Starker on 9/12/2021 at 22:46
Another thing to consider, though, is that antibody levels are going to contract eventually, so, in the long perspective, relying on antibodies doesn't seem to be very sustainable. It's not like we can keep giving people booster shots every 6 months.
faetal on 9/12/2021 at 23:09
B cells aren't my speciality (I'm a T cell guy), but I'd have thought that central memory B cells would persist for a while.
I don't think the boosters are a top up of waning immunity so much as a boosting of the initial response (more inflammatory events in conjunction with epitope = shifted balance away from immune tolerance of epitope = more aggressive response).
But again, B cells / antibodies is not something I am have studied much since undergraduate (2007-2009).
lowenz on 9/12/2021 at 23:11
Quote Posted by Starker
Another thing to consider, though, is that antibody levels are going to contract eventually, so, in the long perspective, relying on antibodies doesn't seem to be very sustainable. It's not like we can keep giving people booster shots every 6 months.
We can't but we must :p
About " antibody binding neutralises virus before it infects".....nose and oral mucosa apart. It's why vaccinated people can infect nonetheless (really low rate but it's still possible).
faetal on 9/12/2021 at 23:13
I meant that's what antibodies do to the virus, as in once the virus is in the cell, antibody role is over.
Starker on 10/12/2021 at 00:09
I've been looking into mRNA vaccine boosters recently, because I've been mulling over whether I should try to get a third shot for work-related reasons, but so far, as a layperson, I have had a really tough time making any sense of the reasoning behind them. The second dose is fairly easy to understand -- you get the best response when you have two doses and space them far enough apart, but it's the third dose where opinions in the scientific community seem to vary significantly as to why it's needed or if it's needed at all.
Some people say that unless you are in a risk group (elderly, comorbidities, etc), two doses are enough and third doses are unnecessary (these seem to be mostly the "show me the data" type of scientists).
Some people are saying you should get a third dose just in case (which doesn't seem like a thing a scientist should be saying, but okay, I can get that it's best to err on the side of caution when public health is concerned, even as I wonder whether these shots wouldn't be better served as a first dose in countries that have been struggling to get them).
Some people are saying a third dose is needed because the first two doses weren't spaced apart properly (but even just 2 doses with a few weeks apart seem to be quite effective already, so it's unclear how much the third dose is needed).
Some people are saying you should get a third dose to keep your antibody levels high and avoid any infections, as sterilizing immunity is the best immunity to have (which is the policy that seems to be unsustainable to me in the long run and again makes me wonder whether these shots would be served better elsewhere).
Some people are saying a third dose is needed to reduce the spread of the virus (it's unclear to me how significant the reduction would be, as the two first doses should have reduced the spread already to some extent).
faetal on 10/12/2021 at 00:48
My only comparable experience was skin immunology experiments in mice, where if you didn't get a strong enough allergic response from a single antigen challenge, you challenged again after the refractory period.
More challenges = stronger response, but possibly with diminishing returns leading to an asymptote (or even an undesirably strong response if you have effector T cells killing your own cells).
The reason being that every time you initiate an immune response, you get your antigen-specific T helper cells going in and excreting a bunch of pro-inflammatory cytokines & other chemical messengers to get your effector cells fired up and ready to attack, but there also a non-antigen specific influx of regulatory T cells, which excrete tolerogenic cytokines to try to push for a more tolerogenic effector cell phenotype. The theory being that this constant push-pull between helper cells and regulatory cells will allow a targeted response only when the background milieu of "danger" signals (e.g. from pathogens or tissue damage) is sufficiently high, thus reducing risk of auto-immunity.
So the theory of additional challenges (which with vaccines are usually accompanied with adjuvant and the needle stick injury itself to generate the "danger" signals) is that you keep nudging the overall antigen-specific immune response phenotype away from tolerance, hence a more pronounced response.
This is very back of a napkin and I should disclaim that my specialty is T cell mediated allergic responses in skin, and I haven't worked in the field for over 5 years, so the consensus may have shifted.
Azaran on 10/12/2021 at 00:54
If I had the choice, I'd get a new shot every 4 months or so. As I understand it, antibody immunity peaks at 3 months, and starts waning afterwards. I don't want to catch it, ever, if I can avoid it
Pyrian on 10/12/2021 at 04:58
Quote Posted by Starker
...makes me wonder whether these shots would be served better elsewhere...
I'm pretty sure the shots I and my family get would be better used elsewhere, but I don't have much of a say in elsewhere, I can only control whether we get them.
lowenz on 10/12/2021 at 11:23
Maybe it's time to really engineer the virus and make ourselves a not-harming variant? :D
Starker on 10/12/2021 at 11:32
And hide it in salad dressing?
