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I spent 2-3 hours late night reading vaccine stuff instead of going to bed. Might as well share! This is more basic and general stuff, not much about covid.
I'd been thinking that killed-virus and protein subunit vaccines could only stimulate humoral (B-cells, antibodies) immunity, since they just float around in your blood and don't infect cells. I'd not absorbed, or had forgotten, about "antigen-presenting cells" such as dendritic cells, which chew up things they find in your blood and present the fragments to T cells. So you can in fact develop killer T cells even without any cells getting infected! And this says that the killed-virus CoronaVac has lower antibody levels than mRNA vaccines but comparable T cell response.
Given that, and talk of covid vaccines being more robust against severe diseases due to T cells, I wondered if the flu vaccine, famously 'meh' about preventing infection (40-50% even with a good strain match), was better at preventing severe flu disease. Yes, one study found reduction of hospitalization 37% (meh) and reduction of needing ICU 82% (ooh!). So even if you get a flu shot but get actual flu (and not something else that's flu like) you can think of the shot as still giving you an easier time rather than just failing you entirely.
This is a long technical paper on covid infections, but the main note I got out of it was that antibody levels don't correlate with memory T cells, so antibody level decline shouldn't be so alarming. And this mentions recovery in patients who are seronegative -- no antibodies detected.
This letter is by a vitamin D pusher, but mentions published patients who couldn't make antibodies but still survived measles or covid; T cell power!
This notes that antibody decline is normal, to keep our blood from turning into a sludge of antibodies, but the antibodies also become more specific. Some gland holds onto antigens, using it as a school to evolve even better B cells. So "how much antibody in my blood" is less useful than "how much neutralizing power does my blood have". The refining period is also a reason for spacing out doses.
Why do we get colds? AIUI, it notes that the diseases we've mostly stamped out, where herd immunity applies, have to pass through our blood or lymph, getting exposed to the full power of our immune system. Colds basically bounce off the mucosal surfaces in our noses, and humans haven't evolved to maintain full sterilizing power up there. So you get colds because there are 200+ viruses (and the cold symptoms are more your immune system trying to beat off intruders than the viruses themselves all doing the same thing), but also the same virus might get you again a year or two later.
This wonders if "sterilizing immunity" as something we can reliably cause is in fact a myth, with various measles 'breakthroughs' observed (but vaccine still being protective).
Another paper, talking about vaccine effectiveness lifetime; it notes that vaccines requiring multiple doses is the normal, even for most of our 'best' live-virus family. Smallpox turns out to have been easy mode. Like if you look at the CDC schedule, none of them are single dose vaccines, live or not. Yellow fever is, though even that's debated whether you should have a booster for lifetime immunity. The paper also talks about why (graph): again, decline is normal, but full infection angers your immune system so much that the decline is to a protective plateau; even live-virus vaccines are less aggro, and decline to a level that's not fully protective, unless more doses boost the set point.
I'd been thinking that killed-virus and protein subunit vaccines could only stimulate humoral (B-cells, antibodies) immunity, since they just float around in your blood and don't infect cells. I'd not absorbed, or had forgotten, about "antigen-presenting cells" such as dendritic cells, which chew up things they find in your blood and present the fragments to T cells. So you can in fact develop killer T cells even without any cells getting infected! And this says that the killed-virus CoronaVac has lower antibody levels than mRNA vaccines but comparable T cell response.
Given that, and talk of covid vaccines being more robust against severe diseases due to T cells, I wondered if the flu vaccine, famously 'meh' about preventing infection (40-50% even with a good strain match), was better at preventing severe flu disease. Yes, one study found reduction of hospitalization 37% (meh) and reduction of needing ICU 82% (ooh!). So even if you get a flu shot but get actual flu (and not something else that's flu like) you can think of the shot as still giving you an easier time rather than just failing you entirely.
This is a long technical paper on covid infections, but the main note I got out of it was that antibody levels don't correlate with memory T cells, so antibody level decline shouldn't be so alarming. And this mentions recovery in patients who are seronegative -- no antibodies detected.
This letter is by a vitamin D pusher, but mentions published patients who couldn't make antibodies but still survived measles or covid; T cell power!
This notes that antibody decline is normal, to keep our blood from turning into a sludge of antibodies, but the antibodies also become more specific. Some gland holds onto antigens, using it as a school to evolve even better B cells. So "how much antibody in my blood" is less useful than "how much neutralizing power does my blood have". The refining period is also a reason for spacing out doses.
Why do we get colds? AIUI, it notes that the diseases we've mostly stamped out, where herd immunity applies, have to pass through our blood or lymph, getting exposed to the full power of our immune system. Colds basically bounce off the mucosal surfaces in our noses, and humans haven't evolved to maintain full sterilizing power up there. So you get colds because there are 200+ viruses (and the cold symptoms are more your immune system trying to beat off intruders than the viruses themselves all doing the same thing), but also the same virus might get you again a year or two later.
This wonders if "sterilizing immunity" as something we can reliably cause is in fact a myth, with various measles 'breakthroughs' observed (but vaccine still being protective).
Another paper, talking about vaccine effectiveness lifetime; it notes that vaccines requiring multiple doses is the normal, even for most of our 'best' live-virus family. Smallpox turns out to have been easy mode. Like if you look at the CDC schedule, none of them are single dose vaccines, live or not. Yellow fever is, though even that's debated whether you should have a booster for lifetime immunity. The paper also talks about why (graph): again, decline is normal, but full infection angers your immune system so much that the decline is to a protective plateau; even live-virus vaccines are less aggro, and decline to a level that's not fully protective, unless more doses boost the set point.
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Date: 2021-12-21 04:19 (UTC)From: