We'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.
Unless 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?
The response to covid19 (e.g. lockdowns and mask mandates) have been very politicised. Other political topics on HN seem to follow similar vote patterns.
Probably 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.
The 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?
More 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.
From 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”
This 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.
Sounds like good news, its observed that 6 months after recovering from SARS-CoV2 viral infection, the immune system in most of recovered people was able to identify and work fight off SARS-CoV2 virus. So if these people get in contact with the virus again, there will be less chance of them getting sick and transmitting it to other people.
I'm not sure if it even counts as "news", but it means that an infected-then-recovered person would be "resistant" for at least six months, which is exactly what the SIR model of infections would suggest.
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).
IANAD, immunity is complicated, and long term immunity after having recovered from CoVID-19 infection is not likely.
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.
This 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.
With 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%.
I've noticed with Covid is that there is a lot of attention to edge cases with folks implying that the scenario is common. That's a very alarmist approach.
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.
Why doesn't anyone question the ECMO machines? I'm definitely no doctor, but as a software engineer if my system failed 30-40% of the time I'd stop using it.
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.
Tens of millions of cases, there are going to be a few outliers. Unless it starts happening at a statistically meaningful rate, these are just unfortunate one-offs.
[+] [-] nradov|5 years ago|reply
[+] [-] goalieca|5 years ago|reply
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
[+] [-] tachyonbeam|5 years ago|reply
[+] [-] chinathrow|5 years ago|reply
[+] [-] macinjosh|5 years ago|reply
[+] [-] ethbr0|5 years ago|reply
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|5 years ago|reply
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[+] [-] BFatts|5 years ago|reply
[+] [-] CyanLite2|5 years ago|reply
[+] [-] everdrive|5 years ago|reply
[+] [-] Wintamute|5 years ago|reply
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[+] [-] Animats|5 years ago|reply
[+] [-] bzb6|5 years ago|reply
[+] [-] BjoernKW|5 years ago|reply
In a nutshell, you can't catch it again right away after having recovered.
[+] [-] dataminer|5 years ago|reply
[+] [-] rossdavidh|5 years ago|reply
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).
[+] [-] testmen|5 years ago|reply
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[+] [-] makach|5 years ago|reply
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.
[+] [-] ruairispain|5 years ago|reply
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
[+] [-] unknown|5 years ago|reply
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[+] [-] CyanLite2|5 years ago|reply
[+] [-] iworkfromhome|5 years ago|reply
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[+] [-] testmen|5 years ago|reply
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[+] [-] macinjosh|5 years ago|reply
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[+] [-] Wintamute|5 years ago|reply
[+] [-] ruairispain|5 years ago|reply
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
[+] [-] nradov|5 years ago|reply
https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena...
[+] [-] jaywalk|5 years ago|reply
[+] [-] refurb|5 years ago|reply
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.
[+] [-] TaupeRanger|5 years ago|reply
[+] [-] phamilton4|5 years ago|reply
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...
[+] [-] thehappypm|5 years ago|reply
[+] [-] mlindner|5 years ago|reply
[+] [-] Reason077|5 years ago|reply
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[+] [-] just-juan-post|5 years ago|reply
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