5 ms·

> it takes eight times as many antibodies from a vaccinated individual to block the virus If this is the case, then how can we explain how vaccinated individua

by spuz 5y ago

> it takes eight times as many antibodies from a vaccinated individual to block the virus If this is the case, then how can we explain how vaccinated individuals experience less severe symptoms and fewer deaths? Is it because once vaccinated, the immune system is able to respond to this 8x higher demand?

heavenlyblue 5y ago
It does not necessarily mean that virus is 8 times more effective in the general case, just that it takes more resources to battle it.
zamfi 5y ago
Every article that leads with this kind of stat is guilty of lying by omission. The typical immune response produces 10,000-100,000 times more antibodies than “necessary” to fight an infection. If delta needs 8x more antibodies, then, well, our immune response is only overkill by a factor of 1,250-12,500. Perhaps that’s enough for some of the virus to escape. But it’s still plenty to prevent severe illness! Of course, these are just averages, and the 8x number does mean that people who have a depressed immune response are more likely to just not have enough antibody production, though the relationship between “8x” and this response is complex. And in reality, transmission is driven in part by how much viral replication happens before antibodies are generated in large numbers. Delta is also better at this, presumably.
- spuz 5y ago
  That's really interesting, thanks.
  - echelon 5y ago
    The problem is that the immune system is an incredibly complex and dynamical system that almost nobody with only a general biology understanding is equipped to understand. It's even worse if you have no familiarity with biology. Your general bio classes in college gloss over immunology to a point that it's practically a misshapen lie. (Not unlike undergraduate general chemistry.) You have to read and study a lot more to understand and describe the behavior of the system such as the parent poster did. And that's just one small detail in an elaborate series of interacting mechanisms. It's so weird to see the world impacted by something people are ill equipped to understand. And it makes you wonder about all the other crises we deal with where you have absolutely zero bearing for understanding.
    - spuz 5y ago
      In this case, I don't think it's necessary to go into too much detail about how the immune system works. The issue is that if you are going to _some_ level of detail, then you need to include all the relevant context. In this case, the number of antibodies that the immune system can produce goes along way to explain the points made in the rest of the article. PS I am aware how damn complex the immune system is and how complicated it can be to explain to people at the right level of detail. I once attempted to watch a lecture on how the spike protein and antibodies work which went into detail on all the chemical reactions that occur at each step and it is just insane how much complexity there is to it. And that was presumably a simplification of what actually happens.
- alecst 5y ago
  I'm open minded to what you're saying but help me understand how both this > The typical immune response produces 10,000-100,000 times more antibodies than “necessary” to fight an infection. can be true, and how vaccines are basically 90% effective at preventing symptomatic illness (kinda sorta, leaning towards the high end.) Feels like the numbers don't match up.
  - qzw 5y ago
    Both can be true if ~10% of the population do not have a "typical immune response" to the vaccine. This can be due to a number of factors such as age, preexisting conditions, general health, etc. Plus the immunity from vaccination "wears off" over time, and some of the earliest recipients are now 8+ months post vaccination.
  - zamfi 5y ago
    The short answer to your question is that it takes time to mount an antibody response. Vaccines do one big thing: they "teach" the adaptive immune system how to produce antibodies for the virus, and in the process the body produces a ton of antibodies, which fade over time. The antibodies fade quickly-ish (months), the "learning how to make antibodies" fades much more slowly, if at all (decades). 1) You get symptoms if you don't have enough antibodies in the right place when the infection comes in. 2) You avoid severe illness if your body can produces enough new antibodies (if it doesn't have enough) fast enough before the virus infects the really vulnerable parts of you. People who have symptomatic breakthrough infections probably didn't have enough antibodies left in their noses to counter the initial infection, but are able to very rapidly mount a new antibody response so they don't get sicker. The initial 100,000x overkill is full-body, and fades over time. Months later, a vaccinated person might not have enough antibodies floating around in their nose to completely neutralize an airborne bubble with 10,000 virus on it landing inside. As someone else implied elsewhere, the immune system is super complex. I'm going to attempt an ELI15 here. Apologies in advance for the wall of text. == A Story == There are two parts to the immune response, called "innate" and "adaptive". The innate response are first responders. They kick in as soon as they notice the "wrong" thing floating around in your nose/airway/lung cells. This response produces the early symptoms associated with respiratory infections: inflammation, sneezes, coughs, sore throats, runny noses, fevers, etc. It's trying to get as many of the body's white blood cells (immune cells) into the area as possible to clear out this virus that is simultaneously infecting cells and reproducing like crazy: doubling every 20 minutes; by the time the innate system kicks in, your hijacked airway cells have probably produced millions of new virus already. The more virus, the stronger the innate response: more immune cells, more killing infected cells, more clearing of cellular debris, etc. Your nose is runny, your throat is inflamed, etc. -- it's a huge battle, with millions of your cells fighting billions of virus. The best they can do is try to stem the tide, and they very likely won't win on their own. Fortunately for you, during all this, some of your cells take parts of the virus, and present it to the cells responsible for the adaptive immune response. These are the scientists sitting in the back lab figuring out how to produce "antibodies" -- these are the red shells in MarioKart. They are designed specifically to latch on to and inactivate the invading virus, and make it super easy for the rest of the immune cells in your body to recognize the virus as foreign and destroy it. Designing these antibodies takes some time, unfortunately, and meanwhile there's a huge battle going on for your airways. Antibodies are HARD to design: you want something that attacks ONLY the virus, and not, say, also your pancreas by accident, because then you get Type 1 diabetes, and, well, that's not so great. There is a lot of time pressure, because the virus is winning, and if the back lab scientists have never seen anything like this virus before, designing the antibodies can take days, maybe even a week or more, and then producing them in mass quantities takes days longer. The virus could overwhelm the body in the meantime. BUT! But, if your adaptive immune system's scientists have seen the virus before, say because you were vaccinated -- a process in which your immune system was presented with a bunch of parts of virus that were taken to the back lab and the scientists designed antibodies for it, WITHOUT the time pressure of an actual infection -- then they basically have blueprints ready to go. (Less time spent coming up with plans means less time for the virus to overwhelm you.) Now, regardless of where your adaptive immunity learned to make antibodies, when your body is ready, it goes to TOWN: we are talking trillions of antibodies produced in days, they literally flood your whole body. At peak there could be hundreds of thousands of antibodies for every virus particle. At this point, unless the virus figures out a way to hide from antibodies, it has more or less no chance. It's over. You've won. Your body will still need to clear the battlefield, so you may still have symptoms for a bit while this happens. For vaccinated folks, there may even still be antibodies floating around from the vaccine, making everything much easier. There may be so many antibodies floating around that the virus doesn't even stand a chance -- it gets neutralized really fast (and transmission is blocked); there may just be a few antibodies around, but the adaptive response kicks in fast (mild symptomatic illness) and wipes the floor a few days later. I hope this helps paint the big picture (with timelines) of what happens when a virus lands in your nose. I'm sure the HN crowd can imagine all sorts of edge cases here, and when hundreds of millions of people are infected with a single virus, basically any edge case with probability greater than 1e-6 is going to happen >100 times.
s1artibartfast 5y ago
This is in comparison to the Alpha variant. Better quote: >compared with the Alpha variant - in other words, it takes eight times as many antibodies from a vaccinated individual to block the virus. Needing 8 times the antibodies int a problem if you have anitbodies to spare. Most vaccinated people do, but not all, depending on their immune system, exposure level, and vaccine reaction. This is why we see only slightly lower efficacy for the vaccine against Delta vs Alpha, not an 8X reduction in efficacy.
rspeele 5y ago
The specific part you excerpted, by itself, is confusing. When I read just your comment, having not read the article, I interpreted it as: "it takes eight times as many antibodies from a vaccinated individual to block the virus [compared to an unvaccinated individual]" When I went to find the excerpt within the article, I realized in context it meant: "it takes eight times as many antibodies from a vaccinated individual to block the [delta variant] virus [compared to blocking the alpha virus]" And separately offers the information that for antibodies from natural immunity, the difficulty jump from alpha to delta is 5.7x instead of 8x. Which would suggest that having natural immunity could be better than having only vaccine immunity, but definitely doesn't suggest that being unvaccinated is better than being vaccinated. So there's no mystery for vaccinated individuals having better odds against COVID than unvaccinated ones.

by spuz 5y ago

heavenlyblue 5y ago

It does not necessarily mean that virus is 8 times more effective in the general case, just that it takes more resources to battle it.

zamfi 5y ago

Every article that leads with this kind of stat is guilty of lying by omission. The typical immune response produces 10,000-100,000 times more antibodies than “necessary” to fight an infection. If delta needs 8x more antibodies, then, well, our immune response is only overkill by a factor of 1,250-12,500. Perhaps that’s enough for some of the virus to escape. But it’s still plenty to prevent severe illness! Of course, these are just averages, and the 8x number does mean that people who have a depressed immune response are more likely to just not have enough antibody production, though the relationship between “8x” and this response is complex. And in reality, transmission is driven in part by how much viral replication happens before antibodies are generated in large numbers. Delta is also better at this, presumably.

spuz 5y ago
That's really interesting, thanks.
- echelon 5y ago
  The problem is that the immune system is an incredibly complex and dynamical system that almost nobody with only a general biology understanding is equipped to understand. It's even worse if you have no familiarity with biology. Your general bio classes in college gloss over immunology to a point that it's practically a misshapen lie. (Not unlike undergraduate general chemistry.) You have to read and study a lot more to understand and describe the behavior of the system such as the parent poster did. And that's just one small detail in an elaborate series of interacting mechanisms. It's so weird to see the world impacted by something people are ill equipped to understand. And it makes you wonder about all the other crises we deal with where you have absolutely zero bearing for understanding.
  - spuz 5y ago
    In this case, I don't think it's necessary to go into too much detail about how the immune system works. The issue is that if you are going to _some_ level of detail, then you need to include all the relevant context. In this case, the number of antibodies that the immune system can produce goes along way to explain the points made in the rest of the article. PS I am aware how damn complex the immune system is and how complicated it can be to explain to people at the right level of detail. I once attempted to watch a lecture on how the spike protein and antibodies work which went into detail on all the chemical reactions that occur at each step and it is just insane how much complexity there is to it. And that was presumably a simplification of what actually happens.
alecst 5y ago
I'm open minded to what you're saying but help me understand how both this > The typical immune response produces 10,000-100,000 times more antibodies than “necessary” to fight an infection. can be true, and how vaccines are basically 90% effective at preventing symptomatic illness (kinda sorta, leaning towards the high end.) Feels like the numbers don't match up.
- qzw 5y ago
  Both can be true if ~10% of the population do not have a "typical immune response" to the vaccine. This can be due to a number of factors such as age, preexisting conditions, general health, etc. Plus the immunity from vaccination "wears off" over time, and some of the earliest recipients are now 8+ months post vaccination.
- zamfi 5y ago
  The short answer to your question is that it takes time to mount an antibody response. Vaccines do one big thing: they "teach" the adaptive immune system how to produce antibodies for the virus, and in the process the body produces a ton of antibodies, which fade over time. The antibodies fade quickly-ish (months), the "learning how to make antibodies" fades much more slowly, if at all (decades). 1) You get symptoms if you don't have enough antibodies in the right place when the infection comes in. 2) You avoid severe illness if your body can produces enough new antibodies (if it doesn't have enough) fast enough before the virus infects the really vulnerable parts of you. People who have symptomatic breakthrough infections probably didn't have enough antibodies left in their noses to counter the initial infection, but are able to very rapidly mount a new antibody response so they don't get sicker. The initial 100,000x overkill is full-body, and fades over time. Months later, a vaccinated person might not have enough antibodies floating around in their nose to completely neutralize an airborne bubble with 10,000 virus on it landing inside. As someone else implied elsewhere, the immune system is super complex. I'm going to attempt an ELI15 here. Apologies in advance for the wall of text. == A Story == There are two parts to the immune response, called "innate" and "adaptive". The innate response are first responders. They kick in as soon as they notice the "wrong" thing floating around in your nose/airway/lung cells. This response produces the early symptoms associated with respiratory infections: inflammation, sneezes, coughs, sore throats, runny noses, fevers, etc. It's trying to get as many of the body's white blood cells (immune cells) into the area as possible to clear out this virus that is simultaneously infecting cells and reproducing like crazy: doubling every 20 minutes; by the time the innate system kicks in, your hijacked airway cells have probably produced millions of new virus already. The more virus, the stronger the innate response: more immune cells, more killing infected cells, more clearing of cellular debris, etc. Your nose is runny, your throat is inflamed, etc. -- it's a huge battle, with millions of your cells fighting billions of virus. The best they can do is try to stem the tide, and they very likely won't win on their own. Fortunately for you, during all this, some of your cells take parts of the virus, and present it to the cells responsible for the adaptive immune response. These are the scientists sitting in the back lab figuring out how to produce "antibodies" -- these are the red shells in MarioKart. They are designed specifically to latch on to and inactivate the invading virus, and make it super easy for the rest of the immune cells in your body to recognize the virus as foreign and destroy it. Designing these antibodies takes some time, unfortunately, and meanwhile there's a huge battle going on for your airways. Antibodies are HARD to design: you want something that attacks ONLY the virus, and not, say, also your pancreas by accident, because then you get Type 1 diabetes, and, well, that's not so great. There is a lot of time pressure, because the virus is winning, and if the back lab scientists have never seen anything like this virus before, designing the antibodies can take days, maybe even a week or more, and then producing them in mass quantities takes days longer. The virus could overwhelm the body in the meantime. BUT! But, if your adaptive immune system's scientists have seen the virus before, say because you were vaccinated -- a process in which your immune system was presented with a bunch of parts of virus that were taken to the back lab and the scientists designed antibodies for it, WITHOUT the time pressure of an actual infection -- then they basically have blueprints ready to go. (Less time spent coming up with plans means less time for the virus to overwhelm you.) Now, regardless of where your adaptive immunity learned to make antibodies, when your body is ready, it goes to TOWN: we are talking trillions of antibodies produced in days, they literally flood your whole body. At peak there could be hundreds of thousands of antibodies for every virus particle. At this point, unless the virus figures out a way to hide from antibodies, it has more or less no chance. It's over. You've won. Your body will still need to clear the battlefield, so you may still have symptoms for a bit while this happens. For vaccinated folks, there may even still be antibodies floating around from the vaccine, making everything much easier. There may be so many antibodies floating around that the virus doesn't even stand a chance -- it gets neutralized really fast (and transmission is blocked); there may just be a few antibodies around, but the adaptive response kicks in fast (mild symptomatic illness) and wipes the floor a few days later. I hope this helps paint the big picture (with timelines) of what happens when a virus lands in your nose. I'm sure the HN crowd can imagine all sorts of edge cases here, and when hundreds of millions of people are infected with a single virus, basically any edge case with probability greater than 1e-6 is going to happen >100 times.

s1artibartfast 5y ago

This is in comparison to the Alpha variant. Better quote: >compared with the Alpha variant - in other words, it takes eight times as many antibodies from a vaccinated individual to block the virus. Needing 8 times the antibodies int a problem if you have anitbodies to spare. Most vaccinated people do, but not all, depending on their immune system, exposure level, and vaccine reaction. This is why we see only slightly lower efficacy for the vaccine against Delta vs Alpha, not an 8X reduction in efficacy.

rspeele 5y ago

The specific part you excerpted, by itself, is confusing. When I read just your comment, having not read the article, I interpreted it as: "it takes eight times as many antibodies from a vaccinated individual to block the virus [compared to an unvaccinated individual]" When I went to find the excerpt within the article, I realized in context it meant: "it takes eight times as many antibodies from a vaccinated individual to block the [delta variant] virus [compared to blocking the alpha virus]" And separately offers the information that for antibodies from natural immunity, the difficulty jump from alpha to delta is 5.7x instead of 8x. Which would suggest that having natural immunity could be better than having only vaccine immunity, but definitely doesn't suggest that being unvaccinated is better than being vaccinated. So there's no mystery for vaccinated individuals having better odds against COVID than unvaccinated ones.