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Re:Losing Covid-19 antibody immunity after six months after ... by cat_plus_plus on Thursday September 16, 2021 @01:57AM (#28548547)
Jesus, that's not how immunity works. Your blood is not full of antibodies for every bug you encountered in your lifetime. Mechanisms like memory cells retain knowledge of how to quickly ramp up production if the pathogen is encountered again. They even pre-mutate to anticipate future variants so immunity can get better over time.
Re:Losing Covid-19 antibody immunity after six months after ... by Saptarishi on Thursday September 16, 2021 @02:50AM (#28548843)
I think the point is, the memory cells do not retain this knowledge for extended periods of time in the case of the current Covid vaccines we have. So should we be looking for a 3rd dose, or try to fund a different vaccine?
Re:Losing Covid-19 antibody immunity after six months after ... by rob74 on Thursday September 16, 2021 @03:39AM (#28549120)
Well, that's the question that this study doesn't answer. They (of course) didn't try to infect seniors with reduced antibody response with Covid, they only studied the antibody response in the lab. So the memory cells probably weren't a factor in the lab tests...
Re:Losing Covid-19 antibody immunity after six months after ... by LurkingPenguin on Thursday September 16, 2021 @03:34AM (#28549094)
> I think the point is, the memory cells do not retain this knowledge for extended periods of time in the case of the current Covid vaccines we have.

I didn't see any mention in the article about memory T and B cells. The article only mentions antibodies. Where did you see this?

Re:Losing Covid-19 antibody immunity after six months after ... by Saptarishi on Thursday September 16, 2021 @03:44AM (#28549153)
Antibody remembrance comes from memory cells isnt it? I may be wrong.
Re:Losing Covid-19 antibody immunity after six months after ... by LurkingPenguin on Thursday September 16, 2021 @03:56AM (#28549210)
When you get infected (or vaccinated), your body produces antibodies as part of its primary response. The antibody tests that are commonly done for COVID look for these already circulating antibodies.

Upon infection or vaccination, your body will also produce antibody-producing memory cells to help respond more quickly if you are infected in the future. If you want to test for these memory cells, you can't use antibody tests. You have to use specialized tests that look specifically for the memory cell responses.

There are some commercially available tests, such as https://www.t-detect.com/, which looks at the T cell response.

A lot of the commercially available antibody tests will fail to detect a prior infection after just a few months. T-Detect now says that its test can pick up infections that occurred 10 months ago. 10 months is probably not the limit of detection; it's just based on the amount of time T-Detect has been available to the public.

Researchers have found memory T cells that respond to the original SARS-CoV virus 17 years post-infection:

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

Re:Losing Covid-19 antibody immunity after six months after ... by tzs on Thursday September 16, 2021 @12:37PM (#28553932)
Can any tests distinguish between having a response due to prior infection from having a response due to vaccination?

In the months before I was vaccinated I had on two or three occasions something that felt a bit different from the usual cold/flu/allergies that I get, but was not severe enough to justify trying to get a COVID test. I'm curious if I actually have had COVID or not.

Re:Losing Covid-19 antibody immunity after six months after ... by renewiltord on Thursday September 16, 2021 @04:16AM (#28549298)
Memory cells will produce the antibodies when they are necessary not continuously until the end of time. This paper https://www.medrxiv.org/content/10.1101/2021.08.15.21262067v... just tested to see how many antibodies there are.

It's like saying "All people run out of edible food (antibodies) within hours of being hungry (exposure to distinct protein)". Well, yes, but we have the ingredients to make them in the fridge (memory cells). Just measuring the amount of cooked food (antibodies) will tell you how much I can eat right now, but I'm not going to starve (get sick) in the absence of the cooked food (antibodies) since I have the tools - raw food (memory cells) in case I get hungry (exposed again).

In the case of this study, they tell us we've run out of cooked food in 6 months. That doesn't tell us whether we'll starve, because we could have hella stores in the pantry and they specifically did not measure any of that.

Re:Losing Covid-19 antibody immunity after six months after ... by GeekyBear on Thursday September 16, 2021 @09:00AM (#28551143)
The people who had the original version of SARS 20 years ago, still have an immune response today. Memory cells work just fine.

https://www.nature.com/articles/d41586-021-02260-9

When you encounter the virus again, those with a healthy immune system will ramp up antibody production.

Re:Losing Covid-19 antibody immunity after six months after ... by kjaftaedi on Thursday September 16, 2021 @10:20AM (#28552157)
>the memory cells do not retain this knowledge for extended periods of time in the case of the current Covid vaccines we have

This is a very misinformed statement as this data hasn't been collected yet.

Re:Losing Covid-19 antibody immunity after six months after ... by raducu on Thursday September 16, 2021 @02:33AM (#28548754)
It does for certain bugs/substances, doesn't it, though?

I checked my tetanus antibodies(actually anti-neurotoxin antibodies) recently and they were 5 times over what's considered adequate and I haven't had (at that point) a booster shot in over 20 years.

Re:Losing Covid-19 antibody immunity after six months after ... by dham on Thursday September 16, 2021 @09:55AM (#28551831)
I think other countries (maybe England) are going to start recommending tetanus shot every 30 years. It's probably one of the biggest medical misconceptions that everyone has. The shot lasts for a very long time. Also the chance of getting tetanus is so low for the modern human (that doesn't work on a farm). You basically have to step on glass in soil that has cow feces all over it. Also they try to give you the tetanus shot when you have a deep cut even though it's too late at that point.
Re:Losing Covid-19 antibody immunity after six months after ... by marktucker on Thursday September 16, 2021 @03:17AM (#28549002)
Maybe you had a recent exposure?
Re:Losing Covid-19 antibody immunity after six months after ... by qwerty456127 on Thursday September 16, 2021 @03:41AM (#28549136)
It's been more than a year since I catched what I believe was light covid and periodical tests show my antibodies count never falls and even grows slightly, keeping on the level slightly above what people get after vaccines.
Re:Losing Covid-19 antibody immunity after six months after ... by Kiro on Thursday September 16, 2021 @02:30AM (#28548739)
Yeah, these professors and researchers are clueless. The true experts are random people on Hacker News.
Re:Losing Covid-19 antibody immunity after six months after ... by Aachen on Thursday September 16, 2021 @03:59AM (#28549226)
It wouldn't be the first time research lives in its own little bubble, (dis)proving something different from what the world wanted to know. Here, they looked into X (antibody presence) and people make it into Y (corona protection), so then yeah commenters have remarks.

Edit: I read the paper and it just speaks of humoral immunity. Wikipedia:

> Humoral immunity is the aspect of immunity that is mediated by macromolecules found in extracellular fluids such as secreted antibodies, complement proteins, and certain antimicrobial peptides.

Antibodies I'll get to below. Complement proteins and antimicrobial peptides links go to articles saying they're part of the innate immune system (covid protection is done by the adaptive immune system if I understand it correctly). So antibodies is the relevant part:

> Together with B and T cells, antibodies comprise the most important part of the adaptive immune system. They occur in two forms: one that is attached to a B cell, and the other, a soluble form, that is unattached and found in extracellular fluids such as blood plasma. Initially, all antibodies are of the first form, attached to the surface of a B cell – these are then referred to as B-cell receptors (BCR). After an antigen binds to a BCR, the B cell activates to proliferate and differentiate into either plasma cells, which secrete soluble antibodies with the same paratope, or memory B cells, which survive in the body to enable long-lasting immunity to the antigen.

So B cells (well, some but not all) are responsible for long-term immunity, distinct from antibody levels. An antibody (further up the article) is a Y-shaped cell with receptors on the tips which it uses to bind to and thereby tag pathogens for other parts of the immune system to deal with or to neutralize it directly.

So it doesn't sound to me like the paper talks about how long vaccination has an effect, just how long the Y-shaped receptors are in the blood for. This is the so-manyth research I've seen looking at antibodies rather than memory cells. I'd be curious why, but either way it's an incomplete way of looking at protection.

Re:Losing Covid-19 antibody immunity after six months after ... by rob74 on Thursday September 16, 2021 @03:44AM (#28549150)
I doubt that the professors and researchers are clueless, but I'm not so sure about the people writing articles based on this research. And even these people might not be clueless, they might simply be willing to sacrifice accuracy to get a better headline...
Re:Losing Covid-19 antibody immunity after six months after ... by ghuin on Thursday September 16, 2021 @03:25AM (#28549054)
If this pandemic has taught us anything is that professors and researchers are as clueless as the average online commenter.
Re:Losing Covid-19 antibody immunity after six months after ... by mdp2021 on Thursday September 16, 2021 @04:20AM (#28549327)
Or that communication, journalism and divulgation (explaining to the layman) are immensely inadequate in their current common forms.
Re:Losing Covid-19 antibody immunity after six months after ... by Kiro on Thursday September 16, 2021 @07:14AM (#28550277)
What makes you saying this any better than an antivaxxer saying it?
Re:Losing Covid-19 antibody immunity after six months after ... by KarlKemp on Thursday September 16, 2021 @04:35AM (#28549401)
If that's all you learnt from the pandemic, the professors and researchers have beaten you by orders of magnitudes, again.
Re:Losing Covid-19 antibody immunity after six months after ... by toyg on Thursday September 16, 2021 @03:10AM (#28548963)
The modern web in a nutshell: "We've had enough of so-called 'experts', we know better!".
Re:Losing Covid-19 antibody immunity after six months after ... by rjzzleep on Thursday September 16, 2021 @04:11AM (#28549278)
Jesus, that's not how immunity works either. The immune system isn't one thing that learns and then works. Certain components of it work like that, but certain others do not.

You can't just throw out vague statements like that and pretend it's the truth and fact. There are innate and adaptive components, but even the adaptive components, which you conveniently threw everything under, aren't as simple and straightforward as you make them out to be.

For a very "basic" introduction to the adaptive immune system the wikipedia article has some reference[1].

Part of the whole ordeal about Covid is that the whole adaptive response is nowhere near as clear cut as you make it out to be and any actual epidemiologist agrees with that.

[1] https://en.wikipedia.org/wiki/Adaptive_immune_system