Naked Science Forum
Life Sciences => Physiology & Medicine => COVID-19 => Topic started by: set fair on 18/02/2021 12:57:54
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In the last 5 weeks the number of daily cases worldwide has halved. Something must be going on, anybody heard an explanation? Could the virus be inherrantly unstable?
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People are probably trying quite hard to avoid catching it, and are learning how to do so.
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The Christmas and New Year rush to get infected has finished, travel bans are beginning to bite, and Satan has vacated the White House.
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To some extent, we must be running out of unexposed people.
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Countries are in lock-downs, supressing spread.
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The oddity seems to be India where apparently the infection rate is anomalously low - the the extent that Test cricket is now permitted in half-filled grounds.
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Not as marked as India but the fall in the US is pretty dramatic - in terms of new cases per unit of population, it is very similar to the UK with (much?) less stringent measures.
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the fall in the US is pretty dramatic
Vaccination in the US can only account for at best 50 million people out of a population of 330 million- but in reality, much less than that, since it takes a few weeks to build a good immune response from the first dose of vaccine, and a few weeks to build an improved response to the second dose, 3 weeks later.
But maybe people see the vaccine as being so close, it would be a pity to catch COVID now, so they are being more careful?
I would put part of the fall down to Twitter (finally) implementing their house rules about distributing false and misleading information, and tweets that endanger public safety (ie banning Trump).
- That allowed the softer voices of infectious disease specialists like Dr Fauci, and the mask-wearing president-elect to be heard.
In the last 5 weeks the number of daily cases worldwide has halved
The US was responsible for a fair fraction of the diagnosed cases worldwide (many poorer countries did not have the capacity to test symptomatic or even dying patients).
So a fall in cases in the the US represents a fall worldwide.
- But perhaps the spectacular fall of a president caused people to question some of the free health advice he had been dispensing?
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I heard that a disease modelling expert predicted this fall last November, as he considers the disease to have a seasonal component (like other coronaviruses).
- But he is concerned that the variants now circulating in South Africa could lead to a third wave, at the end of the Northern summer.
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It throws up a lot of surprises, behaving differently in different countries. I heard some US body thought a US variant woud do what the UK variant did here. I'm not even guessing.
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I heard that a disease modelling expert predicted this fall last November, as he considers the disease to have a seasonal component (like other coronaviruses).
- But he is concerned that the variants now circulating in South Africa could lead to a third wave, at the end of the Northern summer.
I think that the virus does its own thing, comes and goes in waves. The measures that we try to take, such as lockdowns and vaccinations, probably don't make much difference.
We like to think they do, obviously, to keep up morale. It makes us feel that we're doing something. But given the nature of viruses, I doubt that our efforts have more than a marginal effect on how the pandemic progresses
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Vaccination absolutely does make a difference. Ask Israel.
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I think that the virus does its own thing, comes and goes in waves. The measures that we try to take, such as lockdowns and vaccinations, probably don't make much difference.
You really think that?
You don't know about New Zealand (and a few other places)?
Wow!
I can't imagine how you could pay so little attention to what is currently one of the most important things happening in the world.
Vaccination in the US can only account for at best 50 million people out of a population of 330 million
Yes and no. Give it a while and it's 50 million, plus the people that those 50 million might have infected plus the ones they would have infected and so on.We like to think they do, obviously, to keep up morale.
Smallpox was not eliminated by wishful thinking.
Why do you ignore obvious facts?
It makes you look like a fool or a troll- and neither option makes you look clever.
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Vaccination absolutely does make a difference. Ask Israel.
Or anyone who doesn't remember smallpox or polio. Or who hasn't had tuberculosis, measles, mumps, rubella, tetanus, cholera, typhoid or yellow fever despite being exposed to them.
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The photoperiod is known to influence immune functions, such as innate immunity. My own guess is that it explains why cases peaked around a week or two after the winter solstice, when innate defenses would start getting stronger and prevent infections, after doing the opposite in December and accelerating transmission. I also think that because innate defenses vary significantly in the population, it makes the threshold for herd immunity much lower, as the number of highly susceptible people go down with time; current models assume everyone is as likely to catch it and transmit it if they haven't caught it before or been vaccinated. This would explain why some US states had case counts peak even well before early January despite much less than 60%+ of their population having been infected.
In India, it seems cases have peaked in September just after monsoon season. Maybe by keeping people inside and by being rainy all the time, it lowers people's defenses. The flu is known to also peak at this time of the year. Countries with rainy seasons seem to have very different flu seasons from ours in North America. Australia had a relatively low case count peak a couple weeks after its winter solstice, when it was our summer in the northern hemisphere.
The main one I don't understand is South Africa and why their cases have peaked right in the middle of summer. They did peak during their normal winter, like in Australia, before this recent summer peak. I really hope their variant does not have some unique capability to spread faster in summer. The nearby countries have less precise data but seem to experience the same general pattern. The pattern is really strange because the first wave aligns with countries like Australia, just like when the flu would peak, but the second wave of South Africa aligns with the northern hemisphere and peaked in early January before going down fast. I would be curious to know what pattern coronaviruses typically follow in South Africa; in America, coronaviruses cause most fall colds and the coronavirus season mostly aligns with the flu season.
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cases peaked around a week or two after the winter solstice,
Call it Christmas and blame herd stupidity
some US states had case counts peak even well before early January
or Thanksgiving, ditto
Australia had a relatively low case count peak a couple weeks after its winter solstice
not a public holiday, and sensible national quarantine
South Africa and why their cases have peaked right in the middle of summer.
Christmas + summer holidays = stupidity squared!
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cases peaked around a week or two after the winter solstice,
Call it Christmas and blame herd stupidity
some US states had case counts peak even well before early January
or Thanksgiving, ditto
Australia had a relatively low case count peak a couple weeks after its winter solstice
not a public holiday, and sensible national quarantine
South Africa and why their cases have peaked right in the middle of summer.
Christmas + summer holidays = stupidity squared!
This is ridiculous unscientific, singular events can't cause the Rt to hit a certain level throughout a whole month and suddenly reverse it the next month. The events would cause a singular spike in Rt and it is not what happened. Are you suggesting that Australia's winter peak, and typical flu season in the southern hemisphere, is caused by people in the southern hemisphere celebrating their winter solstice on June 21? Or that the flu has been peaking for hundreds of years at around the same time just because of Christmas and people shopping in malls for gifts during the whole month of December?
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Rt to hit a certain level throughout a whole month and suddenly reverse it the next month.
Oh yes you can. That's the whole point of quarantine where the principal vector is other humans. It has been demonstrated time and again for at least the last 5000 years and forms the basis of infection control wherever it is practicable.
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Rt to hit a certain level throughout a whole month and suddenly reverse it the next month.
Oh yes you can. That's the whole point of quarantine where the principal vector is other humans. It has been demonstrated time and again for at least the last 5000 years and forms the basis of infection control wherever it is practicable.
You realize that many places in the world have reversed a significant part of their restrictions, including reopening schools months ago, and cases are still going down? You're suggesting that leaders all across the world, but almost only in the northern hemisphere, called each other to ensure their measures would be synced, even though they all used different measures and some places didn't add any and still saw cases drop similarly.
Your suggestion that "quarantines" would explain why the flu and coronaviruses tend to peak around December/January in the northern hemisphere is very dubious.
By the way, what we are doing right now has never been done before and is very different from the concept of quarantining new arrivals. Quarantining started in the 14th century with the plague, not 5000 years ago. SARS-cov-2 virus is already spreading in almost every single country, locking new arrivals is not going to stop it.
I think you're using quarantine liberally to mislead on purpose; I've heard people like you refer to social distancing/NPIs in that way, I'm not sure why you would do that. You seem to have no interest in having a scientific discussion; I'm done talking to you.
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The photoperiod is known to influence immune functions
And the hours of daylight (related to photoperiod) also correlates with temperature. Increasing hours of daylight leads to rising temperatures, and people are more inclined to go outside.
- Rise in temperature has a lag after the December 22 solstice, but usually more than 2 weeks.
Quarantining started in the 14th century with the plague, not 5000 years ago.
It is true that the Italian word "Quarantine" was coined in Venice during the plague. It represented the 40 days a ship had to anchor in the harbour before they could have contact with other people.
But there are older references, for example in the Jewish Torah/Christian Old Testament:
“Anyone with such a defiling disease must wear torn clothes, let their hair be unkempt, cover the lower part of their face and cry out, ‘Unclean! Unclean!’ As long as they have the disease they remain unclean. They must live alone; they must live outside the camp.
And quarantine is partly innate: if you have a viral infection, the natural interferon response makes you lethargic (less likely to go out and mix with other people) and produces a runny nose and other symptoms that people associate with a cold (which makes other people keep their distance).
- A recent paper showed that these effects happen in bats too.
See: https://en.wikipedia.org/wiki/Quarantine#History
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Your suggestion that "quarantines" would explain why the flu and coronaviruses tend to peak around December/January in the northern hemisphere is very dubious.
I made no such suggestion. This thread is specifically about COVID-19 and it is clear that wherever and whenever quarantine has been strictly imposed, the incidence of new cases has decreased sharply. This is entirely consistent with current scientific knowledge about the transmission of the disease between humans.
Not too sure what you mean by "people like" me. My name is a bit of a giveaway (archetypal British male) and I'm a healthcare scientist, but you didn't know that. Perhaps you could elucidate?
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singular events can't cause the Rt to hit a certain level throughout a whole month and suddenly reverse it the next month.
it explains why cases peaked around a week or two after the winter solstice,
Well; which is it?
If an event like the Solstice can affect covid rates then an event like Christmas can do so.
I'm done talking to you.
Bye.
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A small minority of people will catch the virus and die. But the vast majority won't - they'll survive. As they always have throughout human history. Otherwise we wouldn't be here.
Isn't all this modern faffing about with vaccines and "lockdowns" just wishful thinking? As if we could immediately stop a virus from doing its thing.
We should just ride the wave, and go on into the future. Where we can live together with Covid-19, as fellow biological organisms.
What's wrong with that?
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As if we could immediately stop a virus from doing its thing.
"Immediately" is a stretch.
But, in principle, we could do it in a month.
Everyone goes home and stays there except the military who, distribute food + essentials.
After a month the virus will be gone.
So would a lot of people.
And it's not very practical.
But the reality is we could do it.
https://xkcd.com/2287/
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Isn't all this modern faffing about with vaccines and "lockdowns" just wishful thinking?
No,
The hint is from countries that didn't do it properly (like the UK) compared to those that did like NZ.
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Isn't all this modern faffing about with vaccines and "lockdowns" just wishful thinking?
No...
As if we could immediately stop a virus from doing its thing.
I don't think anyone has argued that we would get immediate results.
We should just ride the wave
That causes hospitals to be overwhelmed (there is a county in the state where I live where the hospitals were routinely above 90% capacity for a while) and you get more people dying that way. Vaccinations will prevent deaths in the future.
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A small minority of people will catch the virus and die. But the vast majority won't - they'll survive. As they always have throughout human history. Otherwise we wouldn't be here.
Wrong. If you do nothing to prevent it, everyone will be infected, 20% will need acute hospital treatment, 10% will suffer longterm disability and 5% will die. That's why we do what we can to prevent it.
Isn't all this modern faffing about with vaccines and "lockdowns" just wishful thinking? As if we could immediately stop a virus from doing its thing.
To nobody's surprise, it works. As it has done for smallpox, polio, ebola,....That isn't my interpretation of wishful thinking.
We should just ride the wave, and go on into the future. Where we can live together with Covid-19, as fellow biological organisms.-
Only politicians use "we" to mean "you". And even Boris Johnson changed his tune once he had received a dose.
What's wrong with that?
So far, everything.
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"Immediately" is a stretch.
But, in principle, we could do it in a month.
Everyone goes home and stays there except the military who, distribute food + essentials.
After a month the virus will be gone.
So would a lot of people.
And it's not very practical.
But the reality is we could do it.
https://xkcd.com/2287/
It might have been a good idea to first have vaccinated health care workers, old folk's homes and essential workers plus the military and threaten a Wuhan style lockdown if we didn't (inevitable) obey the current lockdown. Not my favourite prime minister, but, I bet Thatcher could have pulled it off.
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The oddity seems to be India where apparently the infection rate is anomalously low - the the extent that Test cricket is now permitted in half-filled grounds.
To be strictly accurate, half of the ground sections have been almost full, while the remaining areas have been almost completely empty 🤣
There’s an interesting discussion of the possible factors influencing the current falling Covid rates in one of the recent BBC More or Less episodes: https://www.bbc.co.uk/sounds/play/p098579l
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There’s an interesting discussion of the possible factors influencing the current falling Covid rates in one of the recent BBC More or Less episodes: https://www.bbc.co.uk/sounds/play/p098579l
Thanks, looks like nobody knows. I hadn't clocked South Africa.
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The US data is down to interpretaion because there is the fall in cases is overlated by the triple whamy of thanksgiving, christmas and new year but it looks like tne underlying change started around november 12th. All the youtube comentators failed to clock that the surges they predicted didn't match what actually materialised.
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https://xkcd.com/2287/
A pizza-led recovery!
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I think everyone (even virologists) would be able to see what happened in the US if there were graphs of the doubling times of daily new cases and daily deaths. As it is experts are trying to explain something that happened in January when whatever happened, happened 7 weeks earlier.
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You can have two viral infections at the same time but some respiratory viruses don't like company eg flu. Perhaps the US had an epidemic of a mild but very infectious cold.
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The number of Covid cases gets small
When the Spring comes
But will increase
In the Fall.
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To some extent, we must be running out of unexposed people.
I've heard "Herd Immunity" being thrown around. But that is only a portion of the story.
A large portion of the population has been really good at avoiding getting the disease. So, the disease may have blasted through some of the retail clerks, and those individuals who are a little careless. But, there is a huge proportion of the population that is still susceptible.
India and Brazil are in the middle of their next wave of infections.
I think despite all the vaccination, there are signs of the USA heading into a fourth wave (spring 2020, summer 2020, fall/winter 2020, and now spring 2021). We are hitting Spring Break for students, and the Easter holiday for family reunions.
Hopefully many of the elderly and vulnerable will have gotten the vaccine, but that isn't universal.
With some luck, the fourth wave will just be a fourth ripple.
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Yes, herd immunity doesn't wash when Utah, Washington and Oregon all follow the national curve and these states are far from herd immunity.
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The dramatic drop in the US and Canada occurred about the same time as 3 variants of concern were taking over in other countries. If this was driven by the fact that there was growing immunity to the wild type due to number of people who had already had the covid, then where were the new variants in the US? Perhaps there was one (or more) which could infect people who had had he virus already but it went undetected because it caused much milder illness and infected people had no or minor symptoms and therefore didn't get tested.
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The photoperiod is known to influence immune functions, such as innate immunity. My own guess is that it explains why cases peaked around a week or two after the winter solstice, when innate defenses would start getting stronger and prevent infections, after doing the opposite in December and accelerating transmission.
Cases peaked in the US early january but the R number started to fall in mid November. So transmissions were decelerating in december. This is easiest to see on the "our world in data site" where you can truncate the graph to show just October to January.
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You can have two viral infections at the same time but some respiratory viruses don't like company eg flu. Perhaps the US had an epidemic of a mild but very infectious cold.
The virus would have to be very infectious to beat the masks and spread right across the US, so maybe it's a pathogen that spreads by fomites... and now they're telling us washing our hands is not so important, not that I'm suggeating the US deliberately released such a pathogen across the country.
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The virus would have to be very infectious to beat the masks and spread right across the US, so maybe it's a pathogen that spreads by fomites...
As far as I am aware mask use was not universal across the US and seems to have been split along political and religious lines. Response in various states appear to follow similar lines.
not that I'm suggeating the US deliberately released such a pathogen across the country.
Probably best not to mention it at all in that case. I’m sure there will be those who think you are.
and now they're telling us washing our hands is not so important,
That seems to be a response to more recent studies which shed more light on transmission risks. It’s good to be kept up to date, but that can confuse some people.