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The mRNA encoding for the spike protein in the BioNTech vaccine is different enough from B.1.1.529 where your body doesn't recognize the spike protein on sight

The mRNA encoding for the spike protein in the BioNTech vaccine is different enough from B.1.1.529 where your body doesn't recognize the spike protein on sight but is the same enough where after you're infected the body can muster a far quicker and more complete reaction to the infection. Edit to add: the fact that vaccine + previous natural infection has a better immune response over just the vaccine likely has to do with the rest of the virus being more similar to older variants of the virus and your body recognizing some other part of the virus versus the spike itself.

mlyle 5y ago
> Edit to add: the fact that vaccine + previous natural infection has a better immune response over just the vaccine likely has to do with the rest of the virus being more similar to older variants of the virus and your body recognizing some other part of the virus versus the spike itself. This may be a factor. But, repeated exposure means more breadth of antibodies. B cells aggressively replicate and mutate in response to pathogens, and those that match are selected for. Repeating this process gets more B cells, but also broader varieties of resultant antibodies matching not just the original pathogen but things that are close to it. This is why: * 1 dose of mRNA was pretty effective against B.1.1.7, but not very effective against Delta, which had some immune escape mutations. * 2 doses of mRNA vaccines targeted at B.1.1.7 were pretty effective against Delta, but only slightly effective against Omicron, which had a lot of (different) immune escape mutations. * 3 doses of mRNA vaccines targeted at B.1.1.7 seem pretty effective against Omicron.
- selectodude 5y ago
  As I understand it, the boosters do a much better job "training" (for lack of a better term) B cells. That being said, I'm going off the preliminary study that shows that vaccine >= infection for older variants whereas vaccine + infection >> vaccine for omicron. As an aside, I've got three shots of Moderna in me and I caught omicron during the covidtastrophe a few weeks ago. It was extremely mild but I'm now resigned to the idea that vaccines are an assurance against getting actually sick more than a silver bullet.
  - mlyle 5y ago
    > That being said, I'm going off the preliminary study that shows that vaccine >= infection for older variants whereas vaccine + infection >> vaccine for omicron. More exposure basically means broader protection-- whether it's exposure through infection, vaccination, etc. Whatever you're exposed to, the compliment and quantity of antibodies widens and is drawn towards whatever you're exposed to. You end up with antibodies that bind against whatever you're exposed to in many different ways-- many of which will be cross-reactive against other variants. Obviously, it'd be nice if we had a omicron-based booster, because it would be broadening the protection more in that direction. > As an aside, I've got three shots of Moderna in me and I caught omicron during the covidtastrophe a few weeks ago. Sorry to hear that. We still have relatively little data, but it looks our best current guesses are: * Vs. Delta: 2 doses of Pfizer/Moderna: about 60-70% effective against infection, 80-90% effective against symptoms, and 95%+ effective against severe illness. * Vs. Omicron: 2 doses of Pfizer/Moderna: ???% (poor) effective against infection, 30% effective against symptoms, 50-70% effective against severe illness. 3 doses of Pfizer/Moderna: ???% (maybe moderate) efficacy against infection, 60%??? effective against symptoms (evidence quality poor), 85% effective against severe illness. It also looks like this is short lived and sloping down relatively fast. In any case, you're protected every step of the way: Less likely to become infected, less likely to become symptomatic if infected, and less likely to develop severe illness if symptomatic. One interesting epidemiological question is: vaccinated people are pretty likely to be asymptomatic with Omicron, so they may be more likely to spread it.
- chana_masala 5y ago
  And 4 doses for the coming Sigma variant? It seems never ending with these leaky vaccines
  - mlyle 5y ago
    > And 4 doses for the coming Sigma variant? It seems never ending with these leaky vaccines On the other hand, these "leaky vaccines" have already prevented a massive amount of mortality. Yes, the duration and quality of protection, even boosted, against Omicron is unfortunate... but even 2 doses can still be expected to save a high number of lives from Omicron.
    - chana_masala 5y ago
      I doubt that in the long term. The long term health effects of the vaccine are largely unknown but already looking grim.
      - jbd28 5y ago
        chana_masala 5y ago
        dang 5y ago
        Could you please stop posting flamewar comments to HN? You've been doing it a lot, unfortunately, and we ban that sort of account. It's not what this site is for, and it destroys what it is for. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
        chana_masala 5y ago
        OK, thank you

mlyle 5y ago

> Edit to add: the fact that vaccine + previous natural infection has a better immune response over just the vaccine likely has to do with the rest of the virus being more similar to older variants of the virus and your body recognizing some other part of the virus versus the spike itself. This may be a factor. But, repeated exposure means more breadth of antibodies. B cells aggressively replicate and mutate in response to pathogens, and those that match are selected for. Repeating this process gets more B cells, but also broader varieties of resultant antibodies matching not just the original pathogen but things that are close to it. This is why: * 1 dose of mRNA was pretty effective against B.1.1.7, but not very effective against Delta, which had some immune escape mutations. * 2 doses of mRNA vaccines targeted at B.1.1.7 were pretty effective against Delta, but only slightly effective against Omicron, which had a lot of (different) immune escape mutations. * 3 doses of mRNA vaccines targeted at B.1.1.7 seem pretty effective against Omicron.

selectodude 5y ago
As I understand it, the boosters do a much better job "training" (for lack of a better term) B cells. That being said, I'm going off the preliminary study that shows that vaccine >= infection for older variants whereas vaccine + infection >> vaccine for omicron. As an aside, I've got three shots of Moderna in me and I caught omicron during the covidtastrophe a few weeks ago. It was extremely mild but I'm now resigned to the idea that vaccines are an assurance against getting actually sick more than a silver bullet.
- mlyle 5y ago
  > That being said, I'm going off the preliminary study that shows that vaccine >= infection for older variants whereas vaccine + infection >> vaccine for omicron. More exposure basically means broader protection-- whether it's exposure through infection, vaccination, etc. Whatever you're exposed to, the compliment and quantity of antibodies widens and is drawn towards whatever you're exposed to. You end up with antibodies that bind against whatever you're exposed to in many different ways-- many of which will be cross-reactive against other variants. Obviously, it'd be nice if we had a omicron-based booster, because it would be broadening the protection more in that direction. > As an aside, I've got three shots of Moderna in me and I caught omicron during the covidtastrophe a few weeks ago. Sorry to hear that. We still have relatively little data, but it looks our best current guesses are: * Vs. Delta: 2 doses of Pfizer/Moderna: about 60-70% effective against infection, 80-90% effective against symptoms, and 95%+ effective against severe illness. * Vs. Omicron: 2 doses of Pfizer/Moderna: ???% (poor) effective against infection, 30% effective against symptoms, 50-70% effective against severe illness. 3 doses of Pfizer/Moderna: ???% (maybe moderate) efficacy against infection, 60%??? effective against symptoms (evidence quality poor), 85% effective against severe illness. It also looks like this is short lived and sloping down relatively fast. In any case, you're protected every step of the way: Less likely to become infected, less likely to become symptomatic if infected, and less likely to develop severe illness if symptomatic. One interesting epidemiological question is: vaccinated people are pretty likely to be asymptomatic with Omicron, so they may be more likely to spread it.
chana_masala 5y ago
And 4 doses for the coming Sigma variant? It seems never ending with these leaky vaccines
- mlyle 5y ago
  > And 4 doses for the coming Sigma variant? It seems never ending with these leaky vaccines On the other hand, these "leaky vaccines" have already prevented a massive amount of mortality. Yes, the duration and quality of protection, even boosted, against Omicron is unfortunate... but even 2 doses can still be expected to save a high number of lives from Omicron.
  - chana_masala 5y ago
    I doubt that in the long term. The long term health effects of the vaccine are largely unknown but already looking grim.
    - jbd28 5y ago
      - chana_masala 5y ago
        dang 5y ago
        Could you please stop posting flamewar comments to HN? You've been doing it a lot, unfortunately, and we ban that sort of account. It's not what this site is for, and it destroys what it is for. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
        chana_masala 5y ago
        OK, thank you