Cellular immunity to SARS-CoV2 found at 6 months in non-hospitalised individuals
uk-cic.org
uk-cic.org
There is a lot of confusion around herd immunity. Think of it more like an equilibrium state than an elimination state. It is where this virus will end up whether we have a perfectly sterilizing vaccine or not.
The thing is, looking at the seasonality of the other strains of coronaviruses, you can see how it kind of looks to what we had this year (only worse as no one was ever infected with this). See Fig. 1 here : https://smw.ch/article/doi/smw.2020.20224
But people do sure like to blame and shame everyone in Europe and the US as if 1 billion people in the Northern hemisphere are somehow all to blame they weren't compliant enough. Viruses will doo what they always did.
China just had an outbreak of hundreds cases in the Uighur region.
What seems more likely: that China has truly "stopped" the virus, and it just re-appeared, miraculously, in one of the most heavily travel restricted places on earth...or that it's actually spreading in China, and testing isn't catching it?
https://www.bbc.com/news/world-asia-china-54687533
Also, you'll note the following quote in the story linked above:
"Asymptomatic cases are not counted in China's official tally of 85,810 confirmed infections."
As for South Korea, it still has regular outbreaks, including some large ones:
https://apnews.com/article/virus-outbreak-pandemics-india-ar...
Taiwan's success at managing the virus has come ~entirely from strict border controls. Being a tiny island nation certainly helps with this. They still have cases, but so far, they're all amongst travelers:
https://time.com/5905129/taiwan-coronavirus-record/
The overall picture here is that some nations have done better than others at controlling the virus (at considerable expense) but almost nobody can claim to have "stopped" it.
-----------
Yet, no lockdown.
No country managed the disease better than Taiwan. We should learn from Taiwan. See [1] for an analysis of Taiwan's response from early March 2020.
It is interesting to reflect upon why most countries ignored Taiwan. The World Health Organization's locking out Taiwan on China's request is probably one reason. Is it the only one?
[1] C. Y. Wang, C. Y. Ng, R. H. Brook, Response to COVID-19 in Taiwan: Big Data Analytics, New Technology, and Proactive Testing. https://pubmed.ncbi.nlm.nih.gov/32125371/
Taiwan is a tiny island, with relatively little international travel (compared to the US, China, etc). If they have no cases internally, and they seal the borders before those cases are introduced, then almost nothing else matters. Small, isolated, island countries can do this -- but even then (i.e. New Zealand) one mistake will mean rapid endemic spread. So sure, as long as Taiwan continues to effectively isolate itself from the outside world, they can probably carry on. But they're not going to: they're already talking about re-establishing travel with the rest of Asia.
It's virtually impossible for a country like the US to do the same thing Taiwan did. Even if we could seal the borders like Taiwan, our population is about 13 times larger, we have large land borders with other countries, and a proportionally large number of expatriate residents with right-of-return. Even with our bans on international travelers, the US has had 6.6 million foreign arrivals in 2020 [1]. Effectively 25% of the entire population of Taiwan has arrived in the US in 2020. And that's just non-citizens.
[1] https://www.trade.gov/visitor-arrivals-program-i-94-data
There is no ‘they are much freer’ argument in the diverse states, because people are dealing with this thing in a huge diversity of ways. Some people have exactly the same life, but they wear a mask, no big deal...
People seem to always assume independent identical random variables. Corona Virus are seasonal - infections highly locally clustered.
The spreading might refuse to follow slow brownian motion of the herd. If e.g. an aircondition blasts an entire room of people with bad air, how much do herd effects really help?
Does the term "herd immunity" make sense for a seasonal virus at all?
Yes. For instance, one of the benefits of widespread flu vaccination is that it slows the rate that the virus spreads at. Herd immunity is just the threshold where enough people have immunity that the spread diminishes. That we don't necessarily reach the threshold doesn't make the lesser effect useless.
So herd immunity is not about immunity. Quite a misnomer then! Always thought herd immunity protected those still vulnerable, but according to you it merely means the vulnerable may merely be having a few more healthy hours falling sick non the less.
Low level zero friction school physics analogy: think of a ball rolling onto an inclined plane. If the plane is angled upwards the ball will slow down and eventually stop rolling further upwards, if the plane is angled downwards it will just continue accelerating forever. But in the upwards case no place on the plane is truly safe from getting reached by the ball, because speed and angle is not specified. Herd immunity means that the slope is upwards, but the velocity would still be an open-ended random distribution.
A more accurate model for virus spread would replace momentum with dice rolls and slope with success thresholds, but that's just more difficult to imagine (unless your biography contains a phase of obsessing over p&p rpg rules).
An individual has immunity when the immune response is triggered. By definition. It was very confusing to me at first before I caught on to the meaning of the term.
It makes sense when you think about it. Can you "get" the virus a second time? Of course of can. That doesn't contradict the fact that you have some level of "immunity".
After all, the immune response is a big part of what most of us feel when getting sick.
Yeah, but this one can cause lasting cardiovascular and nervous system damage in a significant number of people, in addition to permanent lung damage. It's not just another respiratory disease.
https://www.sciencedirect.com/topics/medicine-and-dentistry/...
>In the UK, where it is (often incorrectly) known as ME (myalgic encephalomyelitis), 150 000 people are said to be affected. Other terms used for the condition are postviral fatigue syndrome (PVFS) and chronic fatigue and immune dysfunction syndrome (CFIDS). Symptoms may begin suddenly, sometimes after an acute viral infection, and commonly include incapacitating and persistent fatigue, muscle aches, joint pains, weakness after exercise, headaches, swollen glands, digestive disorders, inability to concentrate, memory loss, recurring minor infections or low-grade fevers, depression, an increasing sense of being unable to function, sleep disturbance, light sensitivity, food intolerance and environmental allergies.
https://www.mayoclinic.org/diseases-conditions/myocarditis/s...
> Viruses. Many viruses are commonly associated with myocarditis, including the viruses that cause the common cold (adenovirus); COVID-19; hepatitis B and C; parvovirus, which causes a mild rash, usually in children (fifth disease); and herpes simplex virus.
Also the 'new' symptoms the long covid sufferers face are often very different to the initial illness - my wifes heart function was impacted hugely, only just starting to recover 7 months later.
What is good is that unlike ME, it appears many of the long covid sufferers are recovering, it just takes a long time, similar to SARs - where as for many ME is a life long condition. So I wouldn't draw to many parallels just yet until we know more.
a) quantification and definition of lasting cardiovascular/ nervous system damage
b) quantification of a significant number of people
c) comparisons to rates comparable to other respiratory diseases (like influenza strains or the bird flu strains etc. )
Understand I ask this not as a coronavirus skeptic, but as a science-literacy proponent who hasn't yet read any reliable source or study for the claim you're making.
The long term studies showing what you are asking are only just starting to show results - but everything we see so far shows that this is causing more issues, in more people than flu.
Also of note, a partner of my wife's friend got covid (positive test) back in April with only light symptoms. Just got it again (tested again) and is very ill this time - had to go to hospital but wasn't kept in. So immunity might not be what we think.
But it's possible to seek out new information on covid, and also to seek to stop spreading disinformation on it, while still accepting its serious nature.
It felt like we spent 3 months trying to convince doctors here that long covid was even a thing, then another couple helping them understand how they can help people like my wife and it is only that last couple of months that there has been a mobilisation of research and interest in this area, so good quality information is currently hard to find.
CoverScan.com moved quite early - https://coverscan.com/news-%26-updates - have done some great work and are starting to release info - my wife was part of the trial. I'm sure there are others, but these things take time.
I'm sure that we will have loads of useful data points next year, but right now even the collection of the data has been poor to understand anything other than just 'deaths' and in some countries 'recoveries' (which was generally just a measure of those that were ill enough to be hospitalised)
To me, it's not the position that Covid has long term effects that's incredulous, because we know that a proportion of a lot of viral infections can develop into longer term complications and effects. But it's the idea/observation that the longer term effects are both comparatively worse than other viruses, and splitting the quantumn of those effects into a "general covid effect" (that is to say, the probability of the effect for a given case of covid), and those of a "general pandemic effect" (that is to say, the population-size effect of having all these infections happening at once due to a relatively vulnerable population with little immunity, in contrast to some of the older/other viruses).
But I admit myself a little more than disturbed how every time I ask to see comparable figures/studies to see how we have knowledge of long-term effects of a virus that's only been around for the short-term, and claims that are usually made without any reference to the viruses to which covid needs to be compared, that I generally get hit by a quick wave of downvotes.
Come join some of the long covid reddit, Facebook, slack or other groups if you want to research first hand - there are plenty out there!
To put it technically, it is "inappropriate to draw substantive conclusions on the basis of a lack of statistically significant effects." You are not proving the null-hypothesis, you are failing to demonstrate the alternative hypothesis.
Or to put it another way, lack of evidence is not evidence that a thing doesn't exist.
My good man, i propose that outside of news stories focusing on relatively small samples and individual case studies, which generally make no comparison to other virus' comparative effects or mention of the biases inherent in their sample, it is no longer being reported because it has not yet been established.
And the reason for this is nothing conspiratorial or denialist, but just due to the fundamentals of good science: that is to say, it's REALLY REALLY hard to accurately establish the long-term effects of a novel virus that has only been around in the human population for the short-term.
If someone proclaims to know the long term effects of a recent novel virus, that's an interesting claim. then they compare the outcomes to other viruses (or declare its fundamentally different), that's also interesting.
I've seen news articles about specific cases, and alarmist tabloid-esque case studies, but as someone who actually reads medical studies, I don't let media or hand-picked cases set my opinion, because in a pandemic with countless millions infected, and with a disease that disproportionately affects co morbid patients, of course one will find individual reports of bad cases and complications. But the information I asked for is presumably the minimum required for your claim to be justified. And if it is so "prevailing", it would be widespread and easily findable, whereas I have yet to see a single source that has them.
Longer term it gets interesting because young people are at a dramatically lower risk of death and older people will have been exposed several times. So, if things go endemic it’s likely for long term annual deaths to be dramatically lower.
PS: The error bars in what you linked are very wide repressing significant uncertainty around those tests.
Herd immunity does not.
So while less virus circulating due to greater population immunity (and therefore lower individual risk of infection) is good, it doesn't help when SARS-CoV-2 does chance into a nursing home.
All of the evidence suggests that immunity against coronaviruses is quite durable.
The only reason that other coronaviruses like OC43 don't kill a lot of people is that almost everyone catches it first as a youth, and builds up a level of immunity. But it can be quite deadly to someone who first catches it later in life, or to immunocompromised patients.
As an aside, OC43 is strongly suspected to be the cause of the 1889-1890 pandemic which killed around 1 million.
Reference: https://english.stackexchange.com/questions/3838/viruses-or-...
It seems atypical for HN-as-usual, but there doesn't even seem to be a pattern to the downvoting.
I understand coronavirus is a hot button topic, but I'm mostly just confused and curious about what's going on.
PS: Obligatory "let's please avoid conjuring coordinated astroturfing campaigns out of thin air to explain" :)
In a nutshell, you can't catch it again right away after having recovered.
"Can't" is too extreme. "Very unlikely" is much more accurate.
So basically only first time you will experience more serious symptoms like a fever, the subsequent infections would be trivial common cold.
We'll see.
They just got very ill again in the last week and tested positive again. Might be totally a-typical or it could just be that we've not seen that many people actually have the chance to catch it twice yet.
Ah! I knew that this was true for the flu, but I always thought there was just a single Common Cold that you could get over and over again. Thanks!
A new coronavirus jumps from an animal to humans. No human body has seen this type of virus before, so when it infects the immune system has to work a lot to learn how to fight it. This causes symptoms like a fever which is a sign of the ongoing struggle. For frail people it means the immune system is not strong enough to counteract the infection and it spreads and potentially kills them.
However, if the immune system learns quickly enough how to fight it, antibodies are killing the virus faster than it can multiply and you get better. The antibodies then disappear in a few months but the long term memory cells remain.
Later, the virus infects you again. You develop the symptoms of a light respiratory infection but the immune system quickly references the memory cells and is able to produce suitable antibodies really fast. The fight is short and easy, the antibodies defeat the virus before it has time to spread. There is no sign of the struggle like first time (no fever) but only the light symptoms we don't even think of (common cold).
Now, how about children? Well as we see already they're unlikely to be seriously affected (low mortality). And children get lots of fevers (parents can confirm). So probably sometimes in the early years we get infected by some coronaviruses our bodies have never seen, the immune system puts up an intense fight and builds the long-term immunity that will be with us as adults.
For SARS-CoV2 and the COVID-19 disease it causes this means that even without the - quite likely - availability of a vaccine over time natural immunity will build up within individuals and the population as a whole, which has the potential of both making the resulting disease less severe and future waves spreading less.
If most individuals who contract the virus during the next few months can't get sick anymore and can't spread the virus anymore for the about 6 months those individuals are taken out of the equation, which leaves less individuals for the virus to spread to in the next wave.
If that's the case, out of curiousity why there has been numerous reported cases of people that catched covid again after already recovering from it?
Edit: So... after reading the article I'm not sure this is the case for all people as this research has been done only on a group of asymptomatic & low/mild response people. IMHO for a sentence like that to be valid, it should be demonstrated on the other part of the population, those that have a high immune response against the virus and end up in a critical state from it.
There have been many, many news articles that speculate about this, but to date, I'm aware of two papers that document re-infections. Both papers isolated and sequenced the viruses involved, and both papers documented re-infection with significantly mutated variants of the same virus.
But which of those will be by majority the study just didn’t investigate.
In immunology no answer is “yes” or “no” but the range. The range is different between different people, and we can conclude what the typical ranges are, if there’s enough data collected. But the ranges are still unknown at the moment.
The same reason (a need to find the ranges) is why you can’t make a vaccine candidate and be sure how it will work, unless you run big and long enough trials. And that’s why that takes time.
Here’s what this study figured out, quoting from the article: “The size of T cell response differed between individuals, being considerably (50%) higher in people who had experienced symptomatic disease at the time of infection six months previously. Further research will be needed to determine the significance of this finding.”
As you see, again some range, but also not concluding what you claim.
The open question is, again, what will be the percentage of such cases.
I don't doubt that reinfection will be rare, at least over the span of a few months, but to my mind that would seem unproven given how hard we're (generally) working to keep people from being infected in the first place.
'Quite high' could mean anything, but if you're implying 'higher than' then that isn't supported by the statistics I've seen in a dozen countries.
No. From the current papers, we just know that the reinfection where people have had their virus sequenced in both first and second infection is very rare.
The problem is technological. Up to now there are around 50 million confirmed cases in the world but probably less than 100 thousand sequencings performed, and only a few sequencings by those who had strong enough symptoms twice and had the chance to have sequencing twice.
Without sequencing one just can’t prove that some case is an actual reinfection. All other cases are just “possible” (i.e. unprovable) reinfections and nobody can claim anything worthy of a scientific paper about them.
There were some suggestions that Covid-19 would be an exception to this somehow, and having recovered, you would still be just as susceptible to getting it again. Which, if it had been true, would have been really bad news, although I suppose it would also have meant there was no reason to wait for a vaccine, because if even the actual virus itself doesn't teach your immune system to look out for it, then there's no way a vaccine could.
But, it's good scientific/medical work to verify that it works like most other viruses, and people who have recovered, are at least almost always going to be resistant thereafter (for at least six months, because that's all the time that has passed yet, although evidence from SARS suggests 10 years or more).
I wouldn't say that completely follows. It would certainly indicate that developing a vaccine would be harder, but not impossible.
Modern vaccine development is essentially fly fishing at this point: the amount of control and options we have with the immune response-generating stimuli exceeds naturally-ocurring scenarios.
As an example, most of the spike-protein-expressing vaccines generate / deliver modified spike proteins, distinct from those found on actual SARS-CoV-2 coronavirus.
It's triggering your immune system to produce and/or store things, the presence of which then confers resistance when subsequently exposed to the actual pathogen.
So from that perspective, the next question is, "Do naturally occurring pathogens, presented in a natural manner, produce an optimal triggering themselves?" To which the answer, as you might guess from the messiness of real-world biology, is "No."
It turns out that while amazing our immune systems are also general purpose and adaptable, and such systems can get confused, or go off on a tangent, or focus on the wrong thing, etc etc.
Vaccines interact with this system by balancing two things: (1) how do I trigger the strongest, purest immune response that's effective on the thing I want to immunize against & (2) how do I avoid triggering such a strong immune response that I convince the body to attack itself?
It turns out, with modern biology, we actually can do better than nature on (1). Even if (2) still requires some guesswork (and a lot of testing).
This is bad news because it means that herd-immunity is not naturally achivable. It means you most get a vaccine at regular intervals to be protected against this strain of the virus.
It also means that lockdown is best strategy to reduce strain on health services until vaccine is ready and freely distributed to all.
Replicated studies have already found that prior exposure to other coronavirus infections (common cold, animal viruses) leaves behind t-cells that are activates for covid-19, as long as 17 years. And that a large percentage of the population has these t-cells. [0]
Does this change your opinion on herd immunity?
It's a shame that the news emphasizes pessimistic headlines and anecdotes over science.
Not much scares me in this life. But just saw my first COVID reinfection this full moon Halloween & I am fucking shook.
20-something yo w/ massive PE, coded, TPA, ECMO in ED, hemorrhage, 3 code carts, methylene blue, PRBCs.
Praying for them and their family And for all of us. https://t.co/T0YqmVxLx8
The language is literally fear mongering. It's not an objective anecdote.
Reinfected! and the reinfection becoming a bad case! No immunity... Article hints that you can expect to be relatively protected for up to 6mo after infection.. But there are no guarantees.
From the article: "There is still a lot for us learn before we have a full understanding of how immunity to COVID-19 works. (..) we all should still follow Government guidelines on social distancing to ensure we play our part in minimising the spread of COVID-19 within our communities." -Professor Paul Moss
NSFW link to twitter:
Not much scares me in this life. But just saw my first COVID reinfection this full moon Halloween & I am fucking shook.
20-something yo w/ massive PE, coded, TPA, ECMO in ED, hemorrhage, 3 code carts, methylene blue, PRBCs.
Praying for them and their family And for all of us. https://t.co/T0YqmVxLx8
https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena...
a) these cases are real and scary
but
b) these cases are proven outliers amplified by crazy fearmongering media and the likes of redditors who don't stop to understand statistics.
What we need is a more reasonable approach to all of this, especially regarding the fact that COVID will be endemic. We need to deal with this fact.
But we also need better reporting since death is not the only bad consequence of COVID-19. It isn't even just limited to health.
Some people die from diseases and some people have long term effects. It's not anything more than a novel virus.
Many of the long term issues described for COVID already messed up my life as a result of Epstein-Barr 14 years ago (brain fog, fatigue). Post-viral syndrome is real and now it's getting some public attention for the first time.
But the other side to this is that if the reinfection is due to the virus mutating into a more virulent state, then it's MORE likely to propagate as that virulent state, meaning more and more COVID19 infected people's will be open to reinfection over time.
Hundreds (thousands?) of healthy people gets the flu in the US every year and die from it. Not because they have a comorbidity, they just have a really bad reaction to the flu.
But we don't assume that those edge cases are the most typical course of disease. Yes, you may be one of those really unlucky ones that die from a normally non-fatal disease, but the risk of that is pretty low.
So as with almost everything nowadays (e.g. look up police brutality statistics and compare to common perception re: pervasiveness), the formula is simple: paint an exciting/horrifying view of reality by sensationalizing rare events.
Way off! Tens of millions catch and tens of thousands die from the flu every single year in the US. And that's with a vaccine! You probably didn't know that though because news stations don't have rolling infection and death counters going 24/7 during flu season.
When I mentioned hundreds or thousands, I'm talking about healthy, young people dying of the flu. It's rare, but it does happen.
My point is that we don't look at those cases and assume that how the flu affects everyone.
Last I read they have 30-40% instance of internal bleeding with many other TERRIBLE things as a side effect of all the blood thinners and other pharmaceuticals needed to use the machine.
I really find it hard to believe that COVID caused the PE, hemorrhage, etc. that ultimately put an end to that young man's life.
Read about it here: https://jamanetwork.com/journals/jamaneurology/fullarticle/1...
ECMO is a hail-mary treatment for people who would almost certainly die otherwise. A 40% chance of death is better than a 99% chance of death.
What you're saying here actually happened with ventilators (though ventilators are nowhere nearly as invasive or complex as ECMO).