Spreads so easily......

[audreyh1]

Audrey--this makes sense to me. So all those people who got tested right before visiting family at Christmas were just fooling themselves and their families. They could still be infectious and give the virus to their families. Which is one of the reasons we are in this terrible spike.

Exactly. Well before Christmas the White House had demonstrated quite clearly how daily testing did not prevent a significant outbreak when folks aren't taking other precautions. It simply does not work unless timely isolation is also used and gatherings outside a strict bubble are avoided.

Yes, fooling themselves is a great description.

 

[Buckeye]

They absolutely would. We’re talking about a few RNA base pairs different. Much less different than the annual flu shot. There are two proteins in the flu virus capsule to which we make antibodies: hemagglutinin and neuraminidase. Hence the designation H1N1 etc. They guess which one. And the process takes many months. mRNA vaccine technology is much quicker.

The process for both the flu vaccine and a changing COVID vaccine does not change. The only thing that changes is the slightly but significantly different viral component, the two proteins, in the case of the flu, the mRNA in the case of coronavirus.

With mRNA vaccine some of the cells in our body are instructed to produce spike protein. Our body recognizes it as a foreign protein, “thinks” it is a virus and develops an immune response. But the rest of the viral RNA isn’t there so there is no actual virus. A second exposure, a second dose, boosts that immune response. But because there is no replicating virus, only a small amount of the protein is made, and our cells don’t get destroyed, and we don’t get disease.

Thank you for the explanation. Very interesting!

 

[Leo1277]

Seems like testing negative several times before testing positive is quite common. You have to have enough virus to be detected by whatever test. It shows yet again that preemptive testing does not work and can’t be used for real-time screening. Just because you tested negative today doesn’t mean you weren’t infected 2 or 3 days ago, and might be infectious tomorrow.

Regarding the vaccines, various folks are talking about first evidence that while the vaccination may protect (most) vaccinated folks from getting ill, it does not prevent them from getting infected, and potentially infecting others. That would be really unfortunate, since it would just increase the number of asymptomatic spreaders, and would also mean that vaccinations do not primarily help reduce the prevalence of the virus. So un-vaccinated folks and those unlucky ones for whom the vaccination does not produce immunity will continue to be in danger. Add to this that we don't know how long immunity (due to exposure or vaccination) lasts, and we still have an uphill climb.

 

[CardsFan]

Regarding the vaccines, various folks are talking about first evidence that while the vaccination may protect (most) vaccinated folks from getting ill, it does not prevent them from getting infected, and potentially infecting others. That would be really unfortunate, since it would just increase the number of asymptomatic spreaders, and would also mean that vaccinations do not primarily help reduce the prevalence of the virus. So un-vaccinated folks and those unlucky ones for whom the vaccination does not produce immunity will continue to be in danger. Add to this that we don't know how long immunity (due to exposure or vaccination) lasts, and we still have an uphill climb.

Can you provide a little back-up to the bolded comment above? Everything I have read says "we just don't know, because it was not tested"

 

[retire-early]

Seems like testing negative several times before testing positive is quite common. You have to have enough virus to be detected by whatever test. It shows yet again that preemptive testing does not work and can’t be used for real-time screening. Just because you tested negative today doesn’t mean you weren’t infected 2 or 3 days ago, and might be infectious tomorrow.

With all tests, the limit has to be set somewhere.

That's say they set the limit at 50.
So someone with 49 is "negative" and someone with 51 is "positive".
And yet, most logical people would say that both individuals are infected.

With some of the reporting I have read from Taiwan, their CDC briefing actually tells the level when discussing cases.

.

 

[Leo1277]

Originally Posted by Leo1277 Regarding the vaccines, various folks are talking about first evidence that while the vaccination may protect (most) vaccinated folks from getting ill, it does not prevent them from getting infected, and potentially infecting others.

Can you provide a little back-up to the bolded comment above? Everything I have read says "we just don't know, because it was not tested"

Thanks for being careful about this question, it is a sensitive topic and we are only learning very slowly and should be mindful about this. One of the places where I read this was here: https://www.cnn.com/2021/01/14/health/covid-immunity-antibodies-intl/index.html From that article:

<snip>
But early insight from the next stage of the study shows that some people with existing immunity carry high levels of virus and could transmit the virus to others.
Hopkins highlighted this during an interview with the BBC's Today program on Thursday.
"We found people with very high amounts of virus in their nose and throat swabs, that would easily be in the range which would cause levels of transmission to other individuals."
Hopkins stressed that people who had previously caught Covid-19 still needed to obey social distancing rules to avoid transmitting the disease.
<snip>
"The concerning finding is that some people who have Covid antibodies appear to still be able to carry the coronavirus and could spread it to others. This means that the vast majority of the population will either need to have natural immunity or have been immunised for us to fully lift restrictions on our lives,"
<snip>

 

[CardsFan]

Thanks for being careful about this question, it is a sensitive topic and we are only learning very slowly and should be mindful about this. One of the places where I read this was here: https://www.cnn.com/2021/01/14/health/covid-immunity-antibodies-intl/index.html From that article:

OK. But the referenced study had no content about vaccinated people, only those that had contracted the virus, where as your original quote talked specifically about vaccinations.

There could/may be a difference.

 

[harllee]

Now that more people are being vaccinated can't the scientists start tracking the vaccinated people to find out whether or not they are infecting people. It seems like tracking could answer this question pretty quickly.

 

[Leo1277]

OK. But the referenced study had no content about vaccinated people, only those that had contracted the virus, where as your original quote talked specifically about vaccinations.There could/may be a difference.

You are right, and since there aren't so many vaccinated people yet, it may take a while before there is enough good statistics about them. The study talks about people with antibodies, and from that one may think whether they got their antibodies through vaccination or "natural" exposure would be similar.

As I understand, it is common in various other diseases that the reduction rate for serious disease through vaccination is often higher than the reduction rate for spreading the same disease. But that part I must have read a long time ago and I don't have a reference ready - any epidemiologists or infections disease experts among us who can comment?

 

[Leo1277]

Now that more people are being vaccinated can't the scientists start tracking the vaccinated people to find out whether or not they are infecting people. It seems like tracking could answer this question pretty quickly.

Yes; except that we should not expect widespread tracking, considering how well this has worked for preventive contact tracing purposes so far. But it may be particularly useful to continue to follow the original 30,000 (?) volunteers for each of the vaccines and study their antibody status over time, whether their immunity decreases with time and they continue to not get infected, etc. And since theses volunteers have been part of a formal system and are used to formal self-observation, they may be easier to track for all kinds of things including whether they believe they infected anybody. I hope, but expect, that the vaccine companies are doing that.

 

[tmm99]

With all tests, the limit has to be set somewhere.

That's say they set the limit at 50.
So someone with 49 is "negative" and someone with 51 is "positive".
And yet, most logical people would say that both individuals are infected.

With some of the reporting I have read from Taiwan, their CDC briefing actually tells the level when discussing cases.

.

An interesting point to remember.

 

[audreyh1]

With all tests, the limit has to be set somewhere.

That's say they set the limit at 50.
So someone with 49 is "negative" and someone with 51 is "positive".
And yet, most logical people would say that both individuals are infected.

With some of the reporting I have read from Taiwan, their CDC briefing actually tells the level when discussing cases.

.

I’m not sure that’s how it works.

 

[Alan]

Now that more people are being vaccinated can't the scientists start tracking the vaccinated people to find out whether or not they are infecting people. It seems like tracking could answer this question pretty quickly.

This is happening in the UK. Thousands of hospital workers have been vaccinated and they continue to be tested twice a week as part of their job. By end of February it should be known if any of those vaccinated become carriers without getting sick.

 

[harllee]

This is happening in the UK. Thousands of hospital workers have been vaccinated and they continue to be tested twice a week as part of their job. By end of February it should be known if any of those vaccinated become carriers without getting sick.

Thanks Alan, this will be very important info to know--please keep us updated

 

[sengsational]

It would seem that all the "negatives-which-are-actually-positive" would argue for a more sensitive test. True enough, but then we might get into more false positives. Let's hope the vaccine makes this issue an interesting footnote in history - sooner rather than later. YMMV

Many of us here are familiar with doing a calculation with high precision, then rounding the result to three significant figures. In my statics class, where 10 problems were the semester grade, if you answered 23.126 instead of 23.13, you dropped a letter grade.

It seems that calling for more precision in test technology isn't the answer, because how and when the sample is taken is critical. It's probably the weak link in preventing transmission. In other words, taking one sample from one body site on one day and doing a "precision" test on it (the gold standard is the PCR test) isn't as effective as doing two or five "less precise" tests (that return results more quickly and cost a tiny fraction of the PCR test) that hit various sites that harbor virus, and sites likely to allow virus to exit in a way another person can acquire it. But even testing multiple sites, and getting results in a few minutes, the determination will be imperfect. But the test itself is not to blame, as much as our inability to put a swab in the "right place".

 

[tmm99]

This is happening in the UK. Thousands of hospital workers have been vaccinated and they continue to be tested twice a week as part of their job. By end of February it should be known if any of those vaccinated become carriers without getting sick.

Good info. Thanks!

 

[Aerides]

Most of the variability in testing appears to be in human actions, not the actual test itself: Taken at the wrong time, either too soon after infection, or too long, would result in a "false" negative.

It seems the sweet spot window is somewhere between about 48 hours after exposure, until 3-4 days into the start of symptoms. I know if I thought there was a good chance I had it, I'd find ways to get tested several times. I wouldn't get one negative and be "welp I'm good" until I got at least 3 negatives over 3 days, something like that. This is why packs of cheap tests for home use would be great. Pack-of-5, $25, 80% accuracy? I'd take that, but it's not happening....

 

[Rosedala]

Most of the variability in testing appears to be in human actions, not the actual test itself: Taken at the wrong time, either too soon after infection, or too long, would result in a "false" negative.

It seems the sweet spot window is somewhere between about 48 hours after exposure, until 3-4 days into the start of symptoms. I know if I thought there was a good chance I had it, I'd find ways to get tested several times. I wouldn't get one negative and be "welp I'm good" until I got at least 3 negatives over 3 days, something like that. This is why packs of cheap tests for home use would be great. Pack-of-5, $25, 80% accuracy? I'd take that, but it's not happening....

Hi Aerides, you're smart in applying the 3-time method when negative before you happily jump up and down, lol!

 

[travelover]

This is troubling.

Like a speeding car whose brake lines have been cut, the coronavirus variant first spotted in Britain is spreading at an alarming rate and isn’t responding to established ways of slowing the pandemic, according to Danish scientists who have one of the world’s best views into the new, more contagious strain.
Cases involving the variant are increasing 70 percent a week in Denmark, despite a strict lockdown, according to Denmark’s State Serum Institute, a government agency that tracks diseases and advises health policy.

https://www.washingtonpost.com/worl...faf420-5453-11eb-acc5-92d2819a1ccb_story.html

 

[retire-early]

This is troubling.

https://www.washingtonpost.com/worl...faf420-5453-11eb-acc5-92d2819a1ccb_story.html

I thought we had enough protective gear, but I am thinking I may need to buy some more. SIGH.

 

[Spudd]

What I find really amazing is comparing the Covid stats to this year's flu stats. For the past week, in the US, there were 1159 cases of flu. Last year, same week, there were 17,407 cases. That means this year's flu incidence is less than 7% of last year's.

Last week, cases of Covid were 1.3 million.

Presumably our intense social distancing/masking/hygiene has been the main reason the flu has decreased so much. Yet despite all that, there are still 1.3 million cases of Covid in a week. Imagine if we weren't doing anything? I feel like everyone would have caught it by now!

 

[harllee]

What I find really amazing is comparing the Covid stats to this year's flu stats. For the past week, in the US, there were 1159 cases of flu. Last year, same week, there were 17,407 cases. That means this year's flu incidence is less than 7% of last year's.

Last week, cases of Covid were 1.3 million.

Presumably our intense social distancing/masking/hygiene has been the main reason the flu has decreased so much. Yet despite all that, there are still 1.3 million cases of Covid in a week. Imagine if we weren't doing anything? I feel like everyone would have caught it by now!

It seems to me that the flu is not very transmissible as compared to Covid. Covid appears to be much much more easy to catch than the flu is. Scary isn't it.

 

[ivinsfan]

It seems to me that the flu is not very transmissible as compared to Covid. Covid appears to be much much more easy to catch than the flu is. Scary isn't it.

Well we do have widely available flu vaccines and some us have some natural antibodies from previous bouts of the same strain of flu. With Covid we don't have any of that going for us.

If covid of some type is around in 10-20 years ( fair chance it will be) we might get more of an idea about transmissibility. Right now it certainly does appear to be more contagious then flu. I hope we can do some things to make that change.

 

[Buckeye]

I also wonder if the flu has as many asymptomatic spreaders as does COVID. I thought the last statistic I saw was that 47 percent of the people who are spreading COVID are asymptomatic. I have no idea what the number is for the flu.

 

[USGrant1962]

I also wonder if the flu has as many asymptomatic spreaders as does COVID. I thought the last statistic I saw was that 47 percent of the people who are spreading COVID are asymptomatic. I have no idea what the number is for the flu.

Plus some Covid diagnoses are without tests. A portion of reported Covid cases might actually be flu. I have no idea what that fraction might be.