The World Health Organization has warned for months that herd immunity strategies would not work to control the new coronavirus Photo: AFP/File
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Experts slam 'dangerous fallacy' of virus herd immunity

38 Comments
By Patrick GALEY

Proponents of allowing the new coronavirus to circulate among populations in the hope of achieving herd immunity are promoting a "dangerous fallacy" devoid of scientific proof, dozens of health experts say.

In an open letter published in The Lancet medical journal, more than 80 specialists from universities across the world said that the only effective way of limiting excess deaths during the pandemic was to control the disease's spread.

The letter comes after numerous U.S. media last week reported that senior Trump administration officials had voiced support for an online declaration advocating herd immunity which gathered more than 9,000 signatories worldwide.

As a second COVID-19 wave batters Europe, several countries have reintroduced controls on movement and implemented regionalized lockdowns.

The authors of the letter said that the social and economic impacts of confinement had led to "widespread demoralization and diminishing trust" in government measures to get a handle on the virus.

The second wave has also led to a renewed interest in so-called herd immunity, which suggests allowing a large uncontrolled outbreak among people considered to be at low risk of death or serious illness from the virus.

The health experts listed numerous flaws in the concept.

Firstly, "uncontrolled transmission in younger people risks significant morbidity and mortality across the whole population," the letter said.

This would have a catastrophic human and financial cost, besides overwhelming healthcare systems.

The authors also noted that it is possible to become reinfected with COVID-19.

Herd immunity offers no guarantee that those who caught the virus would remain immune to it for any meaningful length of time. This would present a risk to vulnerable populations for "the indefinite future", the authors said.

Such a strategy would result in "recurrent epidemics" of COVID-19 similar to those caused by numerous infectious diseases before vaccines were invented.

"It would also place an unacceptable burden on the economy and healthcare workers, many of whom have died from COVID-19 or experienced trauma as a result of having to practise disaster medicine," they wrote.

The World Health Organization has been warning for months that herd immunity for COVID-19 was impossible without untold casualties.

WHO chief Tedros Adhanom Ghebreyesus said the concept was "unethical".

"The vast majority of people in most countries remain susceptible to this virus," he said. "Letting the virus circulate unchecked therefore means allowing unnecessary infections, suffering and death."

WHO emergencies director Michael Ryan warned back in May that any country pursuing herd immunity were making "a really dangerous calculation".

© 2020 AFP

©2020 GPlusMedia Inc.

38 Comments
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To be clear, "herd immunity" by itself is not a fallacy. Saying that rampant spreading as a safe way to achieve it is the one that lacks logic.

Every country is pursuing herd immunity. The moment the infection became a pandemic the other path (eradication by completely stopping new infections) became realistically impossible. The important part is understanding that this is to be done either by controlling the spreading to a slow crawl that can be managed without unnecessary loss of lives (but that requires also putting a big brake to the economy) or by developing effective and safe vaccines or treatments that eliminate the risk of complication.

12 ( +15 / -3 )

I highly recommend American conservatives to strive for herd immunity as their political, cough cough, "leadership" advocates. The sooner the better too.

4 ( +9 / -5 )

The promotion of dangerous fallacies goes from a few people to a group of writers spreading garbage on social media, then picked up by pundits on a certain channel, then touted by pseudo scientists hired for the purpose, then back to writers for another round.

People, like Pavlov’s dogs, start to salivate when they hear one of these cycles begin. Opposition newscasters then start preparing questions of the form, “How (adjective) were YOU when you heard that (news item sentence)? This is then run by 4-5 experts who express varying degrees of disgust or dismay at the news.

How astonished were you when you heard that Covid cases in Sweden were rising again? How amazed are you to hear that we have so much discussion and so few actions that make sense? Will people ever act normal again?

3 ( +6 / -3 )

I happen to think that we should, while protecting the most vulnerable, let the virus spread freely as long as the hospitals are not overwhelmed. I particularly think this should have been done this summer, when people are less susceptible (warmth, humidity, vitamin D...). And there are a number of experts who say similar things, talking about a safe spread. I think lockdowns have caused more damage than good, and are probably at least partly associated with the coming reset.

If a truly safe and effective vaccine becomes available, great. But we should not put all our hopes into it.

Also, I really hate this constant stream of articles slamming those who offer alternative views. I get very suspicious when they try too hard to control the narrative

-12 ( +3 / -15 )

I happen to think that we should, while protecting the most vulnerable, let the virus spread freely as long as the hospitals are not overwhelmed.

That is the thing, the expert's opinion is that the only way to reliably avoid overwhelming hospitals and protect the most vulnerable people is NOT to let the virus spread freely. They have the experience and data to prove it.

And there are a number of experts who say similar things, talking about a safe spread. 

Who are those experts? what are they experts in? and most importantly, on what evidence do they base their opinion and how do they discuss that the scientific consensus is on the opposite direction?

I mean, "a number of experts" will say absolutely everything, that the moon is made of cheese or that vitamins are the ones that make people catch COVID-19, after all "0" is a number, or they could be experts in folding toilet paper.

How about one full association of professionals that have anything to do with infectious diseases, epidemy control or public health management? After all, its not like not even one of those organizations supports "free spreading" is it?

I think lockdowns have caused more damage than good, and are probably at least partly associated with the coming reset.

False dichotomy, lockdowns are not the only way to prevent the spreading of the pandemic, there are many kinds of measures and many kinds of degrees for each.

Also, I really hate this constant stream of articles slamming those who offer alternative views. I get very suspicious when they try too hard to control the narrative

Alternative views are not the problem, unsubstantiated or demonstrably false views are, there is no other thing to do with people that propose anti-scientific measures just because they like them (or because some supposed experts without any data, nor names, say it). Valid, scientific, objective opinions well founded with reliable data and that do not depend on hidden conspiracies impossible to prove, are recognized easily as part of the conversation, it is just not coincidence that "free spreading" is not part of them.

6 ( +10 / -4 )

How about one full association of professionals that have anything to do with infectious diseases, epidemy control or public health management?

Oh, you mean the ones that must toe the line in order to continue receiving funding from Fauci and Gates?

There are plenty of "valid, scientific, objective opinions well founded with reliable data" out there that are not expressed by professional associations.

-8 ( +2 / -10 )

Oh, you mean the ones that must toe the line in order to continue receiving funding from Fauci and Gates?

All of them? in the world? not realistic, just magical thinking.

When your only argument is a hidden conspiracy to control every single association of professionals in the world you may as well just say you don't have any argument. It may surprise you, but nobody has that kind of money.

There are plenty of "valid, scientific, objective opinions well founded with reliable data" out there that are not expressed by professional associations

And yet you keep offering none, just "a number of them" as if that was some kind of reference, not a single scientific paper with well described methods and a complete discussion of the contradicting evidence, just "some people" that are incapable of convincing any of the literally thousands of associations of medical professionals in the world, because apparently two persons can fund them all and their research with trillions of dollars per year. And every single one of those associations decides what to do exclusively because of that money. Even if they and their family and friends lose much more by those measures that supposedly are totally unnecessary. Sorry, that does not make any sense. In the age of preprints there is no excuse to say scientific information is controlled.

9 ( +11 / -2 )

Look how well that worked out in 14th century Europe, and Africa, and...

6 ( +8 / -2 )

People who are succeptible to one conspiracy theory are likely to entertain more than one. These theories have no prophylactic effect, however, other than to insulate them from the truth. The people currently getting infected are also by and large Trump supporters and/or QAnon conspiracy theorists. Do the math.

4 ( +7 / -3 )

This deceptive article mentions the views of some health experts, mentioning that "it is possible to become reinfected with COVID-19" (yeah 5 or a dozen cases world wide so far).

Such a strategy would result in "recurrent epidemics" of COVID-19 similar to those caused by numerous infectious diseases before vaccines were invented.

Oh, I see, they are pushing the vaccines again! Why do we have so many articles pushing the "thank God for the vaccines" narratives, and no articles that honestly represent the views of the many experts that are promoting the herd immunity narrative, which is not a "dangerous fallacy devoid of scientific proof".

What we have here is an official narrative from people that have certain agendas. This narrative is supported by massive funding and the MSM, which promote that narrative and censor or attack anyone that does not toe the line.

-10 ( +0 / -10 )

Oh, I see, they are pushing the vaccines again! Why do we have so many articles pushing the "thank God for the vaccines" narratives, and no articles that honestly represent the views of the many experts that are promoting the herd immunity narrative, which is not a "dangerous fallacy devoid of scientific proof".

Links, please.

When you are using ‘many’, do these experts represent a majority view?

Your posts seem to indicate that you will seize upon anything which can help you along with the tiresome conspiracy theory about vaccines.

9 ( +10 / -1 )

Yeah, I have heard many virologists talking about this, as well as doctors treating covid19 patients, and other scientists analyzing the various Covid19 stats. On the MSM, we never get an honest representation of these views, instead we get the same constant nonsense repeated almost daily. I can't see how this could be anything but intentional disinformation, partly to sell vaccines, partly to inconvenience as many of us as possible perhaps to get most of us to accept their solutions, including the reset.

-11 ( +0 / -11 )

Yeah, I have heard many virologists talking about this, as well as doctors treating covid19 patients, and other scientists analyzing the various Covid19 stats. 

Don’t any of these experts write any papers or articles we can view? Surely there must be one or two.

My mind doesn’t automatically jump to the conspiracy theory. I’m not wired that way.

Links would be nice.

7 ( +8 / -1 )

This deceptive article mentions the views of some health experts, mentioning that "it is possible to become reinfected with COVID-19" (yeah 5 or a dozen cases world wide so far).

People that don't understand science or logic tend to think on fantastic absolute terms, and make mistakes because of that.

It is completely possible to become reinfected with COVID-19, the same as with every other infectious disease, there is nothing deceptive about that.

Oh, I see, they are pushing the vaccines again! Why do we have so many articles pushing the "thank God for the vaccines" narratives, and no articles that honestly represent the views of the many experts that are promoting the herd immunity narrative, which is not a "dangerous fallacy devoid of scientific proof".

One, because vaccines are a safe and effective health intervention that improved the life of all humans, so rational people expect this story of improvement to involve the pandemic also. It would be the normal situation.

Two, because nameless people without data are not worth of attention. You keep mentioning these imaginary experts but not even once you can reference their views expressed scientifically, as in a structured, systematic manuscript, the minimum required to take their view with even a hint of seriousness.

What we have here is an official narrative from people that have certain agendas. This narrative is supported by massive funding and the MSM, which promote that narrative and censor or attack anyone that does not toe the line.

No, that is just an imaginary conspiracy theory, that would require a thousand bill gates to dedicate their whole fortune.

Reality is that your beliefs are not supported by evidence, and many times are actually debunked by evidence, there is no need for any agenda to say that false things are false. It just requires being intellectually honest.

Yeah, I have heard many virologists talking about this, as well as doctors treating covid19 patients, and other scientists analyzing the various Covid19 stats. On the MSM, we never get an honest representation of these views,

I have heard many sociologists and psychologists that have proved that when people keep basing their arguments in the non-existent authority of nameless people that only them can see 100% of the time there are no such things, the sociologists have published over 100 papers about it, so it is true.

I can't see how this could be anything but intentional disinformation, partly to sell vaccines, partly to inconvenience as many of us as possible perhaps to get most of us to accept their solutions, including the reset.

Yes, people that are obsessed with a twisted view of the world are unable to accept reality, even if proved with mountains of evidence. They can't see, because it would decrease their value in their own eyes. It does not matter how irrational their beliefs are, many times they even resort to imaginary authority figures.

6 ( +7 / -1 )

Here is some simple arithmetic for Raw Beer and those of like mind. There are 330 million people in the United States. To approach herd immunity at least 70% of that 330 million people would have to have had been infected by Covid-19 and thus have anitbodies. That means 231 million Covid-19 cases. At least 1% of Covid-19 infections result in death. In some places the rate is higher than this but for the sake of keeping the arithmetic simple and non controversial we will stick with a conservative number. So 1% of those 231 million infections lead to death. That means at least 2,310,000, 2.31 million Americans, will die from Covid-19 before herd immunity is achieved. That is what your advocacy of herd immunity achieves. Lots of dead Americans, a number that rates as genocide. Worse still there is no guarantee any immunity achieved is lasting. All those deaths could be for naught. The virus is still too new to have any data to support the claim that there can be long lasting immunity achieved from an infection. But because too many on the right are ignorant of science as well as lazy and selfish there will be needless death and suffering in the US. The right would rather see over 2 million dead than wear a mask and put off going to a ball game or dining out in a restaurant. it's all about me and to hades with everyone else. I got my rights, never mind rights come with some obligations. The right will never talk about that.

5 ( +6 / -1 )

In an open letter published in The Lancet medical journal, more than 80 specialists from universities across the world said that the only effective way of limiting excess deaths during the pandemic was to control the disease's spread.

That is not an argument against herd immunity, which exists and will be achieved anyway. That is an argument for flattening the curve, i.e. avoiding to overload hospital capacity. I don´t think anybody has disagreed with that concept ever. The disagreement is about keeping these extreme lockdowns for extended periods, destroying peoples livelyhoods in the process.

The article headline is misleading.

-5 ( +1 / -6 )

Farmboy:

How astonished were you when you heard that Covid cases in Sweden were rising again? How amazed are you to hear that we have so much discussion and so few actions that make sense? Will people ever act normal again?

"Cases" have been somewhat rising in Sweden, whatever that means. However "cases" simply reflect testing, so it is a pretty irrelevant number. The death rate in Sweden has been completely flat since July, practically at zero. And the hospitals are not overloaded. So what is your point in bringing up Sweden?

-5 ( +1 / -6 )

Jimizo

Don’t any of these experts write any papers or articles we can view? Surely there must be one or two.

My mind doesn’t automatically jump to the conspiracy theory. I’m not wired that way.

Just off the cuff: John P.A. Ioannidis, Stanford University, or Sucharit Bhakdi, University of Mainz, Germany. Both epidemologists with credentials vastly superior to the censors at Youtube or Twitter who try to muffle them.

Both highly critical of the extreme authoritarian measures taken by many governments. Swedens Tegnell too is quite a bit more qualified to talk on the topic than the talking heads at the MSM programs. And I don´t know what "conspiracy theory" has to do with anything. When I see censorship, I am guilty of a "conspiracy" to call it out?

-5 ( +1 / -6 )

Cases" have been somewhat rising in Sweden, whatever that means. However "cases" simply reflect testing, so it is a pretty irrelevant number. The death rate in Sweden has been completely flat since July, practically at zero. And the hospitals are not overloaded. So what is your point in bringing up Sweden?

No. Cases indicate infections and infections in Sweden are rising sharply the last two weeks. Deaths lag infection by two weeks to a month. Your analysis is defective.

https://covid19.who.int/region/euro/country/se

4 ( +5 / -1 )

Desert Tortois

Here is some simple arithmetic for Raw Beer and those of like mind. There are 330 million people in the United States. To approach herd immunity at least 70% of that 330 million people would have to have had been infected by Covid-19 and thus have anitbodies. That means 231 million Covid-19 cases. At least 1% of Covid-19 infections result in death.

Ah, the good old "1%" fake math. Here is an article that addresses that. Please read it:

https://www.rt.com/op-ed/500000-covid19-math-mistake-panic/

-5 ( +1 / -6 )

The Federal government cannot mandate tight or loose controls on the people in order to control the epidemic. That is the responsibility of the States.

-2 ( +1 / -3 )

Desert Tortoise

No. Cases indicate infections and infections in Sweden are rising sharply the last two weeks. Deaths lag infection by two weeks to a month. Your analysis is defective.

https://covid19.who.int/region/euro/country/se

False. There is no link between "cases" and "deaths", as "cases" only reflect testing, and not the actual number of infection. And ironically, your suggested link between "cases" and "deaths" does not show up at all in the two charts on your link, conveniently posted one below the other. Look again. There NO spike in deaths following two weeks or a month after the spike in cases. Look at your link again.

-5 ( +1 / -6 )

Herd immunity requires that at least 60% of a population become infected. In the US that is a little more that 200 million people. And, by the way. 60% is a conservative number. The current death rate in the US is 2.87. So, let's assume it's 1.0 since actual infections are much higher. That says 2 MILLION PEOPLE will die. A virtual crime against humanity by the Trump presidency.

Herd immunity is usually discussed when a vaccine exits. So, for measles where immunity is lifelong, 80% or so of the population being vaccinated guarantees that those who cannot be vaccinated because of compromised immune systems can safely go to school, etc ... Other examples are polio, smallpox, and chicken pox.

Flu vaccines as well as one for SARS-CoV-2 when it arrives after completed phase-3 trials and verification only give seasonal protection, and as is well known, do not prevent reinfections.

With respect to Sweden the government itself admitted that too many people died. Denmark just next door successfully implemented the necessary restrictions to flatten the curves while minimizing deaths.

Remember: Economies always come back even when obliterated as in 1929 and 2008. The dead NEVER COME BACK.

Please a little compassion for others and the vulnerable. SARS-CoV-2 is devastating often will serious long timer after effects.

Wear a mask. The life you save may be your own.

5 ( +6 / -1 )

WilliamJames

Herd immunity requires that at least 60% of a population become infected. In the US that is a little more that 200 million people. And, by the way. 60% is a conservative number. The current death rate in the US is 2.87. So, let's assume it's 1.0 since actual infections are much higher. That says 2 MILLION PEOPLE will die.

How do you arrive at those wild numbers? I addressed the "1%" fallacy a few messages above.

Remember: Economies always come back even when obliterated as in 1929 and 2008. The dead NEVER COME BACK.

A destroyed economy kills more people than any Coronavirus can. How do you want to pay for hospital treatment when you have no income and hospitals are bankrupt? The "economy" is not something exists separately from real life.

Read about life in 1929 before wishing it on us.

-6 ( +1 / -7 )

Just off the cuff: John P.A. Ioannidis, Stanford University, or Sucharit Bhakdi, University of Mainz, Germany. Both epidemologists with credentials vastly superior to the censors at Youtube or Twitter who try to muffle them.

Could not find any scientific article where they properly discuss and defend with evidence the unrestricted spreading as a safe and effective way to achieve herd immunity. Only opinions where very specific, and strong measures of control are still recommended (just not full economic lockdowns) on one part, and opinions extrapolating from other infectious diseases and vaccines (still without proper statistical analysis to assess their value) for the other.

Again, full universal lockdown vs no measures whatsoever for the general population is a false dichotomy, and a proper discussion worth of evaluation requires a scientific report. Credentials are important only in the sense that they lets us expect a properly defended argument (with referenced data, a well described methodology and conclusions that include any contradicting argument). This is not something we can get from Youtube or Twitter.

3 ( +5 / -2 )

A destroyed economy kills more people than any Coronavirus can. 

NZ’s economy has not collapsed. Neither has Australia’s.

5 ( +6 / -1 )

@Zaphod

There are many different predictions of the actual death rate as different countries try different methods of controlling the virus. Your idea that the actual rate is at least ten times lower than the currently accepted rate of 1% however isn’t backed up by the actual data. A 0.1% death rate would mean that a bit over 200,000 Americans would die before herd immunity was achieved. First there is no guarantee that immunity is lasting, second more that 200,000 Americans have already died as a result of the virus, and third both infections and deaths are increasing. The death rate of the corona virus has already far exceeded the flu death rate which can be confirmed by looking at the “excess deaths”. Based on this actual data it does appear the death rate will approach the 1% mark.

Of course you’re welcome the interpret statistics anyway you want to fit your narrative but I hope most base there views on the actual data available.

5 ( +6 / -1 )

Here is some simple arithmetic for Raw Beer and those of like mind. There are 330 million people in the United States...

I'd say the problem lies in the numbers. The US average IQ of 98 versus 108 for Hong Kong, Singapore, 105 for China, Japan, Korea, and staying above 101 for Taiwan, Iceland, Switzerland, blah, blah, blah...

So at an average IQ of 98 and a population of 330,000,000, the US has almost 90,000,000 people below 90 IQ.

That's a lot of people who don't understand stuff very well. And how some people get elected . . .

Oh, and 65% of Americans say that they are above average IQ. And apparently 85% think that they are above average drivers.

This supports the findings that the US is ranked 38th in math.

5 ( +6 / -1 )

Here is some simple arithmetic for Raw Beer and those of like mind.

When doing arithmetic, you have to make sure you're starting off with the correct numbers. However, not everyone has the ability to do that; see Peter Neil's post.

The infection fatality rate for Covid-19 is around 0.23% overall, as inferred from seroprevalence data. For people below 70, the number drops to around 0.05%.

Worse still there is no guarantee any immunity achieved is lasting.

There is no guarantee that we will ever get a safe and effective vaccine. So you want to keep the vulnerable people locked up for ever?

Anyway, as I mentioned many times, those who recovered from the 1st SARS CoV (17 years ago) still have the memory lymphocytes that would protect them from a second attack. I suspect it will also be the case for SARSCoV2.

So, I'm not the one that is "ignorant of science" and it is our avoidance of herd immunity that will lead to needless death and suffering.

-4 ( +1 / -5 )

Anyway, as I mentioned many times, those who recovered from the 1st SARS CoV (17 years ago) still have the memory lymphocytes that would protect them from a second attack. I suspect it will also be the case for SARSCoV2.

Some of the people recovered still have reactive cellular immunity, not all of them. And the very important caveat is that those people were extremely symptomatic, we don't have information about cellular immunity from asymptomatic patients of COVID-19, only from a subgroup of patients that had heavy complications and vaccine volunteers. Your suspicions are biased towards what you want to believe, sustain them with real scientific data or else they are as real as the "numerous" virologists that have no name nor data or the imaginary career as a molecular biologist that some people pretend to have.

So, I'm not the one that is "ignorant of science" and it is our avoidance of herd immunity that will lead to needless death and suffering.

Which, as demonstrated by science requires either strict control of the spreading, a safe and effective vaccine or a completely effective treatment that eliminates the risk of complication even on patients with comorbidities, at this point there is no evidence that unrestricted spreading can avoid as much unnecessary deaths and complications as the real 3 options there are.

There is one thing worse than being ignorant of science, and that is being a denialist of science. A layman has no duty to know the science, but knowing it and use incomplete, misleading or false information to pretend it says the opposite of what actually is the consensus has no excuse.

4 ( +5 / -1 )

Virusrex

There is one thing worse than being ignorant of science, and that is being a denialist of science.

There is one thing that shows we are talking about religious-political bias and not science is, and that is when one side accuses the other of being "denialists".

This epidemic is not settled science with a broad consensus yet. There are experts on all sides of the issue how to approach it, some motivated by particular interests, and many "reputable" original predictions have been shown false. The best thing we can do is listen to several sides, and not just the one narrative promoted by the mainstream media and Big Tech.

-3 ( +1 / -4 )

virusrex

Could not find any scientific article where they properly discuss and defend with evidence the unrestricted spreading as a safe and effective way to achieve herd immunity.

...and neither do they. Why do we have to make up strawmen?

-3 ( +1 / -4 )

The virus herd immunity works well in China. They have the lowest infection rate. Oh wait, maybe it's because they have the antidote...

-3 ( +0 / -3 )

There is one thing that shows we are talking about religious-political bias and not science is, and that is when one side accuses the other of being "denialists".

That is unrelated, can it be proved that a person is actively trying to ignore the science and instead trying to mislead with invalid conclusions? then it can be accused without problem of being a denialist. The person is not ignorant of science, it is trying his best to misrepresent it. There is nothing political nor religious about it, it is simply true.

This epidemic is not settled science with a broad consensus yet. There are experts on all sides of the issue how to approach it, some motivated by particular interests, and many "reputable" original predictions have been shown false. The best thing we can do is listen to several sides, and not just the one narrative promoted by the mainstream media and Big Tech.

Nobody is talking about settling absolutely everything about the pandemic, but there are many things that are without problem understood well enough to say there is a consensus, nothing is ever absolutely decided in science, that is not what consensus means, what it means is that there is enough data for a vast majority of the professionals to share the same conclusions.

Of course some things will turn out false, that is what happens with something that is not completely known, but that does not mean that there was no consensus it only means that more information was necessary, not that people with invalid conclusions based on no data (or faulty data) magically have more of a chance of being right.

..and neither do they. Why do we have to make up strawmen?

You don't understand what the fallacy of strawman means, you are using it incorrectly. What is the argument that I supposedly said you sustain? there is no such thing.

You are replying to a request for scientific papers, articles for dissenters to the consensus to explain scientifically why their opinion is valid (as in supported by data). You reply with names, I could not find what was asked with such bad reference, so your response is invalid, it does not bring what is the least necessary evidence to the experts seriously, Even, one of the experts expresses precisely the contrary to your point. Either you just put some names without even checking what was their opinion or you could not understand what they said. That is why is so important to ask for scientific papers, maybe all the experts you think support your opinion are actually doing the opposite, you just could not notice it.

1 ( +2 / -1 )

I forgot to mention that the memory lymphocytes from those who recovered from the 1st SARS CoV (17 years ago) also reacted to the N protein of SARS-CoV-2.

Next, we showed that patients (n = 23) who recovered from SARS (the disease associated with SARS-CoV infection) possess long-lasting memory T cells that are reactive to the N protein of SARS-CoV 17 years after the outbreak of SARS in 2003; these T cells displayed robust cross-reactivity to the N protein of SARS-CoV-2.

https://www.nature.com/articles/s41586-020-2550-z

The article also mentions the following:

We also detected SARS-CoV-2-specific T cells in individuals with no history of SARS, COVID-19 or contact with individuals who had SARS and/or COVID-19 (n = 37)

So many of us are already immune to this virus and we don't know it. It would be great to know who is already immune so we don't need to take any risks with vaccines...

-3 ( +0 / -3 )

I forgot to mention that the memory lymphocytes from those who recovered from the 1st SARS CoV (17 years ago) also reacted to the N protein of SARS-CoV-2.

But to be clear again, those patients are a selection of cases that have this reactivity, not all of the patients that got SARS have this until now. And also all the SARS patients included were heavily symptomatic, so that still says nothing about the immunity for the vast mayority of COVID-19 patients that are never hospitalized. It is still completely possible that only people that required hospitalization have long lasting immunity.

So many of us are already immune to this virus and we don't know it. 

No, that is an unsubstantiated conclusion, many people have reactive cellular immunity against the virus, but that is not the same to be immune. It does indicate some degree of immunity but nobody knows how much nor how effective it is to prevent complications (it may actually work increasing the risk of complications), specially because it targets very different proteins compared with the people that did got COVID-19.

To say those people are protected it is needed to study whether the people with reactive cells show lower rates of complications and death after infection. Until then you can only say they MAY be protected.

1 ( +2 / -1 )

But to be clear again, those patients are a selection of cases that have this reactivity, not all of the patients that got SARS have this until now. And also all the SARS patients included were heavily symptomatic, so that still says nothing about the immunity for the vast mayority of COVID-19 patients that are never hospitalized.

The paper just says that they got samples from 23 people who recovered from SARS-CoV 17 years ago. All of those samples reacted. Where did you get the information that they selected for those who had been heavily symptomatic?

And don't forget:

"We also detected SARS-CoV-2-specific T cells in individuals with no history of SARS, COVID-19 or contact with individuals who had SARS and/or COVID-19 (**n = 37)"**

many people have reactive cellular immunity against the virus, but that is not the same to be immune.

It isn't? What is the difference?

To say those people are protected it is needed to study whether the people with reactive cells show lower rates of complications and death after infection. Until then you can only say they MAY be protected.

I guess the same is true for vaccines. We will only know if vaccines are effective once they show that vaccinated people get less complications and death after infect than recovered people upon reinfection!

it may actually work increasing the risk of complications

Oh, you mean like those previous vaccine candidates that seemed very promising in animal studies but that ended up causing deadly overreactions upon infection.

-3 ( +0 / -3 )

The paper just says that they got samples from 23 people who recovered from SARS-CoV 17 years ago. All of those samples reacted. Where did you get the information that they selected for those who had been heavily symptomatic?

Because that is the default for SARS infection, enough so people with faint or no symptoms are rare enough to be described in case reports like PMC3035549, DPMC7108013 and papers that examine persistance of T-cell activity do it on people that recovered from hospitalization of SARS PMC7115611. There is no need for special selection, SARS do not produce easily asymptomatic infection, so any of such cases being researched specify it because it is the opposite from the normal assumption. Its like "selecting" symptomatic people that got Ebola.

"We also detected SARS-CoV-2-specific T cells in individuals with no history of SARS, COVID-19 or contact with individuals who had SARS and/or COVID-19 (***n* = 37)"*

Which is again not the same as being immune, that is why the cells are described as reactive, but the process is not described as neutralizing. For that more evidence is required.

It isn't? What is the difference?

It should be clear, determination of one single kind of immunity is just a surrogate, it is not the same as being protected. Humoral immunity is the same. For example you can have huge amounts of antibodies against dengue, but if those cause antibody dependent enhancement that still means you will get sick and develop hemorrhagic dengue instead of just the fever.

Its the difference between saying you have antivirus in your computer and saying you are completely protected.

I guess the same is true for vaccines. We will only know if vaccines are effective once they show that vaccinated people get less complications and death after infect than recovered people upon reinfection!

Which is exactly what the later phases of clinical trials do. In this case vaccines that finish such phase by definition have that evidence, people that have reactive T-cells in absence of exposure do not, after they are studied you can say they are protected (if they are) until now that is still only a possibility.

Oh, you mean like those previous vaccine candidates that seemed very promising in animal studies but that ended up causing deadly overreactions upon infection.

Which is exactly why the animal test are done, because thinking that seeing a small window about immunity will let you predict exactly what will happen is deeply antiscientific. So scientists test it and corroborate that there is no problem.

In this case again vaccine have the advantage of having examined this and eliminate it as a realistic risk from the preclinical trials. Which is easily explained by the specific reactivity elicited by the vaccines that mimic exposure to the SARS-CoV-2, different from what is observed on naïve patients.

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