4 ms·

>Vaccines that let the hosts survive but do not prevent the spread of the pathogen relax this selection, allowing the evolution of hotter pathogens to occur. Th

>Vaccines that let the hosts survive but do not prevent the spread of the pathogen relax this selection, allowing the evolution of hotter pathogens to occur. This type of vaccine is often called a leaky vaccine. When vaccines prevent transmission, as is the case for nearly all vaccines used in humans, this type of evolution towards increased virulence is blocked. But when vaccines leak, allowing at least some pathogen transmission, they could create the ecological conditions that would allow hot strains to emerge and persist. Very relevant when coupled with the Massachusetts study that showed that the vaccinated can still spread Delta with apparently very little problem. https://www.cdc.gov/mmwr/volumes/70/wr/mm7031e2.htm?s_cid=mm7031e2_w https://www.cdc.gov/mmwr/volumes/70/wr/mm7031e2.htm?s_cid=mm...

0x_rs 5y ago
I certainly hope the similarities with Marek's disease reaching 100% mortality begin and end there. What I can personally extrapolate is that allowing or even advising vaccinated people not to wear masks and distancing is rather dangerous. https://en.wikipedia.org/wiki/Marek%27s_disease#Diagnosis https://en.wikipedia.org/wiki/Marek%27s_disease#Diagnosis
- __blockcipher__ 5y ago
  Masking has never been sufficiently proven to be effective against the spread of respiratory viruses. For SARS-2 specifically we have one randomized controlled trial, DANMASK, which showed no effect of masking (note the primary endpoint was self-infection not community transmission, but self-infection is a decent proxy, and furthermore community transmission is incredibly difficult to study, which is why it is so evil to me that the public health establishment convinced people that "my mask protects you, but not me" when there's actually never been evidence that it protects others as evidenced by the utter lack of studies on that part specifically) For the pre-2020 studies, they were more or less in agreement that masks didn't help, even in healthcare workers, who tend to be better trained and more compliant with masking protocols. Indeed Macintyre et al provides strong evidence of the risks of cloth mask wearing; while this study compared cloth masking to standard practice, not no-masking, it at a minimum establishes the very real risks of cloth mask wearing: https://pubmed.ncbi.nlm.nih.gov/25903751/ https://pubmed.ncbi.nlm.nih.gov/25903751/
  - lucas_codes 5y ago
    "There is no evidence" means only that, it doesn't mean we shouldn't wear masks to prevent community transmission. You can still use logic. It's a virus where transmission is heavily influenced by water droplets. Masks limit the reach of water droplets from the nose and mouth. Also it is unlikely for there to be a large study for ethical reasons (if wearing a mask might help, you can't get a control group). > it at a minimum establishes the very real risks of cloth mask wearing That is a pretty gross misreading of a study which has no non-mask control group and looked very different conditions to the pandemic
scythe 5y ago
It appears that vaccinated people don't remain contagious as long, though: https://www.medrxiv.org/content/10.1101/2021.07.28.21261295v1.full.pdf#page=16 https://www.medrxiv.org/content/10.1101/2021.07.28.21261295v...
loopz 5y ago
A possibility [1] [2], though contagion is shortened substantially with vaccine, so unlikely still. Probably a good idea to wear masks and physical distance until infections go down. This virus being novel and widespread, there's nothing to do to stop random mutations. But avoid training it, and get the shots. [1] https://www.businessinsider.com/covid-transmission-vaccinated-people-risk-of-resistant-variant-2021-7?op=1&r=US&IR=T https://www.businessinsider.com/covid-transmission-vaccinate... [2] https://pubmed.ncbi.nlm.nih.gov/34268529/ https://pubmed.ncbi.nlm.nih.gov/34268529/
thisiscorrect 5y ago
It's not just Massachusetts finding that the vaccine doesn't prevent infection. Iceland[2], France, Britain, Germany[2], Australia[3], and Israel[4] are seeing diminished effectiveness of vaccination. The Israeli study in particular is interesting because it divided the vaccinees into two groups of equal size, partitioning by median time since vaccination (146 days), and found that the cohort vaccinated earlier see less protection than those vaccinated more recently. That seems to suggest it's not necessarily the delta variant that's making the difference but time since vaccination. [1] https://www.icelandreview.com/society/covid-19-in-iceland-vaccination-has-not-led-to-herd-immunity-says-chief-epidemiologist/ https://www.icelandreview.com/society/covid-19-in-iceland-va... [2] https://www.seattletimes.com/nation-world/germany-france-and-britain-prepare-for-coronavirus-vaccine-boosters-starting-in-september/ https://www.seattletimes.com/nation-world/germany-france-and... [3] https://youtu.be/46vq4Mn2DUQ?t=270 https://youtu.be/46vq4Mn2DUQ?t=270 [4] https://www.medrxiv.org/content/10.1101/2021.08.03.21261496v1 https://www.medrxiv.org/content/10.1101/2021.08.03.21261496v...
noduerme 5y ago
Looking at Provincetown, it's far from obvious that this is what happened. It seems more likely that a lot of vaccinated people got the virus in close proximity to unvaccinated people, but the chain of transmission mostly stopped there. Numbers in Provincetown have fallen and there were no reports of major outbreaks when vaccinated people returned home. So it would seem like you could have vaccinated-to-unvaccinated spread in some cases, but vaxed-to-vaxed is multiples less likely. With the large majority of the world still unvaccinated, and most spread (apparently) curtailed between vaccinated individuals, the evolutionary pressure on the virus will still be toward longer incubation and less lethality. Perhaps if we ever reach a point of worldwide herd immunity by vaccination, and still have large scale circulation of the virus among the vaccinated, we'd be looking at a different evolutionary drift. But it's also worth noting that the relevant mutations in Covid-19 are on the spike protein, and there aren't so many configurations, only a few hundred; it's likely that all possible configurations have already been "tried", and are currently competing in the wild.
- __blockcipher__ 5y ago
  > Numbers in Provincetown have fallen and there were no reports of major outbreaks when vaccinated people returned home. So it would seem like you could have vaccinated-to-unvaccinated spread in some cases, but vaxed-to-vaxed is multiples less likely. I think time will show this to be false. A shockingly high number of the vaccinated have actually already had COVID (some of them explicitly knew they had it yet chose to get vaccinated anyway, sometimes at the advice of their doctors, which is horrifying to me insofar as it reveals fundamental ignorance about natural immunity), but of those who haven't been exposed to real SARS-2, a strain capable of readily infecting them will just as easily pass to their vaccinated friend, given the "strategy" of the virus is to acquire point mutations on the S2 subunit that render the vaccines (which protect ONLY against the spike protein) ineffective
  - loopz 5y ago
    Report show that vaccine may provide broader defense though: https://www.nih.gov/how-immunity-generated-covid-19-vaccines-differs-infection https://www.nih.gov/how-immunity-generated-covid-19-vaccines...

0x_rs 5y ago

I certainly hope the similarities with Marek's disease reaching 100% mortality begin and end there. What I can personally extrapolate is that allowing or even advising vaccinated people not to wear masks and distancing is rather dangerous. https://en.wikipedia.org/wiki/Marek%27s_disease#Diagnosis https://en.wikipedia.org/wiki/Marek%27s_disease#Diagnosis

__blockcipher__ 5y ago
Masking has never been sufficiently proven to be effective against the spread of respiratory viruses. For SARS-2 specifically we have one randomized controlled trial, DANMASK, which showed no effect of masking (note the primary endpoint was self-infection not community transmission, but self-infection is a decent proxy, and furthermore community transmission is incredibly difficult to study, which is why it is so evil to me that the public health establishment convinced people that "my mask protects you, but not me" when there's actually never been evidence that it protects others as evidenced by the utter lack of studies on that part specifically) For the pre-2020 studies, they were more or less in agreement that masks didn't help, even in healthcare workers, who tend to be better trained and more compliant with masking protocols. Indeed Macintyre et al provides strong evidence of the risks of cloth mask wearing; while this study compared cloth masking to standard practice, not no-masking, it at a minimum establishes the very real risks of cloth mask wearing: https://pubmed.ncbi.nlm.nih.gov/25903751/ https://pubmed.ncbi.nlm.nih.gov/25903751/
- lucas_codes 5y ago
  "There is no evidence" means only that, it doesn't mean we shouldn't wear masks to prevent community transmission. You can still use logic. It's a virus where transmission is heavily influenced by water droplets. Masks limit the reach of water droplets from the nose and mouth. Also it is unlikely for there to be a large study for ethical reasons (if wearing a mask might help, you can't get a control group). > it at a minimum establishes the very real risks of cloth mask wearing That is a pretty gross misreading of a study which has no non-mask control group and looked very different conditions to the pandemic

scythe 5y ago

It appears that vaccinated people don't remain contagious as long, though: https://www.medrxiv.org/content/10.1101/2021.07.28.21261295v1.full.pdf#page=16 https://www.medrxiv.org/content/10.1101/2021.07.28.21261295v...

loopz 5y ago

A possibility [1] [2], though contagion is shortened substantially with vaccine, so unlikely still. Probably a good idea to wear masks and physical distance until infections go down. This virus being novel and widespread, there's nothing to do to stop random mutations. But avoid training it, and get the shots. [1] https://www.businessinsider.com/covid-transmission-vaccinated-people-risk-of-resistant-variant-2021-7?op=1&r=US&IR=T https://www.businessinsider.com/covid-transmission-vaccinate... [2] https://pubmed.ncbi.nlm.nih.gov/34268529/ https://pubmed.ncbi.nlm.nih.gov/34268529/

thisiscorrect 5y ago

It's not just Massachusetts finding that the vaccine doesn't prevent infection. Iceland[2], France, Britain, Germany[2], Australia[3], and Israel[4] are seeing diminished effectiveness of vaccination. The Israeli study in particular is interesting because it divided the vaccinees into two groups of equal size, partitioning by median time since vaccination (146 days), and found that the cohort vaccinated earlier see less protection than those vaccinated more recently. That seems to suggest it's not necessarily the delta variant that's making the difference but time since vaccination. [1] https://www.icelandreview.com/society/covid-19-in-iceland-vaccination-has-not-led-to-herd-immunity-says-chief-epidemiologist/ https://www.icelandreview.com/society/covid-19-in-iceland-va... [2] https://www.seattletimes.com/nation-world/germany-france-and-britain-prepare-for-coronavirus-vaccine-boosters-starting-in-september/ https://www.seattletimes.com/nation-world/germany-france-and... [3] https://youtu.be/46vq4Mn2DUQ?t=270 https://youtu.be/46vq4Mn2DUQ?t=270 [4] https://www.medrxiv.org/content/10.1101/2021.08.03.21261496v1 https://www.medrxiv.org/content/10.1101/2021.08.03.21261496v...

noduerme 5y ago

Looking at Provincetown, it's far from obvious that this is what happened. It seems more likely that a lot of vaccinated people got the virus in close proximity to unvaccinated people, but the chain of transmission mostly stopped there. Numbers in Provincetown have fallen and there were no reports of major outbreaks when vaccinated people returned home. So it would seem like you could have vaccinated-to-unvaccinated spread in some cases, but vaxed-to-vaxed is multiples less likely. With the large majority of the world still unvaccinated, and most spread (apparently) curtailed between vaccinated individuals, the evolutionary pressure on the virus will still be toward longer incubation and less lethality. Perhaps if we ever reach a point of worldwide herd immunity by vaccination, and still have large scale circulation of the virus among the vaccinated, we'd be looking at a different evolutionary drift. But it's also worth noting that the relevant mutations in Covid-19 are on the spike protein, and there aren't so many configurations, only a few hundred; it's likely that all possible configurations have already been "tried", and are currently competing in the wild.

__blockcipher__ 5y ago
> Numbers in Provincetown have fallen and there were no reports of major outbreaks when vaccinated people returned home. So it would seem like you could have vaccinated-to-unvaccinated spread in some cases, but vaxed-to-vaxed is multiples less likely. I think time will show this to be false. A shockingly high number of the vaccinated have actually already had COVID (some of them explicitly knew they had it yet chose to get vaccinated anyway, sometimes at the advice of their doctors, which is horrifying to me insofar as it reveals fundamental ignorance about natural immunity), but of those who haven't been exposed to real SARS-2, a strain capable of readily infecting them will just as easily pass to their vaccinated friend, given the "strategy" of the virus is to acquire point mutations on the S2 subunit that render the vaccines (which protect ONLY against the spike protein) ineffective
- loopz 5y ago
  Report show that vaccine may provide broader defense though: https://www.nih.gov/how-immunity-generated-covid-19-vaccines-differs-infection https://www.nih.gov/how-immunity-generated-covid-19-vaccines...