The Herd Immunity Theory is in Serious Doubt

Mish

Study suggests widespread long-term herd immunity will be difficult to achieve.

Covid-19 Antibodies Waning Over Time

The herd immunity thesis claims that if enough people get Covid they will become immune to reinfection slowing the spread of the disease.

However, an Antibody Study Shows Immunity May Wear Off.

The survey of 365,000 adults in England who tested themselves at home using a finger-prick test showed the proportion of people testing positive for Covid-19 antibodies declined by 26.5% between June 20—12 weeks after the peak of infections in the country—and Sept. 28.

Doctors don’t yet know whether antibodies confer any effective immunity against reinfection by Covid-19. But even if they do and the results of this survey are confirmed, it suggests the prospect of widespread long-term herd immunity to the virus will be difficult to achieve. Herd immunity occurs when enough people in a population develop an immune response, either through previous infection or vaccination, so that the virus can’t spread easily and even those who aren’t immune have protection.

The authors admitted the trial had limitations. “It included nonoverlapping random samples of the population, but it is possible that people who had been exposed to the virus were less likely to take part over time, which may have contributed to apparent population antibody waning,” they said.

Blow to Herd Immunity Theory

A 26.5% reduction in antibodies in just 12 weeks is quite a significant reduction. 

If accurate, it calls into question expected results from vaccines as well. 

Whereas I stated "if accurate" and "calls into question" the Financial Times says Covid-19 herd immunity theory dealt blow by UK research.

Jonathan Ball, professor of molecular virology at Nottingham university, said that while the React-2 study “confirms suspicions” about waning immunity in elderly populations, it is less clear what the relationship is between declining immunity and susceptibility to reinfection.

False Promise of Herd Immunity 

Nature.Com discusses the false promise of herd immunity for COVID-19.

Proposals to largely let the virus run its course — embraced by Donald Trump’s administration and others — could bring “untold death and suffering”.

In early October, a libertarian think tank and a small group of scientists released a document called the Great Barrington Declaration. In it, they call for a return to normal life for people at lower risk of severe COVID-19, to allow SARS-CoV-2 to spread to a sufficient level to give herd immunity. People at high risk, such as elderly people, it says, could be protected through measures that are largely unspecified. The writers of the declaration received an audience in the White House, and sparked a counter memorandum from another group of scientists in The Lancet, which called the herd-immunity approach a “dangerous fallacy unsupported by scientific evidence”.

“Surrendering to the virus” is not a defensible plan, says Kristian Andersen, an immunologist at the Scripps Research Institute in La Jolla, California. 

“Attempting to reach herd immunity via targeted infections is simply ludicrous,” Andersen says. “In the US, probably one to two million people would die.”

Guessing Game

Clearly everyone is guessing. 

It's equally clear that herd immunity proponents are making potentially disastrous guesses.

The same applies to the notion that vaccines will be immediately successful.

But the worst guess goes to Donald Trump who stated on February 26, "The 15 (cases in the US) within a couple of days is going to be down to close to zero.

Mish

Comments (91)
No. 1-27
ajc1970
ajc1970

Measuring the antibodies is a proxy for measuring acquired resistance to a disease. You can keep resistance after you no longer test positive for specific antibodies.

You hinted at it, but many people seem to miss this point: every vaccine humans have ever made just piggy-backs off the immune system's native mechanisms. If we can't naturally develop immunity, our vaccines won't work either.

PecuniaNonOlet
PecuniaNonOlet

Herd immunity hasnt worked for an endless list of viruses: hiv, herpes, cold, flu, corona, chicken pox, measles, small pox, etc. Why would this be different? We have already seen people get re-infected and some have died.

I said it before and will say it again, 2021 is economically toast. I am thinking 2022 wont be much better.

Goblueguy
Goblueguy

So, if I understand, herd immunity and vaccine effectiveness will be correlated. If herd immunity isn't possible, vaccine will be ineffective, and vice versa. So, if true, we lock down until when? This part of the equation is what I don't understand

Realist
Realist

Scientists are learning more about this virus every day, but they are a long way from knowing it well enough to make a recommendation to try to achieve herd immunity (or better known as herd mentality, according to Trump).

I find it shocking that some are willing to risk massive numbers of deaths and illnesses in order to attempt to achieve herd immunity, without knowing if it is even possible.

From what I have been reading in the last few months, it is becoming clearer to me that there is a very high likelihood that the virus will be endemic. It will be very difficult to completely eradicate it, much like measles, chicken pox, or even like colds and flus.

Vaccines are likely to provide some protection for short time periods, but we will probably have to take them on a regular basis for many years.

Fortunately, the virus appears to be mutating to be more contagious, yet less lethal, over time, which is not uncommon.

However, there is unlikely to be a magic bullet vaccine or therapy that will completely ease our concerns. It seems that we will be dealing with it for quite a long time, so we need to properly manage it, in order to better mitigate the consequences.

selimtk
selimtk

This does not show anything. It is not even a study, but a survey. We need better data both for natural and vaccines

selimtk
selimtk

Mish, I think you need to change the title...

Eddie_T
Eddie_T

Herd immunity here would take years to happen, to get to the numbers it would take....and the healthcare system would be overwhelmed in the meantime. That was my conclusion, arrived at back in the spring.

I suspect the virus will become endemic....just like other coronaviruses....we will be very lucky if any of the five or so vaccine approaches being tried.....or if any of the vaccines for other diseases that might convey some cross-immunity...(and it is possible that one might).....actually provide anything close to long term immunity.

But we can still control it with good protocols..no matter what....if we can get really good compliance with the public health measures that we know do work. If nothing else works, we might try common sense. Eventually.

Nasty Edwin
Nasty Edwin

Protect the obese, the elderly and those with underlying conditions. The rest of us have very little risk.

Carl_R
Carl_R

At this point, in addition to taking precautions to avoid it, the best plan would appear to be to keep your personal immunity up by maintaining a healthy body weight, exercising, taking Vitamin D, Zinc, and Melatonin, plus a zinc ionophore such as quercetin or green tea, and then wearing a mask so that if you get it, you get a mild case. Do that, and then go about your normal business.

Obviously you can't completely protect the elderly and the at risk, but you can do the best to minimize the numbers who die. You can also try to improve treatments. The longer the whole thing is stretched out, the better the treatments will get.

Sechel
Sechel

The question is how you get to herd immunity. Mass infections means too many people die or succumb to serious health problems. But via vaccination there are far fewer health risks. We're probably all going to have to get a yearly vaccine.

Webej
Webej

What a lot of muddled thinking.
Herd immunity is simply nature.
Herd immunity is not a theory or a proposal but an important epidemiological concept: Immunity among the general population protects those who do not have it. That is why Europeans died of small pox at less than 1/10th the rate than native Indians, of whom 90% were wiped out.
In vaccination theory (vaccination is a shortcut to acquired immunity after surviving infection; vaccination is predicated on acquired immunity), the herd immunity threshold is a theoretical number that indicates how many people you need to vaccinate to make sure that those who can't be vaccinated (infants, infirm, immune compromised, allergenic) will be protected. That threshold is not the actual empirical number required. It is the number required without knowing in advance what coefficients apply for communcability and infectiousness and assuming everybody is equally prone to infection. Those coefficents serve to dampen the spread considerably, but are pretty much impossible to determine beforehand.

Waning of antibodies is normal (it would be inefficient to produce them when not needed). It was observed long before Covid, particularly with respect to Corona viruses. It doesn't mean your body no longer knows how to make them. Waning antibodies does not imply your are equally susceptible. Antibodies are like artillery, but there is also sentry duty (skin and mucosal immunity), scouting, intelligence gathering, and carpet bombing. Back in May a Swiss group discovered that more than 50% of blood samples antedating the pandemic showed T-cell (cross-) reactivity to the virus. Many similar studies have come to light.

To say that the people advocating a more traditional approach are risking millions fails to discount the cost of the current approach; the UN estimates 130 million dying from lack of food availability (money) due to the lockdowns across the globe, and that is just a beginning of the long term costs. It also ignores that a number of these scientists at odds with "scientific evidence" belong to the top figures in the field. We already know the IFR is about 0,16%, trending to 0,10%, heavily concentrated on geriatric patients, in the same order of magnitude as a bad influenza epidemic.

Or we can think there has been a fundamental break with nature, such that, as Krutika Kuppalli (congressional expert witness) puts it: We will never return to pre-Covid days even after a vaccine. We will need to continue to mask in perpetuity.

Obviously a failure of evolution to have one encoded in our DNA.

All policy requires navigating potential risks to the right and to the left.
The vaccines being tested are not being tested for their impact on morbidity, and may make no difference to mortality among the infirm.

Felix_Mish
Felix_Mish

Others who have looked in to the antibody testing situation may know better (please chime in), but it's my understanding the accuracy of antibody tests is ... a lot worse than you think. As in, don't take sure-win bets from guys in white coats or pocket protectors.

Too, last I looked at the FDA site, the accuracy of the tests used to detect whether you have the disease right now is dependent on the stage of the disease you're at. Covid19 tests are accurate like you think tests should be if the stage is juuuuust right and test procedures are executed perfectly, too.

Great post @Mish and great comments, @Webej

Jojo
Jojo

“Attempting to reach herd immunity via targeted infections is simply ludicrous,” Andersen says. “In the US, probably one to two million people would die.”

And that is NOT a large number against a population of 330+ million! And please don't give me the crap about "but if it was YOUR relative...". It wouldn't make any difference at all to me. Stay healthy, hope for the best.

Jojo
Jojo

First, a Vaccine Approval. Then ‘Chaos and Confusion.’
Come spring, Americans may have their choice of several so-so coronavirus vaccines — with no way of knowing which one is best.
Carl Zimmer | Oct. 12, 2020

The United States may be within months of a profound turning point in the country’s fight against the coronavirus: the first working vaccine.

Demonstrating that a new vaccine was safe and effective in less than a year would shatter the record for speed, the result of seven-day work weeks for scientists and billions of dollars of investment by the government. Provided enough people can get one, the vaccine may slow a pandemic that has already killed a million people worldwide.

It’s tempting to look at the first vaccine as President Trump does: an on-off switch that will bring back life as we know it. “As soon as it’s given the go-ahead, we will get it out, defeat the virus,” he said at a September news conference. But vaccine experts say we should prepare instead for a perplexing, frustrating year.
....

ErnieWeaver
ErnieWeaver

"In the US, probably one to two million people would die."

This is crazy.

The IFR is supposedly ~0.2% according to the best estimates. US pop, assuming all are vulnerable, is ~330m => We have an absolute ceiling of ~660,000.

10% of the population are so young they are basically unaffected -> 600k.

Subtracting the already infected leads to 30% reduction: estimate for the UK deaths ~= 45k, divide by IFR => 22m, UK pop = 65m, ~30%.

Herd immunity is supposedly a thing at about 70%, so the meaningfully susceptible population who may die is 40% of 600k, or 240k.

This is still possibly artificially high, but all in all throwing around "millions" is just irresponsible.

Tedwardspharmd
Tedwardspharmd

Immunity as measured by antibodies (IgG) naturally declines over time. The half life of an antibody is around 21 days. However, antibody production (via B-Cells) is what drives an individual’s immunity. The immune system is much more complex than simply measuring an antibody level to a specific protein. This is not to say that one won’t become reinfected—we are constantly facing reinfection from a variety of pathogens on a daily basis. However, subsequent infections are usually mild or even asymptomatic (but not always).

njbr
njbr

Right now, we don't know what the future holds.

And rather than better, the second time around, people have had worse cases.

A virus that affects lungs, hearts, brains--how many times do you want to get it?

And logically, if these vital organs are affected adversely on the first go-round, do you really think that they will be helped or not further affected by another infection?

njbr
njbr

The key question:

CAN ANYONE POINT OUT A VIRAL ILLNESS WHERE HERD IMMUNITY HAS BEEN ACHIEVED ??

numike
numike

News about Covid-19 should be illegal, tweets Trump

TimeToTest
TimeToTest

Just to clear this up - Herd immunity is the only way a virus can be defeated. Herd immunity with a vaccine or without a vaccine. It’s such a taboo subject to talk about but it’s is the only way any virus has been stopped or slowed.

Reinfection at this point seems very unlikely in the short/medium term.

AussiePete
AussiePete

A study of 191,000 peoples' vitamin D levels showed that higher levels of 25(OH)D (vitamin D) gives a 54% reduction in risk of developing Covid 19

Jackula
Jackula

Perhaps some herd resistance would be a better term than herd immunity with respect to Covid. Herd immunity is a good term when applied to chicken pox, not corona-viruses. Suspect similar to cold corona-viruses one gets some resistance for some years so one gets a milder case upon re-infection some time after the first case. It'll be awhile before we truly know but from the research I've read something close to this will be our findings in time.

RonJ
RonJ

"Covid-19 Antibodies Waning Over Time"

T cell immunity.

Only 17% of the people on the Diamond Princess got sick. People have exposure to previous corona viruses. This may provide T cell immunity to Covid-19 to upward of 50% of people exposed.

It is not just about antibodies.

ionicmantoms
ionicmantoms

Very well written, @Mish.

Deedee43
Deedee43

I think people may forget that the purpose of the lockdown was to keep from overwhelming the healthcare system. I haven't forgotten the field hospitals we had here, we still have some set up in case they are needed. It also bought time to do all of that vitamin d research etc...if the healthcare system gets well beyond capacity, mortality goes up from all causes. Regarding immunity, the field of immunology is so incredibly complex and this virus attacks and provokes the immune system all at once-I think it will be a while before we know the answer to the question of the possibility or herd immunity or sustained immunity.

Captain Ahab
Captain Ahab

Skipping to the real issue--which is not herd immunity or vaccines, or masks, or social distancing...

Decision making under complex, fast-changing conditions subject to incomplete information (aka uncertainty) is something very few people have the capacity to do, especially in government and most institutions. Procedure manuals (e.g.) and past practice/experience generally limit our perspectives on situations. What tries to streamline a process will work with known situations (ie. risk); however, it hinders uncertain situations, and may make them worse.

Along comes Covid-19; you're in charge; what do you do?
Depend on your experts! They don't know! They get out the manual... They cover up their incompetence (masks not needed!). Panic sets in with toilet paper--you lie to calm thing down. Prior testing procedures don't work.... Monumental mess results. Quarantine everyone. Economy screwed. Bigger monumental mess. No one has the remotest idea what to do to actually 'solve' the problem until information becomes more certain. State governors are incompetent at dealing with uncertainty. So is the military in most cases.

I could go on, but the point should be clear. What is missing is people who 'think' under uncertainty, have minds that are holistic (focused on the big picture), and are very creative.

BTW, my Covid scorecard: Trump gets an F, Biden's Plan gets an F (it's the 'plan' that fails every time there is uncertainty.)

What to do? A radical restructuring of how we address uncertain situations. A national evaluation to identify creative people who can deal with uncertainty. Let them set up their mode of operation.... you get the idea.


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