Continuation The One Covid-19 Science and Medicine Thread Part 3

[marting]

In the beginning of this fomite transmission was considered the primary transmission mode. Then droplets within 1-2 m. was added. It really took a fair amount of evidence before aerosol spread was added and has been increasingly accepted as a major vector. Especially in superspreader events.

But, as difficult as it is to determine fomite transmission was the mechanism, there are a few cases where it's pretty clear. In China an outbreak was linked to imported seafood. An obvious case where low temps kept the virus viable.

Likely fomite tranmission remains a low probability mechanism but in conditions where temps are low such as outdoor handrails, handles, and other things people touch, the tranmission is going to be much more in the winter. So if fomite transmission is 5% of the total in summer, it could well be 10% or more in the winter.

We just don't know what the specific factors are. But the problem with fomite transmission is that you really can't effectively contact trace and it has the potential for wide geographical seeding.

[The Atheist]

Originally Posted by marting

In the beginning of this fomite transmission was considered the primary transmission mode.

I'm not sure it was ever considered the primary means of transmission, but maybe undue emphasis was placed on it early on.

As you say, it's a pity these things can't be tested, but that's one of the limitations of dealing with a disease than can kill you.

[Skeptic Ginger]

Droplet spread is always considered some droplets to the face and some surface contamination.

[!Kaggen]

I apologise if this has already been addressed in this thread but I had a question regarding herd immunity and Covid-19 vaccines.
If a Covid-19 vaccine only has a guaranteed immunity period of say 3 months what percentage of the population would need to be immunised to achieve herd immunity?

[Skeptic Ginger]

I wouldn't worry about it, the reason it is speculated the vaccine might only last 3 months is because it hasn't been studied longer. People often don't understand that.

[marting]

Originally Posted by !Kaggen

I apologise if this has already been addressed in this thread but I had a question regarding herd immunity and Covid-19 vaccines.
If a Covid-19 vaccine only has a guaranteed immunity period of say 3 months what percentage of the population would need to be immunised to achieve herd immunity?

I'm encouraged. Given the case ramps over the last month and initial infections in March/April, if there was a material loss of immunity within the 8 months we would have strong evidence of re-infection. Only sporadic reports which are to be expected. Some people have poor immune responses.

[Rolfe]

Originally Posted by !Kaggen

I apologise if this has already been addressed in this thread but I had a question regarding herd immunity and Covid-19 vaccines.
If a Covid-19 vaccine only has a guaranteed immunity period of say 3 months what percentage of the population would need to be immunised to achieve herd immunity?

Just the same as if it lasted for 10 years. The only difference is that you'd need to vaccinate all these people in less than three months. Indeed, you'd probably need to go round and boost them all at least once before their first round of protection ran out.

Fortunately the vaccines are going to last longer than that.

[Matthew Ellard]

Originally Posted by Bubba

https://www.sciencedirect.com/scienc...24857920304350

Hilarious Bubba. You didn't actually read the paper yourself again.

In simple terms, in your own words, does the paper say cardiotoxicity increases with use of Hydroxychloroquine or not?

Does the paper have any comment on whether Hydroxychloroquine is a remedy for Covid 19?

[arthwollipot]

One locally acquired case in Sydney. The driver of a van that ferried overseas airline crews has tested positive. It's likely that he picked it up from an American crew.

[Modified]

New information (to me) on actual vs. reported cases. https://www.economist.com/graphic-de...-with-covid-19

Based on their model the current multiple is about 2.5. Given the timing of North Dakota's cases, that would mean about 1/3 of the population of the state has been infected, assuming they are testing similarly to the US in total.

[marting]

Originally Posted by Modified

New information (to me) on actual vs. reported cases. https://www.economist.com/graphic-de...-with-covid-19

Based on their model the current multiple is about 2.5. Given the timing of North Dakota's cases, that would mean about 1/3 of the population of the state has been infected, assuming they are testing similarly to the US in total.

Sounds about right. Looks like they have been hit pretty hard. About 1 out of every 650 or so have died to date. Interesting how testing has recently been missing fewer people. Back in April it looked like 9 out of 10 were missed. Might have had to be almost sick enough to go to the hospital to get tested.

[Roger Ramjets]

Originally Posted by wobs

New variant in South East England:
https://www.bbc.co.uk/news/health-55308211

Same as this one?

Mutated form of Covid has been found in Wales, Scotland, Denmark and Australia and is now spreading quicker than dominant strain

Quote:

Members of the UK's Covid-19 Genomics UK Consortium (COG-UK) said today that the variant appeared to have emerged in England and then spread across the UK.

And one warned that it appears to be spreading faster than the dominant strain, which was imported by holidaymakers from Spain in the summer and now accounts for the majority of infections.

Experts researching the variant of the virus today said there was no hard evidence that this version could spread any faster, but that it was increasing at a far greater rate than any other strain in the country, which they are 'concerned about'...

There is some concern that the mutated strain could be a shape that is not well recognised by the immune system and that vaccines might not be as effective. The UK's Covid-19 Genomics UK Consortium said it was investigating this and also looking into 'whether or not any of these mutations are contributing to increased transmission'.

When is everyone going to realize that this virus is not be toyed with?

The more people we let it infect the faster it can mutate. We spent months developing a vaccine which is just starting to be rolled out now, but the virus is already one step ahead of us.

[Aridas]

Originally Posted by Roger Ramjets

Same as this one?

Mutated form of Covid has been found in Wales, Scotland, Denmark and Australia and is now spreading quicker than dominant strainWhen is everyone going to realize that this virus is not be toyed with?

The more people we let it infect the faster it can mutate. We spent months developing a vaccine which is just starting to be rolled out now, but the virus is already one step ahead of us.

Luckily, we're still at the "could" and "might" stage there and they made it quite clear that they don't have good evidence to back up the worst speculations. Hopefully, it will be another case of not different enough to matter. Too soon to say that the virus is already one step ahead of us, in short. That doesn't lessen your point that the virus shouldn't be allowed to spread like crazy, though.

[arthwollipot]

A worrying development in the driver's story. He apparently went to a sporting event while infected. All people at that event are now being treated as casual contacts.

[The Atheist]

Originally Posted by Roger Ramjets

The more people we let it infect the faster it can mutate.

Oh bravo!

Very few people understand that point. Just as people utterly failed to understand exponential growth until it happened, the vast majority of people have no clue about the likelihood of mutation.

To date, we have seven major mutations found.

Nobody really knows what that means yet, but if we've had 350-700m cases worldwide to date, then it's likely we'll see at least 70 more significant mutations in its first run, increasing the chances of a dangerous mutation.

Originally Posted by arthwollipot

A worrying development in the driver's story. He apparently went to a sporting event while infected. All people at that event are now being treated as casual contacts.

I see it was just a local soccer club, so should be a piece of cake in the unlikely event he infected anyone. Kids' soccer, so probably outside all the time. No wuckers.

[rjh01]

Originally Posted by arthwollipot

A worrying development in the driver's story. He apparently went to a sporting event while infected. All people at that event are now being treated as casual contacts.

Lucky there probably were not many people there. Just parents. And outdoors. But of course, doubt if anyone would be wearing masks. I would hate to be one of the people who talked to that person.

However

Quote:

New South Wales Health has just issued an alert that two more people have tested positive to Covid-19. The two people, a man in his 70s and a woman in her 60s live in the Northern Beaches area and there are no links at this stage to other known cases

https://www.theguardian.com/australi...08758977b3f1e4

Edit. My first part of the post is saying the same thing as The Atheist above.

[arthwollipot]

Yeah, I was just about to post that too. That's a worry. But I'm sure they'll trace those two infections pretty soon. They know what they're doing now.

[SophieWaggner83]

When is it all over and we live in peace. I so hope this year will be much easier than 2020! I wish you all success and health! Everything will be fine!

[The Atheist]

Originally Posted by SophieWaggner83

When is it all over and we live in peace. I so hope this year will be much easier than 2020! I wish you all success and health! Everything will be fine!

I hope you're right!

Certainly, the year is finishing on a more positive note than it started.

And welcome along!

[jnelso99]

Even with vaccines, there's too many stupid people in America that there's no chance of returning to any kind of normalcy until (my w.a.g.) at least this time next year.

Someone on Twitter (or somewhere) summed it up: The phrase "avoid like the plague" should be retired since it turns out people don't actually do that.

[xjx388]

My clinic was approved to be a vaccine distribution site for our area. We should have vaccines, in clinic, early next week!

As volunteer subject for the Moderna Study, which my clinic was also a site for, I expect that Moderna will unblind subjects in the next few days and give all placebo recipients the vaccine. I don't know which I am, but I had zero reactions to the shots I got so I've always just assumed I got the placebo.

We might just be rounding the corner! I think this would be a good time to initiate some lockdowns and get the vaccine working, but it will never happen.

[arthwollipot]

Originally Posted by The Atheist

Certainly, the year is finishing on a more positive note than it started.

This time last year my sky was a deep orange.

[marting]

Ars-Technica has a good writeup on the Moderna vaccine.

https://arstechnica.com/science/2020...it-looks-good/

Great chart showing cases v time in the placebo and vaccinated groups. Within 15 days they start to diverge and the vaccinated group stays quite low.

This is encouraging. If the highest risk groups (older and/or compromised) along with health care workers get vaccinated first death rates will drop. And that drop will be much faster than the drop in new cases simply because the at-risk group fatality rate is so much higher.

I hope they publish data on the demographics and numbers of people vaccinated over time.

[The Atheist]

The summer theory is starting to lose a bit of weight at the moment. South Africa is undergoing a strong second surge right now.

And if anyone understands what's happening in India, let me know - I think they've just stopped counting.

[arthwollipot]

I saw an article, I think, yesterday, that said that India's daily new case count has dropped below 3,000 for the first time in a timeframe I don't specifically recall.

[The Atheist]

Originally Posted by arthwollipot

I saw an article, I think, yesterday, that said that India's daily new case count has dropped below 3,000 for the first time in a timeframe I don't specifically recall.

It would've been below 30,000, and it's the lowest since June.

If you believe a bar of it, which I don't. Their numbers have been bull from the start, but when 18 million people die every year there anyway, who the hell would know?

[arthwollipot]

Originally Posted by The Atheist

It would've been below 30,000, and it's the lowest since June.

Yeah, probably. I only saw it in passing.

[ohms]

Insufficient evidence for effectiveness of Vitamin D in treating or preventing Covid-19 says UK panel:

https://www.nice.org.uk/news/article...e-on-vitamin-d

They say that more high quality studies are needed.

Edit:
Link to the report:

https://www.gov.uk/government/public...act-infections

[Garrison]

This Bloomberg article isn't exactly encouraging about vaccine uptake. France is the worst at 54% being willing to take the vaccine but others like the USA aren't that much better:

https://www.bloomberg.com/opinion/ar...-against-covid

[Modified]

Originally Posted by Garrison

This Bloomberg article isn't exactly encouraging about vaccine uptake. France is the worst at 54% being willing to take the vaccine but others like the USA aren't that much better:

https://www.bloomberg.com/opinion/ar...-against-covid

I would have to see the exact wording, but it says they asked people if they would get it "when it's available". Those people don't know that for them it will be available in July or something. Most just don't want to be first in line, and won't have that opportunity anyway.

[xjx388]

Our clinic is getting 500 doses next week!

In the meantime, just about every employee and clinician has gotten the vaccine in the first wave of 10,000 vaccines in our county, including my wife and my son. I’m a subject in the Moderna trial and they will be unblinding tomorrow and giving the vaccine to the placebo group. If I’m placebo, I should get mine tomorrow or Monday.

I’m very happy to see the doctors, nurses and other healthcare providers tweeting positively about their experiences. I think that might help convince the fence sitters.

I’m optimistic for the first time in awhile.

[Orphia Nay]

Oxford vaccine stimulates broad antibody and T cell functions

From Oxford:
https://www.ox.ac.uk/news/2020-12-17...cell-functions

They're moving to a 2-stage delivery of the vaccine, because giving a booster dose produces stronger antibody responses.

They've also released 2 papers in Nature Medicine about the antibody and T cell response.

[Orphia Nay]

And to lighten things up a little:

If Every Country Had A Vaccine

https://www.youtube.com/watch?v=fcD78s9EqGQ

[Lplus]

Originally Posted by Orphia Nay

Oxford vaccine stimulates broad antibody and T cell functions

From Oxford:
https://www.ox.ac.uk/news/2020-12-17...cell-functions

They're moving to a 2-stage delivery of the vaccine, because giving a booster dose produces stronger antibody responses.

They've also released 2 papers in Nature Medicine about the antibody and T cell response.

That's further information on the st 1 and 2 trials. The two stage vaccination was used for the stage 3 trials. The UK regulator is presently looking at the data from the SA, Brazil and UK st 3 trials. The US phase of those trials is limping along slowly for some reason.

[Rolfe]

That's interesting about the unblinding and the vaccination of the placebo arm. The friend I'm going to spend Christmas and New Year with (we're forming an extended household, as we're both single-person households, so we can basically stay together as long as we like) was in a vaccine trial and doesn't know if she was vaccinated or not. I wonder if she'll find out before Christmas?

I'm going to spend Christmas in her house, and then we're going to switch to my place for New Year and I think she plans to stay until about the 4th. Since she's the one who lives in a high-prevalence area and has been going to the shops and to church (I'm in a low-prevalence area and am avoiding other people as much as possible) I'd be quite pleased to know she was vaccinated.

[marting]

So much for the notion that there's a large percentage of false positives in the case counts. Some people have even claimed 50%.

The double blinded, placebo, vaccine trials put a lower limit on it.

They have come back with efficacy of about 95%. Which means that no more than 5% of the cases could be false positives and even that would require the vaccine be 100% effective.

[sphenisc]

Originally Posted by marting

So much for the notion that there's a large percentage of false positives in the case counts. Some people have even claimed 50%.

The double blinded, placebo, vaccine trials put a lower limit on it.

They have come back with efficacy of about 95%. Which means that no more than 5% of the cases could be false positives and even that would require the vaccine be 100% effective.

Not following that. Can you explain the reasoning. Thanks.

[Meridian]

It seems (BBC article here; more specific Guardian article here) that in parts of the UK there's a new variant that seems to spread faster ("up to 70% faster" in the BBC article). I wonder whether something similar might be happening elsewhere, in particular in Germany: the overall numbers were pretty static for November, and then started growing for no (to me, but what do I know?) obvious reason around the start of December. I don't believe any restrictions were loosened.

Any pointers to good information on this welcome!

[marting]

Originally Posted by sphenisc

Not following that. Can you explain the reasoning. Thanks.

Take an example where among the 10's of thousands that were "vaccinated," half with a placebo, half with actual. Let's say over the course of 3 months 4 people in the vaccinated group test positive but 200 people in the placebo group test positive giving the 95% efficacy rate, that strongly implies that false positives are below 5% of all positives else the vaccinated group would have shown higher case counts. And were the 4 people that tested positive in the vaccinated group false positives, that would require the vaccine be essentially 100% effective. Neither the docs, testers, nor the people in the study knew whether the vaccination was placebo.

[marting]

Originally Posted by Meridian

It seems (BBC article here; more specific Guardian article here) that in parts of the UK there's a new variant that seems to spread faster ("up to 70% faster" in the BBC article). I wonder whether something similar might be happening elsewhere, in particular in Germany: the overall numbers were pretty static for November, and then started growing for no (to me, but what do I know?) obvious reason around the start of December. I don't believe any restrictions were loosened.

Any pointers to good information on this welcome!

Hard to say what "70%" faster means. Are they saying the R is 70% higher? Or is it spreading such that in two weeks the number of new variant case increases was 70% more than the old? Without specifics it's pretty hard to tell anything other than it seems more infectious.

To some degree this is normal. Bugs want to evolve to be more "fit" and that means spreads more easily. "Fitness" for the bug is not positively correlated to how serious/fatal it is. That doesn't help it spread through evolutionary pressure. We've already seen one variant that took over back in the Spring pretty much everywhere.