Spreads so easily......

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Sunset said:
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
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But polio had potentially very bad outcomes for the young, while much older folks did not have bad disease. So immunity wasn’t that important in the elderly. Chlorinated pools was another protection.

P.S. this article, which had already been linked somewhere in this forum, does a good job of explaining how these vaccines are effective and what we know so far. It also compares other common vaccines and their effectiveness. https://www.livescience.com/covid-19-vaccine-efficacy-explained.html
 
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I have followed all directions from the authorities and will continue to do so.

Still, it is frustrating to see the confusion. It is clear to me that the science on these viruses is not fully understood. It is also clear to me that some public authorities are getting a dopamine hit from the control, and will have a let down when it is over.

I think that's why we may be seeing split in the predictions for the next 8 weeks.

We will soon find out if we're going to drift down, stay stable or spike. The numbers will play out.
 
JoeWras said:
I It is also clear to me that some public authorities are getting a dopamine hit from the control, and will have a let down when it is over.
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Could that be why my state and a number of other Western states have to first get approval for the J&J vaccine from their group of experts? I am leaning in that direction.

As mentioned earlier, for some people, corona virus has become their shtick - something that gives them attention, affirmation and power. They don't want to give that up quite yet.

OTOH, When I hear people say that because they have their two shots (or sometimes their first of two shows, they can now do whatever they wish with whomever they wish, I get concerned. Nobody is bullet proof when it comes to Covid. Like my old grandpappy used to say when I went out with an attractive young lady - "Have fun, but don't go wild.
 
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I watched a Nova documentary last week and on the segment on herd immunity they used a formula different to the one I had seen.

Herd immunity = 1-1/R0 is the one I was familiar with so with R0=3 then herd immunity would be 67% of population, so with faster spreading variants, R0>3, then herd immunity % goes up.

The formula used on the program was (1-1/R0)/Efficacy so if the vaccines are 100% effective then herd immunity for R0=3 remains at 67%, but with an effectiveness of 90% then herd immunity rises to 74%.

They also explained the difference between efficacy and effectiveness. Efficacy being what was measured during the trials with the selected groups of volunteers, who have varying ages, and effectiveness being what is measured in real life which may likely include a much older and sicker population receiving the vaccine(s) than the one used in the trials.
 
Alan said:
I watched a Nova documentary last week and on the segment on herd immunity they used a formula different to the one I had seen.

Herd immunity = 1-1/R0 is the one I was familiar with so with R0=3 then herd immunity would be 67% of population, so with faster spreading variants, R0>3, then herd immunity % goes up.

The formula used on the program was (1-1/R0)/Efficacy so if the vaccines are 100% effective then herd immunity for R0=3 remains at 67%, but with an effectiveness of 90% then herd immunity rises to 74%.

They also explained the difference between efficacy and effectiveness. Efficacy being what was measured during the trials with the selected groups of volunteers, who have varying ages, and effectiveness being what is measured in real life which may likely include a much older and sicker population receiving the vaccine(s) than the one used in the trials.
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The latest estimates of Ro that I have seen are 2.1 to 2.4 (based on Korean data) https://europepmc.org/article/MED/33612125

and 3.3 (based on Danish data) https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0247021

If it is 3.0, that does not necessarily mean that you need to vaccinate 74% of the population, as some will have immunity from a prior infection.

It has been estimated that perhaps 33% of the population of the US has been infected already. https://www.npr.org/sections/health...the-pandemic-is-10-times-worse-than-you-think

If infection and recovery conveys immunity comparable to the vaccine (and only 57 people around the world are known to have been infected twice https://www.marketwatch.com/story/o...medical-experts-are-on-high-alert-11613743994 ), that would mean you only need to reach another 40% or so with vaccines before herd immunity starts to develop.

Although, to be sure, there will be some duplication in that people who may already have been infected may be part of the group getting the vaccine.
 
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Alan said:
<snip>
The formula used on the program was (1-1/R0)/Efficacy so if the vaccines are 100% effective then herd immunity for R0=3 remains at 67%, but with an effectiveness of 90% then herd immunity rises to 74%.
<snip>
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This is the mathematically correct formula to calculate the needed vaccination fraction. But we should always be clear that it only describes reality if many simplifications are assumed. First it assumes that the population, the R0, and the immunity levels are uniform in location and time. But that is not really the case, rather you could have local outbreaks where R0 changes (due to distancing behavior, for example during certain religious services; new variants, for example it is believed that several of the newer ones have higher R0; higher or lower susceptibility of the population, for example from what we see so far children are not only less likely to get severe cases but less like to get infected at all)

I like to view the situation more like fire danger in forests in western states: the danger may well be extreme, but if there is no trigger somewhere, there is no fire. But even if the danger is not extreme, some careless campfire somewhere can start a big fire. And then you need to bring to bear firebreaks (social distancing for trees), local water (masks for trees) and whatever else is in the arsenal of firefighters, or ideally, rain as water from above (the virus accidentally mutating to something less dangerous, which is likely what happened with the 1918 flu).
Gumby said:
The latest estimates of Ro that I have seen are 2.1 to 2.4 (based on Korean data) https://europepmc.org/article/MED/33612125 and 3.3 (based on Danish data) https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0247021 If it is 3.0, that does not necessarily mean that you need to vaccinate 74% of the population, as some will have immunity from a prior infection.
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Indeed the 74% would be needed to keep the "average" fire danger low, and it can be either due to previous infection, or due to vaccine. But to avoid dangers in more dangerous pockets, you need more than that, and you need a rapid response system (fire department) to move in and deal with local outbreaks. Also, the Danish data are likely higher because there they are currently seeing the UK variant, which is more infectious. Overall, the more infectious variants propagate better, so what we are seeing is an overall upwards creep of R0.
Gumby said:
It has been estimated that perhaps 33% of the population of the US has been infected already. https://www.npr.org/sections/health...the-pandemic-is-10-times-worse-than-you-think

If infection and recovery conveys immunity comparable to the vaccine (and only 57 people around the world are known to have been infected twice https://www.marketwatch.com/story/o...medical-experts-are-on-high-alert-11613743994 ), that would mean you only need to reach another 40% or so with vaccines before herd immunity starts to develop.

Although, to be sure, there will be some duplication in that people who may already have been infected may be part of the group getting the vaccine.
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Indeed. If say 1/3 of the population is already protected and you want to achieve 3/4 immunity by randomly vaccinating a fraction x of the population, then you need to have 1/3 + 2/3 x = 3/4. If my morning coffee has kicked in sufficiently already, this means x=5/8 or about 62%. Still a hill to climb.

And then the problem is that if this coronavirus behaves like the four others that cause common cold, then immunity doesn't last very long. So get ready for annual Covid-19 shots.
 
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twaddle said:
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?
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Studies out of England confirmed the same last week. By the date they said they would know back the first week in January.
The media should have been saying we don't know yet - not that it probably wouldn't.

https://www.reuters.com/article/us-...mission-after-one-dose-uk-study-idUSKBN2AQ17L
 
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"Functional" herd immunity

It seems to me we are beginning to achieve what I will call "functional" herd immunity. By vaccinating the people at highest risk first, and with a meaningful number having immunity due to exposures to Covid or other coronaviruses, hospitalizations are on what is probably a steady path lower.

And as vaccinations accelerate, with the JNJ vaccine coming on and kinks begining to work themselves out, more and more people will be immune.

Experts have talked about this new trajectory, not using these words but I think this is what is happening. Since most cases are asymptomatic or mildly symptomatic, we don't need 70% immunized to achieve a functional level of immunity, in my view.
 
Israel is so far ahead of everybody else, they'll give us a good peek at herd immunity thresholds.

As long as there are no minks in Israel. :) (Animal transmission can expand the "herd" a bit.)

Edit: wow, I just looked and Israel has vaxxed 93.5 out of 100 people! (US is at about 23%.)
 
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Montecfo said:
It seems to me we are beginning to achieve what I will call "functional" herd immunity. By vaccinating the people at highest risk first, and with a meaningful number having immunity due to exposures to Covid or other coronaviruses, hospitalizations are on what is probably a steady path lower.

And as vaccinations accelerate, with the JNJ vaccine coming on and kinks begining to work themselves out, more and more people will be immune.

Experts have talked about this new trajectory, not using these words but I think this is what is happening. Since most cases are asymptomatic or mildly symptomatic, we don't need 70% immunized to achieve a functional level of immunity, in my view.
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+1 Numbers have sure been encouraging in recent months.
 
twaddle said:
Israel is so far ahead of everybody else, they'll give us a good peek at herd immunity thresholds.

As long as there are no minks in Israel. :) (Animal transmission can expand the "herd" a bit.)

Edit: wow, I just looked and Israel has vaxxed 93.5 out of 100 people! (US is at about 23%.)
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Maybe they could send the US some foriegn aid.
 
twaddle said:
Israel is so far ahead of everybody else, they'll give us a good peek at herd immunity thresholds.

As long as there are no minks in Israel. :) (Animal transmission can expand the "herd" a bit.)

Edit: wow, I just looked and Israel has vaxxed 93.5 out of 100 people! (US is at about 23%.)
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That is not correct. Israel has vaccinated a bit over 50% of its population, but more than 90% of its population that is over 50 years old.

https://www.washingtonpost.com/worl...a3c3f2-7526-11eb-9489-8f7dacd51e75_story.html

"Almost 90 percent of Israelis over 50 have been fully vaccinated.

Israel’s small population of about 9 million, and its universal national health system, makes it a natural vaccine lab for the world. The program has inoculated more than 4.6 million people with at least the first injection, the fastest per capita pace of any country. More than 3.3 million have gotten both shots."
- - - - - - - - - - - - - - -
Unfortunately, the number of infections in the USA has started to rise again in the last few days.
 
Popeye said:
Israel is at about 90 doses per 100 people. That breaks down to over 37 per 100 with two doses and another 52 with the first dose. The Bloomberg tracker breaks it down nicely.

https://www.bloomberg.com/graphics/covid-vaccine-tracker-global-distribution/
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Yes, I have seen people misled by that statistic. A perfect record - every last person vaccinated with a two dose vaccine - would see that number at 200. It is going to be a more complicated and less useful number now that the single dose Johnson & Johnson vaccine is also being used.
 
Gumby said:
....It is going to be a more complicated and less useful number now that the single dose Johnson & Johnson vaccine is also being used.
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But it doesn't need to be more complicated. All that the statisticians need to do is state the number of folks who are "vaccinated". Vaccinated meaning having received 100% of the dosage specified by the vaccine manufacturer.
 
The important point (IMO) is that Israel is closest to herd immunity, well ahead of the US. Israel is still reporting several thousand new cases per day.
 
twaddle said:
Israel is so far ahead of everybody else, they'll give us a good peek at herd immunity thresholds.

As long as there are no minks in Israel. :) (Animal transmission can expand the "herd" a bit.)

Edit: wow, I just looked and Israel has vaxxed 93.5 out of 100 people! (US is at about 23%.)
Click to expand...

If Europe is the poster child for how to be penny-wise and pound-foolish so as to mess up getting and providing the vaccine, Israel is the poster child for how to do it right.
 
Ronstar said:
But it doesn't need to be more complicated. All that the statisticians need to do is state the number of folks who are "vaccinated". Vaccinated meaning having received 100% of the dosage specified by the vaccine manufacturer.
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That would seem to make the most sense.
 
Montecfo said:
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
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I've been wondering about the 20,000 folks who received the Pfizer shots last summer/fall during the Phase III trial. Has Pfizer been following them to see how many have developed mild/moderate/severe/fatal COVID at various times (say, 4 weeks, 8 weeks, 12 weeks) following the 2nd dose? It would be great to see that data, if it exists and has been published. To date, I've seen nothing from Pfizer itself other than their initial data made public late last year.
 
It may spread so easily, but the battle against this virus is working.

After the last couple of months of improvement in our numbers here in Louisiana, today we had a terrific announcement! The following quotes are from this article:

https://www.theadvocate.com/baton_r...cle_4e997da0-7b78-11eb-b7fc-bbc7293d156e.html

After seeing the worst spike of the pandemic recede in recent weeks, Gov. John Bel Edwards on Tuesday moved the state into the loosest phase of coronavirus rules to date, allowing bars statewide to reopen indoors and resuming live indoor music.

The decision to relax the restrictions on business occupancy, gatherings and other settings comes as most – but not all – regions of the state continue to see improving COVID-19 trends. Meanwhile, Edwards’ administration and federal health officials continue to sound the alarm about more contagious variants of the virus circulating before most of the population can get vaccinated.
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This despite the fact that
only about 14% of Louisianans have received one shot of the vaccine so far. About 8% have received both shots, which give people full protection.
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So, once the vaccinations have had the chance to have more of an effect, it is possible that our numbers here might be even better.

New Orleans is keeping stricter rules than the rest of the state, with no indoor live music still in the birthplace of jazz (and some say blues as well). Frank and I are about a mile outside the city limits in an urban suburb so I expect New Orleanians will be headed out here in droves to listen to live music inside, here in our suburb. Just in time because we have been having another cold (cool?) snap and it's miserable to sit outside in the rain with evening temperatures down in the 40's (brrr).

Hopefully now the fairly crippled local music scene can begin to revive and musicians can get back to doing what they do best, entertaining us with their sweet music.
 
Congrats W2R to Louisiana! I’m very happy for Texas today as well.
 
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