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The vaccine creates T-cell immunity not just antibodies. Also, the human immune system is adaptive. When it already has preexisting immunity to another variant

The vaccine creates T-cell immunity not just antibodies. Also, the human immune system is adaptive. When it already has preexisting immunity to another variant, it can adapt that immunity after a “learning” process, just like how it fights a virus that is mutating inside the host under selective pressure.

Flankk 5y ago
There is no measurement for T cell immunity though. So you're pointing to something that can't be quantified and that's not scientific. The vaccine trials were deemed a success due to high levels of neutralizing antibodies. This seems to prove that was a mistake.
- peteradio 5y ago
  There must be some mechanism to adapt a measurement to t-cells, no? How can we be sure they do anything if we don't understand their quantitative impacts. I'm aware of apparent Covid T-Cell detection kits which would tell you if you have any but you are right they are not correlated with patient outcome. I'm not aware that nABs serology is correlated with patient outcome either so why not include the existence above some threshold after some coarse verification? Incidental observation should be able to find a reasonable threshold?
- javagram 5y ago
  There is actually. And the vaccine phase 3 trial was based on empirical results reducing infection vs placebo in human bodies. NOT just based on neutralizing antibodies. https://www.jnj.com/johnson-johnson-single-shot-covid-19-vaccine-demonstrated-a-durable-immune-response-and-elicited-dual-mechanisms-of-protection-against-delta-and-other-sars-cov-2-variants-of-concern-in-data-published-in-new-england-journal-of-medicine https://www.jnj.com/johnson-johnson-single-shot-covid-19-vac... > Data showed that T-cell responses – including the important CD8+ T-cells that seek out and destroy infected cells – persisted over the eight-month timeframe examined. The Company announced topline preprint study results from this Phase 1/2a sub-study on July 1, 2021.
  - Flankk 5y ago
    T-cell proliferation is usually assessed by measuring incorporation of a radioactive tracer ([3H]thymidine), which gives the total amount of DNA synthesized in a bulk culture but provides no information on the actual frequency of specific T cells. A fluorescent dye such as bromodeoxyuridine, which intercalates into replicating chromosomes, has been widely used but is not very sensitive because of the basal T-cell proliferation. In addition, it is not possible to purify the specific live cells for further characterization. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC95974/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC95974/ The study you linked also showed vastly increased neutralizing antibodies, which is in conflict with what was posted here. You said that was fine because of T-cell proliferation, but that doesn't explain why the clinical trials produced a different result.
    - javagram 5y ago
      You do realize your link is from 2000? Science may have advanced a bit in two decades :-) https://www.nejm.org/doi/full/10.1056/NEJMc2108829 https://www.nejm.org/doi/full/10.1056/NEJMc2108829 > Spike-specific interferon-γ CD8+ and CD4+ T-cell responses were evaluated by intracellular cytokine staining assays and also showed durability and stability over this time period (Figure 1A, lower panels). The median CD8+ T-cell response was 0.0545% on day 57, 0.0554% on day 85, and 0.0734% on day 239; the median CD4+ T-cell responses were 0.0435%, 0.0322%, and 0.0176%, respectively. I think the goalposts are being moved here. Can we agree the original statement “There is no measurement for T cell immunity though. So you're pointing to something that can't be quantified and that's not scientific.” was incorrect? Furthermore , “ The study you linked also showed vastly increased neutralizing antibodies, which is in conflict with what was posted here.” Sorry, but your argument would need to be expanded a bit. Either way, can we also agree your original statement about the “ The vaccine trials were deemed a success due to high levels of neutralizing antibodies” was factually incorrect? You can review the data submitted to the FDA for EUA for both moderna and pfizer and see it was not just about antibodies, but about success in a phase 3 placebo controlled trial against the symptomatic disease in the wild.

Flankk 5y ago

There is no measurement for T cell immunity though. So you're pointing to something that can't be quantified and that's not scientific. The vaccine trials were deemed a success due to high levels of neutralizing antibodies. This seems to prove that was a mistake.

peteradio 5y ago
There must be some mechanism to adapt a measurement to t-cells, no? How can we be sure they do anything if we don't understand their quantitative impacts. I'm aware of apparent Covid T-Cell detection kits which would tell you if you have any but you are right they are not correlated with patient outcome. I'm not aware that nABs serology is correlated with patient outcome either so why not include the existence above some threshold after some coarse verification? Incidental observation should be able to find a reasonable threshold?
javagram 5y ago
There is actually. And the vaccine phase 3 trial was based on empirical results reducing infection vs placebo in human bodies. NOT just based on neutralizing antibodies. https://www.jnj.com/johnson-johnson-single-shot-covid-19-vaccine-demonstrated-a-durable-immune-response-and-elicited-dual-mechanisms-of-protection-against-delta-and-other-sars-cov-2-variants-of-concern-in-data-published-in-new-england-journal-of-medicine https://www.jnj.com/johnson-johnson-single-shot-covid-19-vac... > Data showed that T-cell responses – including the important CD8+ T-cells that seek out and destroy infected cells – persisted over the eight-month timeframe examined. The Company announced topline preprint study results from this Phase 1/2a sub-study on July 1, 2021.
- Flankk 5y ago
  T-cell proliferation is usually assessed by measuring incorporation of a radioactive tracer ([3H]thymidine), which gives the total amount of DNA synthesized in a bulk culture but provides no information on the actual frequency of specific T cells. A fluorescent dye such as bromodeoxyuridine, which intercalates into replicating chromosomes, has been widely used but is not very sensitive because of the basal T-cell proliferation. In addition, it is not possible to purify the specific live cells for further characterization. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC95974/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC95974/ The study you linked also showed vastly increased neutralizing antibodies, which is in conflict with what was posted here. You said that was fine because of T-cell proliferation, but that doesn't explain why the clinical trials produced a different result.
  - javagram 5y ago
    You do realize your link is from 2000? Science may have advanced a bit in two decades :-) https://www.nejm.org/doi/full/10.1056/NEJMc2108829 https://www.nejm.org/doi/full/10.1056/NEJMc2108829 > Spike-specific interferon-γ CD8+ and CD4+ T-cell responses were evaluated by intracellular cytokine staining assays and also showed durability and stability over this time period (Figure 1A, lower panels). The median CD8+ T-cell response was 0.0545% on day 57, 0.0554% on day 85, and 0.0734% on day 239; the median CD4+ T-cell responses were 0.0435%, 0.0322%, and 0.0176%, respectively. I think the goalposts are being moved here. Can we agree the original statement “There is no measurement for T cell immunity though. So you're pointing to something that can't be quantified and that's not scientific.” was incorrect? Furthermore , “ The study you linked also showed vastly increased neutralizing antibodies, which is in conflict with what was posted here.” Sorry, but your argument would need to be expanded a bit. Either way, can we also agree your original statement about the “ The vaccine trials were deemed a success due to high levels of neutralizing antibodies” was factually incorrect? You can review the data submitted to the FDA for EUA for both moderna and pfizer and see it was not just about antibodies, but about success in a phase 3 placebo controlled trial against the symptomatic disease in the wild.