5 ms·

Sorry I’m not quite sure I follow. You’re saying antibodies are the “quick and easy” way to measure whether a person’s body is (correctly) reacting to the vacci

Sorry I’m not quite sure I follow. You’re saying antibodies are the “quick and easy” way to measure whether a person’s body is (correctly) reacting to the vaccine. So when someone has antibodies soon after vaccination it’s a sign it’s worked, but the antibodies dissipating isn’t necessarily a sign a person no longer has immunity? But since testing for antibodies is the only feasible test available to measure immune response in response to the vaccine it’s become conflated with actual immunity? So someone could (in theory) get the vaccine, have tons of antibodies 6 weeks later, then have greatly reduced antibodies and it doesn’t tell us anything about whether or how much immunity that person will have if they’re infected?

maxerickson 5y ago
More or less. There's cells that remember how to make the antibodies, speeding up the response to a second exposure even long after the initial exposure. Having lots of antibodies when exposed can maybe prevent infection or lessen severity, so it isn't a complete non-concern that they fade.
- rolph 5y ago
  you understand the concept in a practical form
robbiep 5y ago
Someone will have tons of antibodies 4-6 weeks later and then experience a drop off. Especially if you’re measuring from the first vaccine dose. This is literally how the Adaptive immune system works. Initial adaptive response, production of IgM, Vdj recombination, class switching and global proliferation (especially in the face of a repeated antigen insult), followed by a tone down of B cells as the memory effect is preserved and the antibody titre falls back (antibodies have a half life of 3-4 weeks). Because (at least currently) the antibody response in humans is non-sterilising (talk of boosters to generate IgA abound, along with a more specific Delta variant vaccine may change this) you can’t equate a titre in humans yet with a ‘level’ of immunity
- rolph 5y ago
  you as well understand at a deeper level
rolph 5y ago
you seem to understand it correctly, the level of >protection< may be inferred by observing titre of antibodies, the strength of immune response may be inferred by observing increase of titre after challenge by pathogen. the durability of immunity may be inferred by observing the increased response to challenge over points in time.

maxerickson 5y ago

More or less. There's cells that remember how to make the antibodies, speeding up the response to a second exposure even long after the initial exposure. Having lots of antibodies when exposed can maybe prevent infection or lessen severity, so it isn't a complete non-concern that they fade.

rolph 5y ago
you understand the concept in a practical form

robbiep 5y ago

Someone will have tons of antibodies 4-6 weeks later and then experience a drop off. Especially if you’re measuring from the first vaccine dose. This is literally how the Adaptive immune system works. Initial adaptive response, production of IgM, Vdj recombination, class switching and global proliferation (especially in the face of a repeated antigen insult), followed by a tone down of B cells as the memory effect is preserved and the antibody titre falls back (antibodies have a half life of 3-4 weeks). Because (at least currently) the antibody response in humans is non-sterilising (talk of boosters to generate IgA abound, along with a more specific Delta variant vaccine may change this) you can’t equate a titre in humans yet with a ‘level’ of immunity

rolph 5y ago
you as well understand at a deeper level

rolph 5y ago

you seem to understand it correctly, the level of >protection< may be inferred by observing titre of antibodies, the strength of immune response may be inferred by observing increase of titre after challenge by pathogen. the durability of immunity may be inferred by observing the increased response to challenge over points in time.