passing quicker than before': What hospitals look like in US Covid hot spots

Even in populations where vaccine rates are low Delta is hitting healthier people much harder than previous variants. A few weeks ago someone here who has family in India was talking about how hard hit their own family was back in India. It's back about 10 pages.

According to this the R0 of the variants in circulation last fall was between 1.5 and 6.68
R0 and Re of COVID-19: Can We Predict When the Pandemic Outbreak will be Contained?

The Tweet @Jeff N posted from Larry Brilliant said the R0 of Delta looks like 2-3X. That would be between 3 (2X the lowest) and 20 (3X the highest). Measles is the most infectious disease out there and it's 12-18.

This article originally was from last year, but was updated in February (before Delta)
What is R0?

It had the Delta of COVID between 0.4 and 5.7. I think even what was going around last year was above the common cold (2-3) and the flu (0.9-2.1) because COVID raged on all winter and around the world there were very few colds and flu last year. The measures were were taking to combat COVID were slowing it down, but not stopping it and those same measures stopped cold and flu in its tracks. That means the strains of COIVD we were seeing last winter probably had an R0 around 4 or 5. Delta could be easily twice that. That puts it into polio and chickenpox range and close to measles. On the upper edge of estimation it could be in the ballpark of measles.

It looks likely that unvaccinated populations are going to get hit very hard by Delta. I know the regulatory bodies are moving with caution before approving the vaccine for children, but the race is on to get kids vaccinated before Delta goes everywhere. At this point we may not make it.

Another thing I recall seeing something last year that the level of exposure impacts how bad a case people get. I have read of more than one family where an unvaccinated kid got COVID and the rest of the family who was vaccinated got breakthrough cases. One was on a road trip and everyone had to ride back home in the same car with the sick kid. It may be that an intense exposure such as close proximity to an immediate family member with it raises the odds that the disease will defeat the defenses from the vaccine.

Another reason to get kids vaccinated. If entire households are vaccinated it will probably reduce breakthrough infections.

Doesn't help those who refuse to get the vaccine though.

I saw a British comedian describe a term used in the North of England. He used a word to describe it that would probably get me banned, but it essentially meant "idiot tax". He said the term was for the cost of doing something stupid. For example locking yourself out of the house and having to call a lock smith to get back in had an idiot tax for the cost of the lock smith. Unfortunately the idiot tax for not getting vaccinated can be very high.

 

[wdolson]

Interesting site... thanks for sharing Per capita covid-19 cases and deaths
Here is another view that shows the daily deaths per 100,000 persons... a key metric for the Western US States.

View attachment 684452

It is interesting that the per capita death map doesn't match the outbreak map very closely, but the death map may be representing people who were quite ill and lingered in the hospital for months before finally losing the fight? The actual death numbers on that map are generally pretty low so one death in a small county is going to pop out. The N at the moment is so small we're seeing a lot of noise in the results.

 

[AlanSubie4Life]

It appears Delta is not has a higher r0, but is more lethal.

Rather than a breathless CNN article with no data other than anecdotal evidence, wait for data on pathogenicity.

We need both mechanistic evidence and actual data from carefully conducted scientific studies to conclude “more lethal.” At the moment we have no evidence that Delta is more lethal. A higher viral load does not translate mechanistically to higher lethality, all on its own.

My prior is that it probably is about the same lethality. Waiting for evidence.

https://twitter.com/x/status/1415665138414194692

Get vaccinated!

Also, I believe a shorter serial interval will lead to this variant out-competing others without it actually being more contagious. Just because it spreads faster does not mean it is more contagious (in the R0 framework). Just leads to faster exponential growth with a shorter time constant. We’ll see. It may well be a bit more contagious. Maybe R0 of 5-6 or something.

 

[Jeff N]

Rather than a breathless CNN article with no data other than anecdotal evidence, wait for data on pathogenicity.

I’m surprised that this study from last month went completely unmentioned in the NYT article. It finds a doubled risk of hospitalization from Delta variant.

Study summary:

Delta variant doubles risk of COVID hospitalisation - Scottish study

The Delta coronavirus variant doubles the risk of hospitalisation compared with the previously dominant variant in Britain, but two doses of vaccine still provide strong protection, a Scottish study found on Monday.

www.reuters.com

Study details:
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01358-1/fulltext

 

[Jeff N]

It may well be a bit more contagious. Maybe R0 of 5-6 or something.

As for R0, I have more commonly seen the original Wuhan variant described as around 2.7 so doubling that for Delta would be around 5-6. The higher end of informed speculation I have seen in medical or scientific forums seems to be 8. Obviously these numbers are a bit hazy and more factors are likely involved than just simple transmissibility.

 

[AlanSubie4Life]

I’m surprised that this study from last month went completely unmentioned in the NYT article. It finds a doubled risk of hospitalization from Delta variant.

Study summary:

Delta variant doubles risk of COVID hospitalisation - Scottish study

The Delta coronavirus variant doubles the risk of hospitalisation compared with the previously dominant variant in Britain, but two doses of vaccine still provide strong protection, a Scottish study found on Monday.

www.reuters.com

Study details:
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01358-1/fulltext

You’d definitely like to see info on severity of hospitalized cases. There are so many factors! More hospitalizations does not necessarily mean it is any worse. Very hard to say. I did not read the paper.

 

[madodel]

You’d definitely like to see info on severity of hospitalized cases. There are so many factors! More hospitalizations does not necessarily mean it is any worse. Very hard to say. I did not read the paper.

If Delta is spread more widely and causes more cases, and more hospitalizations, aren't deaths going to follow the trend? Though from what I have also read death per case basis is the same. So lethality may be the same as Alpha, but we may be seeing those white trailers popping up due to overall numbers of actual deaths trailing hospitalizations. Has anyone read if the general timeline for the previous versions (event->2 weeks -> ↑cases-> 1-2 weeks-> ↑Hospitalizations-> weeks to months -> ↑deaths, applies the same to Delta? If it replicates faster wouldn't this be accelerated?

 

[AlanSubie4Life]

Delta is spread more widely and causes more cases, and more hospitalizations, aren't deaths going to follow the trend?

Hospital admission criteria are not fixed. Makes it really tricky to draw conclusions from hospitalization data. Paradoxically hospitals might also be more likely to admit young people who are very ill than older people who are very ill. For older people they may just throw in the towel or lean on the care teams at nursing homes, home care, to provide basic supportive care for cases that seem like they may not need hospitalization.

It’s also possible older people just die, while young people hang on, so that could increase hospitalization rates, since the demographics are shifted towards younger people.

If it replicates faster wouldn't this be accelerated

Yes, the serial interval seems a bit shorter so it’s possible the timelines will be accelerated by a few days. I don’t think it will become that noticeable since the overall time is something like a 4-5 week delay..

 

[AlanSubie4Life]

A good thread. Get vaccinated or get infected. Personally I doubt R0 is 6, but it is conceivable of course. It’s a tricky thing to measure, and shorter serial interval can skew the simple R0 estimations higher, I would guess. These are separable, but I do wonder how carefully these analyses are being done. (I haven’t bothered to look at any of the papers, since I tire of these details these days.)

https://twitter.com/x/status/1415587167863283713

 

[renim]

Delta would be more lethal, except for 2 points
1) treatments are much improved now
2) almost everywhere people have some level of immunity, be it prior infection or vaccination or both infection + vaccination.

if you want to look for a population that remains covid naive, look to the young (or to Australia/New Zealand), does delta affect them more than wild type or alpha?

 

[wdolson]

A good thread. Get vaccinated or get infected. Personally I doubt R0 is 6, but it is conceivable of course. It’s a tricky thing to measure, and shorter serial interval can skew the simple R0 estimations higher, I would guess. These are separable, but I do wonder how carefully these analyses are being done. (I haven’t bothered to look at any of the papers, since I tire of these details these days.)

https://twitter.com/x/status/1415587167863283713

By that formula if the R0 is now 6 and the vaccine is 90% effective, herd immunity is at 92.5%. For a 70% effective vaccine (some in use in other parts of the world), herd immunity is not achievable.

The data for Delta is still incomplete, but it looks to me that Delta is definitely worse than other variants. Southern Missouri is seeing the worst outbreak in the country. Springfield is the only city in that part of the state with significant health resources and they said they were topped out yesterday. They have been sending patients to other cities in the state, but Kansas City and St Louis are beginning to get maxxed out too. This included ICU beds.

Overall Missouri is about 40% vaccinated and the outbreak is worst in a part of the state where vaccination rates are very low, but we're seeing hospitals fill up faster than the worst of it last year with some segment of the population with immunity whether from having it or the vaccine. It's too early to tell if this is more lethal or not. If the death rate is on par with previous outbreaks or worse, we will know Delta is more lethal. If it's on par, it's more lethal because treatment techniques have improved and you would expect the death rate to go down. If ti goes up, Delta is much more lethal than previous variants.

Delta would be more lethal, except for 2 points
1) treatments are much improved now
2) almost everywhere people have some level of immunity, be it prior infection or vaccination or both infection + vaccination.

if you want to look for a population that remains covid naive, look to the young (or to Australia/New Zealand), does delta affect them more than wild type or alpha?

The two most populated states in Australia are in lock down now because of Delta outbreaks. I expect New Zealand is going to cancel the trans-Tasmin travel bubble soon.

 

[AlanSubie4Life]

By that formula if the R0 is now 6 and the vaccine is 90% effective, herd immunity is at 92.5%.

Yeah it's likely less than 90% effective at reducing infection, so basically herd immunity is impossible if that were the value of R0.

If it's on par, it's more lethal because treatment techniques have improved and you would expect the death rate to go down

I don't think state-of-the-art treatment has improved much over the last 6 months. There might be a better supply & variety of monoclonals I guess.

By that formula if the R0 is now 6

Yeah it's grim if it's 6. But I personally doubt it is 6. Lots of fear right now. Look at India's cases. It's not like everyone got it. They'll likely have a surge again in my opinion; they're not at herd immunity, but they didn't get the outbreak under control with an R0 of 6, I don't think. It's likely less than 6 if they can actually use NPIs and natural immunity & vaccination (22% first dose) to reduce infections.

The data for Delta is still incomplete, but it looks to me that Delta is definitely worse than other variants

I just think it's way too early to make that conclusion. I think we can say it has an advantage in terms of rate of spread. Is it more contagious? Not even sure we can say that. I tend to think it's likely a little more contagious. We need more studies on this.

Overall Missouri is about 40% vaccinated and the outbreak is worst in a part of the state where vaccination rates are very low, but we're seeing hospitals fill up faster than the worst of it last year

Just because they're filling up faster doesn't mean it's more contagious. It could just mean it spreads faster, and infects the population more quickly as a result. That is not necessarily the same as being "more contagious," if the contagious period does not change. Faster spread wouldn't change the herd immunity threshold in and of itself. Longer spread likely would because there would be more contacts - but even that depends also on the virulence and how quickly an individual becomes symptomatic and isolates out of necessity (bedridden or whatever). So the picture is unclear.

So, keep an eye on those numbers - it's possible that the peak could come faster as well. The decay will likely be faster too since the population is closer to the herd immunity threshold than it was previously.

 

[Jeff N]

If Delta is spread more widely and causes more cases, and more hospitalizations, aren't deaths going to follow the trend?

There will be many fewer deaths now because the most vulnerable people (old or with other health conditions) are much more likely to be vaccinated now.

The chance of death from an unvaccinated Covid-19 infection drops dramatically based on age but the drop in hospitalizations drops more slowly. In other words, younger people can still get severely ill and be hospitalized but rarely die.

 

[Jeff N]

I don't think state-of-the-art treatment has improved much over the last 6 months. There might be a better supply & variety of monoclonals I guess.

Agreed, except that the original Lilly monoclonal called bamlanivimab is evaded by Delta and can no longer be used. Regeneron still works and I think Lilly has a newer combo version that still works.

In any case, these treatments are expensive, in relatively short supply (I think), and are only really effective when given very early. Meaning, that they aren’t practical for most cases. They are mostly good for older people or others with a higher likelyhood of a bad outcome whose infections can be detected early. But a high percentage of those people are already vaccinated in much of the country anyway and in poor rural areas with low vaccination rates the medical infrastructure is probably not setup for using them well.

 

[Doggydogworld]

I'm still amazed by the May outbreak in Taiwan. This country did almost everything perfectly, getting people on the ground in Wuhan a week into January 2020 and enacting countermeasures before Beijing even knew what was happening. They avoided lockdowns and other draconian measures. Prior to May they'd experience twelve deaths in total. Twelve! On May 11 they recorded 11 new cases, with a seven day average of 8/day. This was an uptick, but still well below their all time record high day of 27 cases.

Six days later, on May 17, they had 543 cases.

The seven day average is back down to 24 cases/day and total deaths, which soared to 759, may stay under 1000. But it's amazing how quickly this thing can explode even with an exceptional public health system.

 

[wdolson]

There will be many fewer deaths now because the most vulnerable people (old or with other health conditions) are much more likely to be vaccinated now.

The chance of death from an unvaccinated Covid-19 infection drops dramatically based on age but the drop in hospitalizations drops more slowly. In other words, younger people can still get severely ill and be hospitalized but rarely die.

We'll see, though Delta appears to hit younger healthier people harder than previous variants. In the 1918 flu pandemic most of the deaths were among people under 30. Another strain of the same flu had gone around in 1890 and 1891. It gave partial or total immunity to a large percentage of the population who were alive then.

Delta may not be the worst variant. Over time it has evolved several times into worse strains and there are large swaths of the planet where vaccinations are few and far between. As the developed world gets vaccinated we need to push the extra supply out to the developing world to knock down the variants. At this point COVID may be with us forever, but we can knock it down to a much more minor thing with worldwide vaccinations.

I'm still amazed by the May outbreak in Taiwan. This country did almost everything perfectly, getting people on the ground in Wuhan a week into January 2020 and enacting countermeasures before Beijing even knew what was happening. They avoided lockdowns and other draconian measures. Prior to May they'd experience twelve deaths in total. Twelve! On May 11 they recorded 11 new cases, with a seven day average of 8/day. This was an uptick, but still well below their all time record high day of 27 cases.

Six days later, on May 17, they had 543 cases.

The seven day average is back down to 24 cases/day and total deaths, which soared to 759, may stay under 1000. But it's amazing how quickly this thing can explode even with an exceptional public health system.

View attachment 685098

I saw a news story on what happened in Taiwan. They had strict entry requirements last year, but started relaxing them just as Delta broke out. Once it got loose in the country it's been hard to stop.

 

[uujjj2]

They should put anti-vaxxers back under stay-home orders. The majority (especially kids) shouldn't have to suffer because of an ignorant and selfish minority.

 

[eevee-fan]

FOX 4 Dallas: Dallas resident has Monkeypox; believed to be first-ever case in Texas.

Dallas resident has Monkeypox; believed to be first-ever case in Texas

Dallas County Health and Human Services reports the person who tested positive is now isolated at the hospital to prevent the spread of the virus and is in stable condition.

www.fox4news.com

I guess it is good practice to mask up with or without covid risk...

 

[eevee-fan]

U.S. COVID Deaths Are Rising Again. Experts Call It A 'Pandemic Of The Unvaccinated'

Reversing a months-long downward trend, deaths from COVID-19 have begun rising steadily this week. More than 99% of the recent fatalities were among people who had not been vaccinated.

www.npr.org

Blue Wave 2022, 2024!