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I can't believe you are getting downvoted! This is a real risk! Relevant quote: > Under normal conditions, highly virulent strains of the virus are not selec

by 1996 6y ago

I can't believe you are getting downvoted! This is a real risk! Relevant quote: > Under normal conditions, highly virulent strains of the virus are not selected. A highly virulent strain would kill the host before the virus would have an opportunity to transmit to other potential hosts and replicate. Thus, less virulent strains are selected. These strains are virulent enough to induce symptoms but not enough to kill the host, allowing further transmission. However, the leaky vaccine changes this evolutionary pressure and permits the evolution of highly virulent strains.[12] The vaccine's inability to prevent infection and transmission allows the spread of highly virulent strains among vaccinated chickens. The fitness of the more virulent strains are increased by the vaccine. (...) > Highly virulent strains have been selected to the point that any chicken that is unvaccinated will die if infected. Other leaky vaccines are commonly used in agriculture. One vaccine in particular is the vaccine for avian influenza. Leaky vaccine use for avian influenza can select for virulent strains which could potentially be transmitted to humans.[13]

alkonaut 6y ago
> This is a real risk! I never heard this discussed as a big "risk". As far as I know this was always more or less known to be the endgame and not even a dangerous outcome but the "good" scenario. Once it's an established coronavirus, it can be like the other known human coronaviruses we already have. The reason you don't die from OC43 at age 75 now is because you probably cought it a few times before that. It's not necessarily because OC43 doesn't have a high IFR at high ages. We don't know that because we don't have a large sample of it. For all we know, one or more of the existing HCOVs may have been quite a deadly disease back when it entered the population. We aren't going to exterminate SARS-COV2. Especially obvious since it's not limited to humans (present in mink, cats, primates, ...). And that's not going to be a big problem.
- doktorhladnjak 6y ago
  There’s a theory published in some academic research in virology about OC43 possibly being what caused the 1889-1890 “flu” pandemic
- 2-tpg 6y ago
  > I never heard this discussed as a big "risk". As far as I know this was always more or less known to be the endgame and not even a dangerous outcome but the "good" scenario. The endgame is for the virus to turn into a community virus. This is not the big "risk". The big risk is in using leaky vaccines to combat the mortality and morbidity until we get there (or can reset economy). In chickens, use of leaky vaccines lead to the evolution of a disease which kills nearly all non-vaccinated. That's nothing like the seasonal flu (which would be a "good" outcome, indeed). You'll find expert back-and-forth on leaky vaccines risk for humans here: https://science.sciencemag.org/content/349/6247/461 https://science.sciencemag.org/content/349/6247/461 "Risk of ‘leaky’ vaccines debated" (2015) > Vaccines have saved millions of human lives, but according to evolutionary biologist Andrew Read they sometimes may also cause pathogens to turn deadlier. Read first put forward the theory 15 years ago. Now, in a new paper, he presents evidence that that is what happened with the virus causing Marek's disease, an infectious disease in chickens. Read acknowledges that the effect has never been seen with human vaccines, but he argues that future vaccines that prevent disease rather than infection could have the same effect. Other researchers say that no general conclusions should be drawn from the paper. Even if he turns out to be right, the study offers no support whatsoever for those who oppose vaccination, Read stresses. If "leaky" vaccines are proven safe and effective, they should be used, he says, but perhaps with closer monitoring and additional measures to reduce transmission, such as bed nets for malaria. And for all the solid risk management in the West, China, a country where: - SARS-1 leaked twice from a lab, - which re-sentences Australian citizens to a death penalty as diplomatic punishment for Australia wanting joint investigation into the origin of a disease with still unknown zoonotic basis - which would not allow WHO full access, and put information blackout its scientists - informed the world way too late of an upcoming pandemic, pressuring the WHO to geopolitics and trade instead of world health. That country will vaccinate a billion people with a leaky vaccine that skipped a trial with a poorly estimated 50.5% efficiency. Risky as all-living hell.
deleted 6y ago
[deleted]
JohnHaugeland 6y ago
> Under normal conditions, highly virulent strains of the virus are not selected. A highly virulent strain would kill the host before the virus would have an opportunity to transmit to other potential hosts and replicate. Thus, less virulent strains are selected. This is not correct. What is selected against is deadliness, which is not correctly referred to as "virulence." By example, the virulence of the kind of herpes that most Americans call "cold sores" is off the charts: you can get it from a single kiss. But because the host barely notices, it's not a big deal. Similarly, a great number of diseases occur to AIDS patients because they're omnipresent, but cause no harm in normal conditions. Don't even get me started on mononucleosis. And then, of course, this is just a generalization; measles and many kinds of meningitis are ridiculously virulent, as well as extremely deadly.
- erik_seaberg 6y ago
  https://en.wikipedia.org/wiki/Virulence https://en.wikipedia.org/wiki/Virulence is how harmful it is, https://en.wikipedia.org/wiki/Infection#Contagiousness https://en.wikipedia.org/wiki/Infection#Contagiousness is how readily it spreads. They’re related because a lot of the harm a disease does is a side effect of using your body to become more contagious (e.g., coughing due to chest congestion).

by 1996 6y ago

alkonaut 6y ago

> This is a real risk! I never heard this discussed as a big "risk". As far as I know this was always more or less known to be the endgame and not even a dangerous outcome but the "good" scenario. Once it's an established coronavirus, it can be like the other known human coronaviruses we already have. The reason you don't die from OC43 at age 75 now is because you probably cought it a few times before that. It's not necessarily because OC43 doesn't have a high IFR at high ages. We don't know that because we don't have a large sample of it. For all we know, one or more of the existing HCOVs may have been quite a deadly disease back when it entered the population. We aren't going to exterminate SARS-COV2. Especially obvious since it's not limited to humans (present in mink, cats, primates, ...). And that's not going to be a big problem.

doktorhladnjak 6y ago
There’s a theory published in some academic research in virology about OC43 possibly being what caused the 1889-1890 “flu” pandemic
2-tpg 6y ago
> I never heard this discussed as a big "risk". As far as I know this was always more or less known to be the endgame and not even a dangerous outcome but the "good" scenario. The endgame is for the virus to turn into a community virus. This is not the big "risk". The big risk is in using leaky vaccines to combat the mortality and morbidity until we get there (or can reset economy). In chickens, use of leaky vaccines lead to the evolution of a disease which kills nearly all non-vaccinated. That's nothing like the seasonal flu (which would be a "good" outcome, indeed). You'll find expert back-and-forth on leaky vaccines risk for humans here: https://science.sciencemag.org/content/349/6247/461 https://science.sciencemag.org/content/349/6247/461 "Risk of ‘leaky’ vaccines debated" (2015) > Vaccines have saved millions of human lives, but according to evolutionary biologist Andrew Read they sometimes may also cause pathogens to turn deadlier. Read first put forward the theory 15 years ago. Now, in a new paper, he presents evidence that that is what happened with the virus causing Marek's disease, an infectious disease in chickens. Read acknowledges that the effect has never been seen with human vaccines, but he argues that future vaccines that prevent disease rather than infection could have the same effect. Other researchers say that no general conclusions should be drawn from the paper. Even if he turns out to be right, the study offers no support whatsoever for those who oppose vaccination, Read stresses. If "leaky" vaccines are proven safe and effective, they should be used, he says, but perhaps with closer monitoring and additional measures to reduce transmission, such as bed nets for malaria. And for all the solid risk management in the West, China, a country where: - SARS-1 leaked twice from a lab, - which re-sentences Australian citizens to a death penalty as diplomatic punishment for Australia wanting joint investigation into the origin of a disease with still unknown zoonotic basis - which would not allow WHO full access, and put information blackout its scientists - informed the world way too late of an upcoming pandemic, pressuring the WHO to geopolitics and trade instead of world health. That country will vaccinate a billion people with a leaky vaccine that skipped a trial with a poorly estimated 50.5% efficiency. Risky as all-living hell.

deleted 6y ago

[deleted]

JohnHaugeland 6y ago

> Under normal conditions, highly virulent strains of the virus are not selected. A highly virulent strain would kill the host before the virus would have an opportunity to transmit to other potential hosts and replicate. Thus, less virulent strains are selected. This is not correct. What is selected against is deadliness, which is not correctly referred to as "virulence." By example, the virulence of the kind of herpes that most Americans call "cold sores" is off the charts: you can get it from a single kiss. But because the host barely notices, it's not a big deal. Similarly, a great number of diseases occur to AIDS patients because they're omnipresent, but cause no harm in normal conditions. Don't even get me started on mononucleosis. And then, of course, this is just a generalization; measles and many kinds of meningitis are ridiculously virulent, as well as extremely deadly.

erik_seaberg 6y ago
https://en.wikipedia.org/wiki/Virulence https://en.wikipedia.org/wiki/Virulence is how harmful it is, https://en.wikipedia.org/wiki/Infection#Contagiousness https://en.wikipedia.org/wiki/Infection#Contagiousness is how readily it spreads. They’re related because a lot of the harm a disease does is a side effect of using your body to become more contagious (e.g., coughing due to chest congestion).