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> all 3 of them told me to expect something like that - the virus mutates ... and the vaccines will likely be needing to adjust Your doctor friends were inform
by criticaltinker 5y ago
> all 3 of them told me to expect something like that - the virus mutates ... and the vaccines will likely be needing to adjust
Your doctor friends were informing you about a phenomenon commonly referred to as "immune escape".
The current mRNA based SARS-CoV-2 vaccines are effective at preventing severe outcomes like hospitalization and death. However, they do not necessarily prevent infection or transmission - and they induce an immune response highly targeted toward the spike protein RBD [1]. Combined with mass vaccination strategies, these factors contribute to a situation that exerts tremendous selective pressure on the virus, and can result in convergent mutations that are advantageous for the virus in a large population of people [1][2]. These mutations can lead to partial or complete immune escape, which manifests as increased transmission or virulence, reduced vaccine efficacy, and reduced immunity in naturally infected individuals.
> Even the highest levels of vaccination are no protection
It's not quite accurate to say "are no protection". I would rephrase as:
Strategies for viral elimination should therefore be diversified across molecular targets and therapeutic modalities [1]
[1] Risk of rapid evolutionary escape from biomedical interventions targeting SARS-CoV-2 spike protein
https://pubmed.ncbi.nlm.nih.gov/33909660/ https://pubmed.ncbi.nlm.nih.gov/33909660/
[2] SARS-CoV-2 immune evasion by the B.1.427/B.1.429 variant of concern
https://science.sciencemag.org/content/early/2021/06/30/science.abi7994 https://science.sciencemag.org/content/early/2021/06/30/scie...
- maxerickson 5y agoThe Delta variant emerged prior to widespread vaccination.
- criticaltinker 5y agoYes the delta variant may have originated prior to widespread vaccination, but the dominance of the delta variant (and other VOCs) did coincide with mass vaccination campaigns. Please see the first source I cited if you're interested in these ideas and want to hear more straight from the experts: > "The spike protein receptor-binding domain (RBD) of SARS-CoV-2 is the molecular target for many vaccines and antibody-based prophylactics aimed at bringing COVID-19 under control." [1] > "Such a narrow molecular focus raises the specter of viral immune evasion as a potential failure mode for these biomedical interventions. With the emergence of new strains of SARS-CoV-2 with altered transmissibility and immune evasion potential, a critical question is this: how easily can the virus escape neutralizing antibodies (nAbs) targeting the spike RBD?" [1] > "Our modeling suggests that SARS-CoV-2 mutants with one or two mildly deleterious mutations are expected to exist in high numbers due to neutral genetic variation, and consequently resistance to vaccines or other prophylactics that rely on one or two antibodies for protection can develop quickly -and repeatedly- under positive selection." [1] > "The speed at which nAb resistance develops in the population increases substantially as the number of infected individuals increases, suggesting that complementary strategies to prevent SARS-CoV-2 transmission that exert specific pressure on other proteins (e.g., antiviral prophylactics) or that do not exert a specific selective pressure on the virus (e.g., high-efficiency air filtration, masking, ultraviolet air purification) are key to reducing the risk of immune escape" [1] > "Strategies for viral elimination should therefore be diversified across molecular targets and therapeutic modalities" [1]
- maxerickson 5y agoIt would have spread even faster without vaccination (it is considerably more infectious than other prevalent variants).
- criticaltinker 5y agoTo be clear, the primary suggestion put forth by my original comment is: Strategies for viral elimination should therefore be diversified across molecular targets and therapeutic modalities Put another way: vaccines are a powerful and useful tool that can help us mitigate the pandemic, but if used indiscriminately they may actually work against us, so we need to proceed with caution and also use other tools where possible.
- maxerickson 5y agoI don't know how you'd adjudicate it, but I'd bet quite a lot that indiscriminate use of a (tested, safe) vaccine is pretty much always going to be better than not using it. There's of course no reason to stop at indiscriminate use of it, we should employ whatever vaccine strategy seems to be best (in an empirical sense), and supplement with other measures, I'm going at the banality of the point.
- rsfern 5y agoI agree with the general point that diversifying our vaccine targets is important for robust immunity, but you are sort of coming close to advocating that we not use the particular somewhat limited vaccine tech we have at our disposal now. The best strategy against escape variants available to us right now is to reduce transmission rates (especially to immunocompromised people) as much as possible with high vaccination rates. https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(21)00202-4/fulltext https://www.thelancet.com/journals/laninf/article/PIIS1473-3...
- criticaltinker 5y agoThe core point of the OP article - and the data coming out of Israel - is that mass vaccination alone is less effective than expected at preventing the surge of transmission and infection by variants of concern. The article you cited is in agreement with the literature I previously cited - as more people are infected the virus has more opportunity to mutate. > The best strategy against escape variants available to us right now is to reduce transmission rates ... as much as possible with high vaccination rates Your comment contradicts the mounting evidence we have available to us. Yes we need to use the vaccine tech we have at our disposal now - but in a highly targeted way, and supplemented by other viral elimination strategies that do not exert specific selective pressure on the virus.
- dillondoyle 5y agoSo if I'm understanding you: I am planning on taking my Governor's cheekily endorsed thumbs up to get a 3rd shot. I'm going to get JJ because it's not the same RNA spike target. That's probably better than a 3rd RNA shot (no reformulated)?
- criticaltinker 5y ago> That's probably better than a 3rd RNA shot To be clear, right now there's no scientific literature that conclusively supports your suggestion here. A better takeaway from my comment and OP would be that there is evidence we must diversify our viral elimination strategies at a population level. It might actually be best to for you personally to stick with the same vaccines you had previously, but I'm going to stop there because you should consult your doctor for decisions like that.
- tguvot 5y agomoderna and pfizer are different. different enough for moderna to be more efficient with delta and pfizer more efficient with alfa
- dillondoyle 5y agothanks!
- ianai 5y agoWhat keeps me worried is how much community immunity is required to stop a virus as spreadable as measles. I think it’s something like 95%. That’s a hard bar to pass for a vaccine or even “natural immunity” through letting it spread. Mixed with the possibility of long covid we could see some scary disease rates for the foreseeable future.
- LifeIsThermal 5y agoNatural immunity gives "ultrapotent" antibodies that works for 23 variants, including delta. That´s what will end this pandemic. Everyone will get infected, vaccinated and unvaccinated. Ultrapotent antibodies against diverse and highly transmissible SARS-CoV-2 variants ”Wang et al. identified four antibodies from early-outbreak convalescent donors that are potent against 23 variants, including variants of concern” ”The B cells isolated from donor-derived blood samples were sorted for antibody identification. This led to the identification of four potent neutralizing antibodies targeting the spike RBD. These antibodies showed a high affinity for the SARS-CoV-2 spike even at nanomolar concentrations.” ”The findings revealed that of 4 antibodies, two bound to RBDs in the “up position” and two bound to RBDs in the “down position.” Moreover, three out of four antibodies directly blocked the RBD – ACE2 interaction, and one indirectly inhibited the interaction through steric hindrance - the slowing of chemical reactions due to steric bulk.” ”By conducting multiple rounds of selection using combination treatments with two antibodies, it was observed that antibody combinations might reduce the risk of escape mutation acquisition and subsequent development of resistant viral variants.” https://science.sciencemag.org/content/early/2021/06/30/science.abh1766 https://science.sciencemag.org/content/early/2021/06/30/scie...
- Barrin92 5y ago>The current mRNA based SARS-CoV-2 vaccines are effective at preventing severe outcomes like hospitalization and death According to this very article this isn't even really true any more. Of the currently hospitalized population in Israel 60% are fully vaccinated. With 78% of the population vaccinated that implies the protection is actually surprisingly weak. " “There are so many breakthrough infections that they dominate and most of the hospitalized patients are actually vaccinated,” says Uri Shalit, a bioinformatician at the Israel Institute of Technology (Technion) who has consulted on COVID-19 for the government. “One of the big stories from Israel [is]: ‘Vaccines work, but not well enough.’”
- danmaz74 5y agoWhat is the age of the hospitalised, and what is the vaccination rate for that age range? I expect most of the hospitalised to be elderly, and most of the non vaccinated to be young.
- _kbh_ 5y agoWouldn't you have to look at the age of the population that is in hospital and that populations vaccination rate to accurately gauge this?. The overall vaccination rate could be vastly lower or higher than the overall population depending on what priority groups israel had.
- mping 5y agoIf vaccines bring hospitalizations down they are already a win. The percentage doesn't say much about the number of hospitalizations. In a country where lots of people are vaccinated, I would expect lots of vaccinated people in the hospital too. Like others said, it also depends on the cohort (age, vulnerability, etc.).
- convnet 5y agoThat's a misinterpretation of the statistics. The most vulnerable population has a much higher vaccination rate than the population as a whole, with well over 90% of Israelis over 70 vaccinated. People over 70 have a much higher chance of being hospitalized, so to only see 60% of hospitalizations be of vaccinated people shows how effective the vaccine still is at preventing serious disease.