SARS-CoV-2 Coronavirus (COVID-19)

..... back when you are just seven or eight years old?

.

 

i wish

 

Here is another link, pointing to an actual herd immunity study on one of the 'common cold' coronaviruses:

CNN opinion: Herd immunity is a fantasy

"... Human coronaviruses in general have not been known to engender herd immunity. They've infected us like clockwork for decades — many of us many times over the course of our lives. Until recently, it was unclear whether this would be the case for SARS-CoV-2. Scientific case studies of two patients reinfected with Covid-19 — one in Hong Kong and the other in the United States (which is still undergoing peer review) — have since answered that question. The only one that remains is how often reinfection occurs.

What might shed some light on this issue is a collaborative, multiyear study led by researchers from the Netherlands and Kenya on the human coronavirus NL63 (HCoV-NL63), a member of the coronavirus family that isn't lethal but is endemic to populations worldwide. Like other nonlethal human coronaviruses, which likely infect us all at least once in our lifetime, HCoV-NL63 causes what we'd call a common cold. Three key findings from this study, which was published in 2018, can help inform our understanding of the Covid-19 virus SARS-CoV-2 and its ability to reinfect us.

The study was carried out across homes and hospitals in Kilifi County, Kenya, where researchers tracked the circulation of multiple coronaviruses throughout the community over a span of six years. The first relevant finding was that some patients weren't reinfected just once, but twice. One person even contracted the virus four times. This tells us that immunity to HCoV-NL63 was short-lived — so much so that some were reinfected within as little as three months.

The second significant finding was that a surprising number of patients had higher viral loads upon reinfection than they did during primary infection. ...

The third significant finding is that in six years, herd immunity to HCoV-NL63 was never acquired, and the virus continued to persist for the entire duration of the study. ..."

 

It seems that one city may have reached the lower threshold of "herd immunity". But it wasn't pretty, and it may not be lasting.

ScienceNews.org: A Brazilian city devastated by COVID-19 may have reached herd immunity

Blood donations suggest that up to half of Manaus was infected at the epidemic’s peak

The good news: tests of blood donations found antibodies peaking at 52% of donors in June, the peak of the local epidemic. Cases and deaths declined steadily after that, despite relaxing of social distancing measures, suggesting that herd immunity was occuring.

The bad news: at peak, the city's overall death rate was 4.5X the normal for that season. "Hospitals and cemeteries struggled to keep up, and mass graves were dug to bury the dead."

And "after that peak, seroprevalence fell, reaching 30 percent in August, a consequence of both waning antibody levels in people already infected and lower transmission rates, the researchers say."

Some things to beware of: the study is not yet peer reviewed, the antibody testing was not on a random sampling of residents, and the city has a particularly low fraction of elderly, only 6% over age 60.

 

COVID-19 Pandemic Planning Scenarios | CDC

 

They do quite a job describing the scenarios in great detail, but somehow I totally missed the range of predicted outcomes in each case.

 

there's been an upward trend in many places over the last few weeks including here.

ma icu's hit the july fourth number today. governments are still reopening venues, and it looks like predictions for the second surge may be correct.

meanwhile, no one in authority has a plan, but i'll leave that for the other thread

 

yep. schools, sports, indoor activities, it's the perfect storm

 

'disney lays off 28,000 employees'. business is bad in the theme parks, restricted travel, reluctant fans.

some people have common sense

 

our future may be a virtual reality...

 

I'm surprised they haven't gotten rid of more people already. Hopefully, at age 65, we'd do ok anyway - if the mouse handed us walking papers. But you got to feel sorry for the people living paycheck to paycheck. For the past year our group has been working off site, a few miles down the road. The 200 or so in our new/remote area? After asking around, nobody even knows anybody that got it - which makes sense, since such a huge contingent have no symptoms at all.
.

 

Not sure if this is what you're looking for, but the table/chart 'half way down the page' :

"...They are not predictions or estimates of the expected impact of COVID-19..."

Table 1. Parameter Values that vary among the five COVID-19 Pandemic Planning Scenarios.

Infection Fatality Ratio†

Scenario 1 , Scenario 2

0-19 years: 0.00002
20-49 years: 0.00007
50-69 years: 0.0025
70+ years: 0.028

Scenario 3 , Scenario 4

0-19 years: 0.0001
20-49 years: 0.0003
50-69 years: 0.010
70+ years: 0.093

Scenario 5: Current Best Estimate

0-19 years: 0.00003
20-49 years: 0.0002
50-69 years: 0.005
70+ years: 0.054

Could you please explain the math on how that below 3% (now) relates to any of the latest Infection Fatality Ratio(s) ?

 

i'm surprised cali isn't allowing a limited opening

 

my neice and her husband just bailed out of LA to albuquerque for a month. between covid and smoke, it hasn't been a pleasant place to be.