141–150 of 161 posts
Earlier quoted context omitted.
I have seen speculation that the second dose was given too quickly.
Given how quickly the virus mutates, giving it less frequently makes even less sense.
Anecdotal but I currently have Omicron. I had COVID in March 2021 and got vaccinated in September. I have no symptom except back pain.
I'm fighting it right now myself. Have my initial vaccines and got my booster about a month and a half ago. First two days were terrible, but now it just feels like a cold. What I can't handle is the brain fog. I've been awake enough to do some last minute code reviews for people before we start the Christmas shutdown and they have taken me double/triple the amount of time they usually take me. Answers to questions d…
So like a common cold?
Earlier quoted context omitted.
This, a million times. Over here 80-90% of Covid patients in ICUs are either never vaccinated or in need of a boost because of too much time past since their 2nd shot. So, yes, vaccination may not prevent being infected, but for sure it helps immensely in avoiding being hospitalized and shortening the infection, which does actually translate in less people being infected. And believe me, having both lived and seen th…
>So, yes, vaccination may not prevent being infected, but for sure it helps immensely in avoiding being hospitalized and shortening the infection, which does actually translate in less people being infected. On the flip side, infections in the vaccinated who are asymptomatic are more likely to leave the house, simply because they have no idea that they're sick. Perhaps they end up at a restaurant with their mask off…
The household attack rate of ultimately asymptomatic infections is much lower than ultimately symptomatic. The window for vaccinated people is also shorter since mRNA loads peak at about the same levels (where the entry criteria for the study was the same level of symptomology) but they decline faster and have less culturable, infectious virus for the same level of mRNA load.
And delta already spikes viral loads much, much higher in the presymptomatic phase of an infection (doesn't matter if its naive, breakthrough or reinfection) so that people are walking around spreading it before they know they have it. That ship already sailed.
Once someone is infected, then its better that they get less symptoms and less viral load / less shedding and that they're vaccinated.
It's worth clarifying: un-boosted vaccination or past infection seem to have greatly reduced ability to prevent infection with Omicron. There is still substantial (lessened, but not as drastically lessened) protection against serious illness / death. My understanding is that protection-against-infection and protection-against-death rely on different aspects of the immune system. The primary protection against initial…
I think it's more like, after a vaccination or infection you're now producing 20 different antibodies targeting different sites on the Covid spike. You start out producing high levels of the antibodies and less over time, but when you encounter the same virus you ramp up production of all 20 if your levels weren't high enough to prevent infection in the first place. With Omicron maybe only few of those antibodies sti…
There's something on the order of 1,000 T-cell epitopes against spike, not just 20, and some of them are densely packed in areas of the spike protein that are highly conserved.
The spike is cleaved by proteosomes into small segments and those segments are attached to MHC-I in the ER and then shipped off to be expressed on the cell-surface to be identified by T-cell receptors. Those segments are long enough to be recgonized, but small enough that there's a ton of them (and since they're cleaved an no longer attached to the rest of the protein there's no steric hindering or conformation changes or any of that to worry about). And there's still about 80% overlap between Omicron and Delta/Wuhan-hu-1. That number will probably never get down to zero due to the highly conserved areas.
CD4+/CD8+ T-cells will therefore still be able to identify infected cells and lyse them or drag them back to have a discussion with some memory B-cells. That is where somatic hypermutation might be important since some of those antibodies will match Omicron's spike and those B-cells can then be amplified and you can get Omicron-specific antibodies being produced -- all without having to start entirely from scratch.
But its the CTLs that already identify the Omicron-infected cells which will do the bulk of responding to the virus and clearing the infection. This is also why we don't need to rush to update vaccines to be Omicron-specific or why neutralizing abs really matters that much at all (and if there's Original Antigenic Sin it really may not matter much at all since there may not be much Omicron-specific B-cell or Nabs response to an infection or variant-specific vaccination at all).
> SARS-CoV-2 human T cell epitopes: Adaptive immune response against COVID-19
> Over the past year, numerous studies in the peer reviewed and preprint literature have reported on the virological, epidemiological and clinical characteristics of the coronavirus, SARS-CoV-2. To date, 25 studies have investigated and identified SARS-CoV-2-derived T cell epitopes in humans. Here, we review these recent studies, how they were performed, and their findings. We review how epitopes identified throughout the SARS-CoV2 proteome reveal significant correlation between number of epitopes defined and size of the antigen provenance. We also report additional analysis of SARS-CoV-2 human CD4 and CD8 T cell epitope data compiled from these studies, identifying 1,400 different reported SARS-CoV-2 epitopes and revealing discrete immunodominant regions of the virus and epitopes that are more prevalently recognized. This remarkable breadth of epitope repertoire has implications for vaccine design, cross-reactivity, and immune escape by SARS-CoV-2 variants.
https://www.sciencedirect.com/science/article/pii/S193131282...
Earlier quoted context omitted.
Yes, get it ASAP. You should not assume that you'll get it that soon and therefore it's pointless even if many many people will. The booster also triggers a secondary immune response which rises faster and bigger than the primary response. Get your boosters ASAP! You want to go into this crisis with shields up, weapons online.
I was going to get my UK booster yesterday, but came down with COVID on Tuesday :( Yeah feeling pretty ill right now. Rescheduled booster for early Jan, so hopefully that'll mean my immune system will be ready for any future infections.
It's worth clarifying: un-boosted vaccination or past infection seem to have greatly reduced ability to prevent infection with Omicron. There is still substantial (lessened, but not as drastically lessened) protection against serious illness / death. My understanding is that protection-against-infection and protection-against-death rely on different aspects of the immune system. The primary protection against initial…
There seems to be data from UK that two doses of type-X vaccine followed by a booster of type-Y vaccine being more effective against Omicron.
Different types of vaccines platforms being mRNA vaccines(Pfizer, Moderna etc.), Inactivated whole virus vaccines(CoVaxin,CoronaVac etc.), Pure DNA Vaccine(Zydus), DNA vector vaccines(Astrazenica/Covishield etc.) and upcoming protein subunit vaccines.
Anecdotal but I currently have Omicron. I had COVID in March 2021 and got vaccinated in September. I have no symptom except back pain.
I thought I escaped it by isolating from my wife/son in our home but I started to show early symptoms Wednesday morning waking up with splitting headache. I went and got tested that afternoon. By Thursday night I was having itchy throat, chills, fatigue and body aches. Feeling pretty crappy and a crazy symptom I also have been having is uncontrollable hiccups past 24 hours that come and go.
The test I took Wednesday came back negative but the OTC Rapid I did today was positive. I am going for another PCR tomorrow to confirm as the first one was done possibly too early after exposure with no symptoms.
IF this is the Omicron that went through our vaccinated group like butter, we are going to be in a very bad spot by mid-january.
Earlier quoted context omitted.
From what I understand it is about affinity maturation. Basically, when you get an initial vaccine (or infection) your immune system learns how to recognize the antigen (the virus spike protein) and produces a bunch of antibodies to recognize it. But your immune system also preserves the spike protein in antigen presenting cells so it can continue to produce antibodies to recognize more features of the spike protein.…
> So when you get a booster (or a breakthrough infection) your immune system kicks into gear again but now it produces a broader range of antibodies. Would/could it not also be the case for exposure to the virus that doesn't result in a breakthrough infection i.e. the body detects it and fights it off successfully? (I daresay you didn't mean to imply that, just checking.)
Earlier quoted context omitted.
Yep. if you need to fight against a raging pandemic, then quickly as possible (as quickly as is tested to be safe, quickly as makes a significant difference) is the over-riding concern.
That implies we thought about it in the US, but we didn't really, and our public health people seem to be completely inflexible about everything. The schedule we used for vaccines is just what was done for their trials.
There is a reason for that - what's being deployed is what has been tested. You could work out an optimal schedule, but that might take years of trials, and meanwhile people are dying.