mRNA vaccines are a new invention, so that line of reasoning isn’t particularly reassuring.
Protection has shifted from protection against infection to infection against severe outcomes because of antigenic drift: the vaccines are most closely targeted to the ancestral strain. That match is most important for antibody protection: since antibodies are critical to protection against infection, the vaccines produce significantly less protection against infection as the virus drifts further from the ancestral type. T cell immunity is less affected by antigenic drift, so their protection against severe disease isn’t as attenuated.
An extremely helpful paragraph, which taught me several things I’m embarrassed not to have known; that’s worth a strong upvote by itself.
ADE is a real thing, and it was a concern early on. In particular, there was a feline coronavirus vaccine some years ago that triggered ADE, so there was concern that covid might have similar issues. But we’ve seen no sign of that.
In retrospect, I can see how I gave the impression that ADE was the main concern, instead of just the worst-case scenario; that’s my bad. The scenario that seems not-vanishingly-unlikely to me is unprecedentedly homogenous immune responses incentivizing unprecedentedly rapid antigenic drift, until patients end up with immune responses (enshrined by antigenic sin) less effective than what their bodies would have come up with by themselves. I’ll edit the OP to clarify.
Thank you for expaining the shift in protection, and for getting me to make the OP clearer. You’ll definitely get to allocate part of the $2k; I’ll figure out how much after more people have had a chance to provide answers.
mRNA vaccines are a new invention, so that line of reasoning isn’t particularly reassuring.
An extremely helpful paragraph, which taught me several things I’m embarrassed not to have known; that’s worth a strong upvote by itself.
In retrospect, I can see how I gave the impression that ADE was the main concern, instead of just the worst-case scenario; that’s my bad. The scenario that seems not-vanishingly-unlikely to me is unprecedentedly homogenous immune responses incentivizing unprecedentedly rapid antigenic drift, until patients end up with immune responses (enshrined by antigenic sin) less effective than what their bodies would have come up with by themselves. I’ll edit the OP to clarify.
Thank you for expaining the shift in protection, and for getting me to make the OP clearer. You’ll definitely get to allocate part of the $2k; I’ll figure out how much after more people have had a chance to provide answers.