Why herd immunity to COVID is no longer possible

I said I'd do this in another thread, but I'll try to make this as short as possible.

The herd immunity threshold is 1 - 1/r where r is the spread rate. As a simple example, if r is 2 (meaning each infected person infects 2 others on average), then the HIT is 1 - 1/2 = 50%. If 50% of the people are immune, then one of the 2 people to whom an average person would spready it to are immune, he can only spread it to one other person. If r is 3, then the HIT is 1 - 1/3, or 66.6%, meaning 2 of the 3 people to whom the infectee would normally spread it to are immune, so he can only spread it to one person. Once you drive the r below one, the virus has no place to go and will die out.

(If you're following so far, you may observe that the HIT is actually slightly above the above formula because you need the r to be below 1, but that's close enough as a simple formula.)

Okay, back in the early days of COVID, we were looking at an r of about 3.5 and thus people assumed HIT of about 70%. This assumed that all previously infected people were 100% immune.

It's now clear that previous infection, while generally providing robust protection against serious problems and death, does not always prevent re-infection to the point of possibly being spreaders. Similarly, the best vaccines, while protecting against death and hospitalization well in excess of 90%, seem to provide weaker protection against the possibility of asymptomatic or minor illness with ability to spread, especially against variants such as Alpha and Delta.

The variants, especially Delta, have also proven more contagious than the Wuhan-1 COVID version. Some people put the r as high as 6. But let's say it's 5. An r of 5 means a HIT of 80% immunity. The best vaccines and natural infection are probably not capable of providing 80% protection against asymptomatic spreader capabilities against the Delta variant. This means that even if 100% of people were vaccinated or previously infected, we probably are short of the herd immunity threshold.

COVID is here to stay. We need to learn to live with it. If we vaccinate, death or hospitalization becomes possible but very unlikely. COVID becomes a cold/flu if everyone is vaccinated. COVID is headed for cold/flu status anyway in the long term once we reach 100% seroconversion.

This is why, except for local emergencies (i.e., where the healthcare system is being stressed in a given area), non-pharmaceutic interventions merely kick the can down the road.

Very good sh76. I'm glad sanity is coming back to this forum.

@sh76 said
I said I'd do this in another thread, but I'll try to make this as short as possible.

The herd immunity threshold is 1 - 1/r where r is the spread rate. As a simple example, if r is 2 (meaning each infected person infects 2 others on average), then the HIT is 1 - 1/2 = 50%. If 50% of the people are immune, then one of the 2 people to whom an average person would spready it to ...[text shortened]... s being stressed in a given area), non-pharmaceutic interventions merely kick the can down the road.

@sh76

If you get COVID without being vaccinated being hospitalized or getting killed is highly unlikely.

No reason to believe that after you have gotten sick and recovered you will not become immune to covid and it's variants. Studies say that natural immunity is at least 90 percent effective at producing immunity.

@eladar said
@sh76

If you get COVID without being vaccinated being hospitalized or getting killed is highly unlikely.

No reason to believe that after you have gotten sick and recovered you will not become immune to covid and it's variants. Studies say that natural immunity is at least 90 percent effective at producing immunity.

@mchill said
If you get COVID without being vaccinated being hospitalized or getting killed is highly unlikely.


I'm sure that's a great comfort to the 600,000+ Americans who perished from this virus, and to the thousands more, now fighting for their lives in hospitals. 🙄

@eladar said
The US population is about 330 million.

That 600k number represents 6 out of 3300 or 1 in 500. This was over 2 flu seasons so more like 1 in 1000 and most of those are 70 or older who already have a high death rate.

@no1marauder

How many of those deaths were the result of people avoiding hospitals. People who would have gotten medical help would have been more likely to survive a few more years.

By the way I simply said that most of the people who have died are 70 or older. The elderly are known to be a group much more likely to die from viruses.

To claim that all of society is at great risk from COVID simply because the elderly are at risk is simply a lie. Face it, your position on the covid matter is a complete hoax.

@eladar said
@no1marauder

How many of those deaths were the result of people avoiding hospitals. People who would have gotten medical help would have been more likely to survive a few more years.

By the way I simply said that most of the people who have died are 70 or older. The elderly are known to be a group much more likely to die from viruses.

To claim that all of society is a ...[text shortened]... elderly are at risk is simply a lie. Face it, your position on the covid matter is a complete hoax.

@mchill said
Your concern for human life is touching. I'm very thankful you're not running things -

@eladar said
@no1marauder

How many of those deaths were the result of people avoiding hospitals. People who would have gotten medical help would have been more likely to survive a few more years.

By the way I simply said that most of the people who have died are 70 or older. The elderly are known to be a group much more likely to die from viruses.

To claim that all of society is a ...[text shortened]... elderly are at risk is simply a lie. Face it, your position on the covid matter is a complete hoax.

@no1marauder said
This has also been pointed out to you numerous times, but far more than the elderly are "at risk". 125,000 COVID19 deaths in the US were non-elderly.https://www.statista.com/statistics/1191568/reported-deaths-from-covid-by-age-us/

@eladar said
Those numbers are not enough to shut down jobs and put so many people on unemployment.

You are taking 60k people per flu season.

@no1marauder said
This crap again.

COVID isn't flu.

There were virtually no deaths in the US until after the peak of flu season had been reached (which is normally February) in 2021. Your attempt to make COVID a "flu" and then misleadingly add in an extra flu season has been debunked many times on this Forum.

The pandemic would have caused large amounts of unemployment regardless ...[text shortened]... edictions regarding this pandemic. Quite frankly, you don't know now and you never did, have a clue.

@eladar said
Looks like you missed out on 60k deaths per flu season.

60k deaths per flu season is nothing to go wild about.