17 ms·
Cellular immunity to SARS-CoV2 found at 6 months in non-hospitalised individuals
- nradov 6y agoSo as expected the immune system response is the same as with other coronaviruses.
- macinjosh 6y agoWho would have thunk it!?
- neuronic 6y agoYea it was likely but that's different from certain. So why this snarky comment? Do you feel superior to the world now?
- goalieca 6y agoWe've found pre-existing T-cell immunity in many individuals (cross-protection from other coronaviruses?) so even if we don't have long-term perfectly sterilizing immunity, the odds are stacked in favour of this becoming just another winter respiratory disease once some level of herd immunity kicks in. 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. https://www.bmj.com/content/370/bmj.m3563 https://www.bmj.com/content/370/bmj.m3563
- Retric 6y agoAn effective vaccine in the near future is a much better option than natural herd immunity due to the lives lost. 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.
- ethbr0 6y agoAs you noted, a vaccine allows us to target immunity, typically by risk profile, as we currently do with common cold viruses. 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.
- WildParser 6y agoYeah, the mathematics around herd immunity are often misused. 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?
- 6y ago
- chinathrow 6y agoUnless it isn't. I thought that ~15% of common cold infections come from Coronavirii - wouldn't that imply that these 15% should cease to exist at a point in time?
- anoncake 6y agoThere are a lot of different strains causing the common cold.
- nradov 6y agoIt wouldn't imply anything of the sort. It's rare for a single viral infection to cause life long sterilizing immunity. Reinfections are possible with most viruses, including other coronaviruses. As long as your immune system is otherwise healthy the memory T cells will kick in and symptoms will usually be less severe. 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. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7252012/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7252012/
- brmgb 6y ago> 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.
- asaph 6y agoThe plural of virus is viruses, not virii. Reference: https://english.stackexchange.com/questions/3838/viruses-or-virii https://english.stackexchange.com/questions/3838/viruses-or-...
- pertymcpert 6y agoViruses.
- tachyonbeam 6y agoWhat is the immune response to other coronaviruses like? How long can we expect people to stay immune to a given strain?
- jandrewrogers 6y agoPeople still have a strong immune response in 2020 for the original 2003 SARS virus. This is consistently the case every time they do a study of 2003 SARS immunity, including the new study a few months ago. Many people with 2003 SARS immunity also show significant immune cross-reactivity with 2019 SARS. All of the evidence suggests that immunity against coronaviruses is quite durable.
- petre 6y agoThen why the reinfections? People still too weak after the initial infection? Different strains? I just want to understand but it's probably still puzzling doctors and virologists.
- tachyonbeam 6y agoAFAIK there have been very few reinfections. Humans have very diverse genes and over 47 million people have been infected. It's entirely normal that there will be outliers whose immune system doesn't produce a response that lasts as long. The rest is the media engaging in fearmongering.
- SomeoneFromCA 6y agoThere is absolutely no way one can claim "strong immune response in 2020 for the original 2003 SARS virus" unless it was actually verified by reinfection. I am aware of the article claiming that there is some kind cellular reaction to SARS, but first of all, it might be not enough at all to protect from reinfection, and secondly, it might be case of well documented cross-immunity from some common cold viruses.
- bzb6 6y agoIs this good or bad news?
- BjoernKW 6y agoThis is good news because it suggests that immunity for SARS-CoV2 isn't worse than that for other coronaviruses (e.g. those causing the common cold), even for those individuals who didn't become so sick they had to be hospitalised. In a nutshell, you can't catch it again right away after having recovered.
- acqq 6y agoNo honest scientist would say what you wrote as your “nutshell.” Specifically, T cell response is not equivalent at all to “you can’t catch it.” Still all scenarios are possible: 1) you can still catch it, and still get more sick 2) you can catch it, and be less sick 3) you can be “sterilizingly immune” meaning that you won’t get sick and won’t be able to transmit to somebody else. 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.
- Robotbeat 6y agoWe have been running a "natural" trial on millions of people. From that, we can already tell that reinfection, although possible, is very rare.
- 6y ago
- testmen 6y agovote for biden, save the country!
- macinjosh 6y agoSeriously, he has been wrong too many times.
- deleted 6y ago[deleted]
- ruairispain 6y agoHere's a doctor's tweet from today about a young male that got reinfected after 7 months. EcMO machine, full bipass and 3 heart restarts. 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://t.co/T0YqmVxLx8
- jaywalk 6y agoYeah, looking at more of his tweets, that guy seems like a Covid fear monger.
- craftinator 6y agoUnless you're the person who has a second infection or the doctor who has to deal with this life and death situation, then yeah, fear mongering... 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.
- ethbr0 6y agohttps://nextstrain.org/sars-cov-2 https://nextstrain.org/sars-cov-2
- nradov 6y agoWith millions of cases worldwide there will always be some statistical outliers. Those are individually tragic, but not very relevant to most of us. The best estimate for infection fatality rate in the 20 - 49 age group is only 0.02%. https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena...
- neuronic 6y ago
- iworkfromhome 6y agoReported by By Maggie Fox, CNN Updated 7:55 AM EDT, Wed October 14, 2020 "New reports show coronavirus immunity can last for months" Three new reports show coronavirus immunity can last for months -- and maybe even longer. The findings suggest that many, if not most, people who recover from coronavirus infections are protected for at least a period of time. They also suggest that coronavirus vaccines may be able to protect people for more than just a few weeks. One study found that people produce antibodies that protect against infection and last for at least five to seven months. http://cnn.com.via.snip.ly/t2azqx http://cnn.com.via.snip.ly/t2azqx
- CyanLite2 6y agoThis is great news for vaccines.
- BFatts 6y agoThe title seems misleading to me. Does the fact that "...blood samples from a cohort of more than 2,000 clinical and non-clinical healthcare workers..." might seem to indicate a near-constant exposure to SARS-cov-2? That might increase the chance that the individual is re-exposed and thus his or her immune system has continual "boosts". It seems noteworthy and something worth investigating. Would this apply to the population at large who do not risk continuous exposure?
- CyanLite2 6y agoPotentially, but the major mRNA vaccines are requiring booster shots 4 weeks apart.
- everdrive 6y agoHow long can immunity typically last? Is 6 months some sort of specific break point, or has it simply been that six months have elapsed?
- Wintamute 6y agoMore likely it's because 6 months have elapsed. Cellular immunity to SARS-COV-1 (2003 outbreak) is still robust 17 years later - the two coronaviruses are fairly similar.
- SomeoneFromCA 6y agoPeople keep parroting that article. "Cellular immunity" mentioned in it may be not enough at all to prevent reinfection. Unless there is a direct rechallenge with the SARS-1 virus someone who already had it in 2003, there is no way to make such a strong statement. Good luck finding volunteers.
- Wintamute 6y agoIt's amusing how you put "cellular immunity" in scare quotes. It's not a new or novel concept, but an extremely well understood mechanism that has been taught to immunology first years for decades. That a coronavirus should exhibit a cellular immune response should be the baseline assumption, rather than the inverse.
- sieabahlpark 6y agoLearn how the immune system works in general. It comes down to having t cells which memorize diseases so you can flood your system with defenses. The difference is over time of fighting it (unless it's constantly present) the antibodies die down (because no need to make more if it's not around to begin with)
- spfzero 6y agoFrom the article, it seems like the latter. They tested at 6 months. If they test those same people again later, then we will possibly have a new high-water mark for the duration of immunity. For now, we can only say “at least 6 months”
- ethbr0 6y ago[Meta] What's up with the upvoting / downvoting in the comments on this article? 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" :)
- La1n 6y agoThe response to covid19 (e.g. lockdowns and mask mandates) have been very politicised. Other political topics on HN seem to follow similar vote patterns.
- sieabahlpark 6y agoJust consider every upvoted item to be a combination of actual people and what some large actors want you to see. HN is no different from reddit at the end of the day.
- petre 6y agoProbably just people getting radicalised with all sorts of ideas, maybe due to imperfect information, lots of misinformation, the topic being politicised, people being stressed because of the pandemic and its consequences. It's not only this topic, I've noticed it in any other less polarising ones as well.
- Wintamute 6y agoThis is great and all, but I'd be interested what proportion of the entire cohort demonstrated a T-cell immune response, not just the 100 who tested sero-positive for SARS-COV-2. There is growing speculation that a significant minority of people may mount a T-cell immune response without ever contracting SARS-COV-2 itself, based on exposure to other coronaviruses. This would be great news since it further reduces the effective threshold for endemic equilibrium.
- Animats 6y agoOK, 6 months. In 6 more months, we'll have data for 12 months.