Spreads so easily......

[audreyh1]

The source turned out to be likely the mother of one of her co-workers who passed it onto him before she took seriously ill and died. The Perspex screens around the desks and distance between the workers obviously did not help during the course of 8 hour days. No A/C, and in the winter the only window in the office was opened at the top only so obviously not enough air changes.

Thanks for the followup. Everyone wants to know who got infected first! So sad about the coworkers mother!

 

[audreyh1]

Yes, absolutely.

While everyone is running around with their hair on fire yelling about "test accuracy" and "gold standard", they forgot to note two very important, I'd say "critical" facts about what we want to know in this situation.

We want to know if a person is 1) shedding high quantities, 2) right now, as the person walks in.

Let's see how a PCR test holds-up. One fact is that people who get over the disease show PCR positive for a long time (a week or two) after they are no longer shedding 'live' virus. So that test would be a false positive for our purposes. Then there's the time lag. 3 days is common, and often it's longer. If you look at the acquisition Ct curve, you see it goes from nothing to it's 'max' value in 2 days. That means a negative three days ago says nothing about viral shedding today.

The lateral flow assay technology is close to 100% accurate at finding people who are shedding large amounts of virus, and it tells you in 15 minutes. To me, in the eyes of public health, it's a crime that this technology has been hampered.

Wow, thanks for the details!

Yes, it’s crazy that this isn’t being used right now!

 

[Montecfo]

Well I have to admit I was wrong. On 2/6 after UNC beat Duke in basketball about 1000 UNC students took to the streets in Chapel Hill for a celebration party. No social distancing and not many masks. I and many other residents of Chapel Hill were concerned this was a super spreader event and would lead to a spike in cases. Has not happened. Cases in my county are dropping, the positivity rate in my county is only 1.5% and as of yesterday there were only 15 positive on campus. So I guess a bunch of college age people partying outside for about an hour is not a super spreader event after all.

The super bowl was widely derided as a super spreader event with thousands of unmasked un-distanced fans in Tampa celebrating in the streets. But the predicted spike in cases has not only not happened, cases have continued to decline.

I assume the reasons are the same ones driving the decline most places.

 

[harllee]

Talking about these outdoor celebrations not being super spreaders makes it really clear that the virus just does not easily spread outdoors. I wonder if there have been any specific examples of where the virus spread can be traced to an outdoor event?

 

[audreyh1]

People recall the Rose Garden super spreader event in late Sept 2020 where people were sitting side by side, shoulder to shoulder, very few masked, and lots of hugging and hand shaking beforehand. But it turned out that those infected had also attended two indoors receptions immediately afterwards, so it certainly could be that the spreading occurred indoors as many concluded. Still - talking loudly and hugging maskless even outdoors seems like you could spread it.

At one point many months in, the CDC indicated someone who ate at a restaurant was twice as likely to catch Covid, and it seemed that outdoors was just as likely but it wasn’t clear. Indoor dining wasn’t very common at the time.

We do know that New Orleans Mardi Gras in 2020 was a huge super spreader event initiating a large first spike for LA, and a lot of Mardi Gras activity is crowds (many intoxicated) celebrating outdoors in close proximity for long periods.

 

[Aerides]

Talking about these outdoor celebrations not being super spreaders makes it really clear that the virus just does not easily spread outdoors. I wonder if there have been any specific examples of where the virus spread can be traced to an outdoor event?

The US has never had robust contact tracing, so we don't know - about any of these events. To me the obvious is yes, you can get sick outdoors. No wind? Sheltered on a patio? Talking for 20 mins with no masks in close proximity? Sure, might as well be indoors.

Other than "200 ppl were here, now 30 are sick, therefore..." - correlation, not causation. Of course, if 10 ppl were sick going into that event, it's gonna raise enough numbers to notice, but if only 1 or 2 were, maybe not so much.

 

[harllee]

The Rose Garden event and Mardi Gras and the Sturgis motorcycle rally were all super spreader events that had both indoor and outdoor get togethers and involved people of all ages who were in contact for several hours/days. The UNC student basketball celebration was all outdoors and only lasted about an hour. And of course it mainly involved young people 18-22 years old. I wish we had better tracing in the US so we could identify the true super spreader events and concentrate our efforts in eliminating events that are truly super spreaders.

 

[audreyh1]

Since in the past few months most people have gotten Covid from small family gatherings, I’m not sure how important it is any more. With few exceptions, large indoor gatherings are not allowed and smart people avoid them. The few that refuse aren’t going to be stopped anyway. I think the current focus on getting as many people as possible vaccinated (by health risk group) while continuing precautions is a good approach. People know they aren’t supposed to gather, in large groups or small non household groups, especially without precautions. How you can stop the determined few? Best to vaccinate the vulnerable ASAP.

 

[USGrant1962]

A new study suggests that only 10-13% of household members catch Covid when exposed to a case in the household. That makes sense from what I've heard - I know many people where one person had it and, contrary to conventional wisdom, the whole household did not get infected. And we've been hearing that story from day 1.

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2776908?resultClick=1

One of many logical errors surfacing under Covid is that because many people that get Covid got it from a housemate, all housemates are likely to catch it.

 

[sengsational]

The paper didn't quite say that this small percentage "catch Covid", it said "catch Covid and seek treatment" It's no news that most people just suffer through symptoms and recover, especially kids and younger, healthier people.

In addition, because testing of household members was driven by care-seeking behavior, it is likely that we did not observe all infections that occurred in the households.

 

[Montecfo]

UK variant stopped by Pfizer vax in real world

A peer-reviewed Israeli study just completed is a treasure trove of information about the Pfizer/bioNtech vaccine.

The vaccine was found to be just as effective in the real world (94%) as it was in the controlled studies, and showed real world efficacy across all age groups and subjects with various medical histories.

And it was effective against the UK variant.

https://www.theguardian.com/world/2021/feb/25/pfizer-covid-vaccine-94-effective-study-of-12m-people-finds

 

[Born2BRetd]

A new study suggests that only 10-13% of household members catch Covid when exposed to a case in the household. That makes sense from what I've heard - I know many people where one person had it and, contrary to conventional wisdom, the whole household did not get infected. And we've been hearing that story from day 1.

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2776908?resultClick=1

One of many logical errors surfacing under Covid is that because many people that get Covid got it from a housemate, all housemates are likely to catch it.

I feel it's a bit like Russian Roulette. My cousin's 20 year old daughter had a severe case and was in the hospital for five days but no one else in her family tested positive. On the other hand, we have some friends and everyone in their household and their extended family caught it including a 45 year old brother who has now been in ICU for over 50 days.

 

[Born2BRetd]

Also, my Uncle knows a couple that went to Guadalajara for Christmas. Both husband and wife caught it. The wife died and the husband is still in ICU.

I think there are so many variables: genetic factors, true exposure vs no exposure, Covid strain, asymptomatic vs symptomatic, etc.

 

[Lsbcal]

A peer-reviewed Israeli study just completed is a treasure trove of information about the Pfizer/bioNtech vaccine.

The vaccine was found to be just as effective in the real world (94%) as it was in the controlled studies, and showed real world efficacy across all age groups and subjects with various medical histories.

And it was effective against the UK variant.

https://www.theguardian.com/world/2021/feb/25/pfizer-covid-vaccine-94-effective-study-of-12m-people-finds

I wondered about that "red" line above and had previously heard the same thing from DW. But I thought Pfizer's controlled study was done in the real world with something like 30k people in the USA. Wasn't that just as good as the Israeli news?

 

[Leo1277]

I wondered about that "red" line above and had previously heard the same thing from DW. But I thought Pfizer's controlled study was done in the real world with something like 30k people in the USA. Wasn't that just as good as the Israeli news?

It's a good point, as these studies with 30k people try to be as realistic as possible. But further down in the article, among various reasons, it lists this as the most important aspect:

“We were surprised because we expected that in the real-world setting, where cold chain is not maintained perfectly and the population is older and sicker, that you will not get as good results as you got in the controlled clinical trials,” the senior study author, Ran Balicer, told Reuters. “But we did and the vaccine worked as well in the real world.”

 

[Montecfo]

JNJ single shot vax approved

Johnson & Johnson's single shot covid vaccine has been approved by the FDA for emergency use.

US distribution of 4million doses to begin next week.

A fresh new weapon against Covid.

https://www.cnbc.com/2021/02/27/fda-approves-jjs-single-shot-covid-vaccine-for-emergency-use.html

 

[Sunset]

Here is what I don't understand about the Covid vaccine.

I've repeatedly heard on the news that after a person gets vaccinated, they still need to wear a mask as they might catch Covid and spread it, even though they themselves won't be too sick.

I don't recall any such warnings about the Polio shot or any other vaccine. Nobody says I can still get Polio, and spread it, but I won't get too crippled or die from it.

So why the difference ?
Is it because the Moderna and Pfizer vaccines are a different mechanism than old vaccines , and will this not apply to the J&J vaccine as it is made the old way ?

 

[Montecfo]

Sunset, lots of vaccines do not generate a "sterilizing" response as the polio vaccine can.

But on the coronavirus vaccines we really do not know to what extent reinfection is prevented, as opposed to simply reducing symptomatic infections.

As I understand it, the trials did not attempt to determine this answer as they were focused on immune response. But so far few documented reinfections have occurred, so there is hope. But more study us needed.

 

[Buckeye]

People recall the Rose Garden super spreader event in late Sept 2020 where people were sitting side by side, shoulder to shoulder, very few masked, and lots of hugging and hand shaking beforehand. But it turned out that those infected had also attended two indoors receptions immediately afterwards, so it certainly could be that the spreading occurred indoors as many concluded. Still - talking loudly and hugging maskless even outdoors seems like you could spread it.

At one point many months in, the CDC indicated someone who ate at a restaurant was twice as likely to catch Covid, and it seemed that outdoors was just as likely but it wasn’t clear. Indoor dining wasn’t very common at the time.

We do know that New Orleans Mardi Gras in 2020 was a huge super spreader event initiating a large first spike for LA, and a lot of Mardi Gras activity is crowds (many intoxicated) celebrating outdoors in close proximity for long periods.

We were in some very tightly packed bars in NOLA in January 2020. There were lots of people packed together in the street but it was also packed in the little bars/music venues along Bourbon Street and the surrounding neighborhood. I'd guess the super spreading took place at the indoor venues.

 

[cathy63]

Here is what I don't understand about the Covid vaccine.

I've repeatedly heard on the news that after a person gets vaccinated, they still need to wear a mask as they might catch Covid and spread it, even though they themselves won't be too sick.

I don't recall any such warnings about the Polio shot or any other vaccine. Nobody says I can still get Polio, and spread it, but I won't get too crippled or die from it.

So why the difference ?
Is it because the Moderna and Pfizer vaccines are a different mechanism than old vaccines , and will this not apply to the J&J vaccine as it is made the old way ?

As I understand it, the theory is that the immune response in the nasopharyngeal cells where the virus first starts multiplying in most people is not as effective as it is in other areas of the body. So theoretically, you could have an infection in your nose, test positive for Covid-19 with the swab test, and continue to breathe out viral particles that infect other people. But as the virus tried to attack you in other ways, your vaccinated immune system would fight it off and the infection would never really make you sick.

Polio is primarily transmitted by contact with fecal matter or droplets, so you can't really carry around an infection that's not making you sick, and even if you did have some virus in your nose, breathing it out wouldn't make other people sick.

I'm not a virologist, so this is just what I've gleaned from reading about vaccines and how they work. It's quite possible I've got something wrong or oversimplified things.

 

[audreyh1]

Here is what I don't understand about the Covid vaccine.

I've repeatedly heard on the news that after a person gets vaccinated, they still need to wear a mask as they might catch Covid and spread it, even though they themselves won't be too sick.

I don't recall any such warnings about the Polio shot or any other vaccine. Nobody says I can still get Polio, and spread it, but I won't get too crippled or die from it.

So why the difference ?
Is it because the Moderna and Pfizer vaccines are a different mechanism than old vaccines , and will this not apply to the J&J vaccine as it is made the old way ?

Unfortunately, these don’t seem to be sterilizing vaccines, and it wasn’t expected that they would be. It’s not due to the mRNA technology - all the Covid vaccines appear to not be sterilizing vaccines. Is seems to have more to do with the virus itself.

It’s going to take time to learn how much transmission is reduced, how long the immunity lasts, etc. The phase 3 trials only looked at symptomatic infections. They weren’t testing subjects for Covid weekly or anything like that.

 

[twaddle]

It’s going to take time to learn how much transmission is reduced...

If somebody who is vaccinated unknowingly transmitted the virus, that would mean the vaccinated person had an asymptomatic infection, correct?

The recent study from Israel found that after the second dose of the Pfizer vaccine, asymptomatic infection risk was reduced by 90%.

Obviously even more data would be better, and the "in the wild" study had to rely on reported symptoms, so not a perfect experiment, but am I the only one optimistic about this?

OTOH, what sort of data do we have that supports the notion of transmission by the vaccinated?

 

[Montecfo]

If somebody who is vaccinated unknowingly transmitted the virus, that would mean the vaccinated person had an asymptomatic infection, correct?

The recent study from Israel found that after the second dose of the Pfizer vaccine, asymptomatic infection risk was reduced by 90%.

Obviously even more data would be better, and the "in the wild" study had to rely on reported symptoms, so not a perfect experiment, but am I the only one optimistic about this?

OTOH, what sort of data do we have that supports the notion of transmission by the vaccinated?

I am also optimistic about it.

Frankly, the more info we get about these vaccines, the better it gets. Efficacy is better than hoped, side effects minimal, and there several data points that say immunity could be long lasting. The vaccines appear to have efficacy against variants in all the cases I have seen. Tweaking the vaccines to address variants more effectively does not seem to be a big deal. And now we even have a one shot vaccine. Also recently, we learned the Pfizer vaccine does not require the very low storage temperatures as was first believed. This makes it easier to distribute more widely.

In my opinion, these vaccines arrived more quickly and are more effective than all but the most optimistic among us could have imagined.

 

[Sunset]

Thanks to all that answered my question about the vaccine.
Now I know there are sterilizing ones (which stop the virus from reproduction) and others.

According to the NY Times (and another site but quite unknown):
"....The polio vaccine developed by Dr. Jonas Salk, which does not provide sterilizing immunity, resulted in the rapid elimination of polio in the United States beginning in the 1950s....."
https://www.nytimes.com/2021/02/23/opinion/covid-vaccines-transmission.html

Startling was reading the information from the CDC , that perhaps all old folks are no longer protected from Polio
"It is not known how long people who received IPV will be immune to poliovirus, but they are most likely protected for many years after a complete series of IPV."

https://www.cdc.gov/vaccines/vpd/polio/hcp/effectiveness-duration-protection.html

 

[Chuckanut]

Thanks to all that answered my question about the vaccine.
Now I know there are sterilizing ones (which stop the virus from reproduction) and others.

According to the NY Times (and another site but quite unknown):
"....The polio vaccine developed by Dr. Jonas Salk, which does not provide sterilizing immunity, resulted in the rapid elimination of polio in the United States beginning in the 1950s....."

It was the Sabin oral vaccine that prevented transmission of the polio virus.

https://www.cincinnati.com/story/ne...competed-for-safest-polio-vaccine/1140590001/