6 ms·

No reason to be afraid of new strains. Coronaviruses become less deadly as they evolve to become better at spreading.

brianbreslin 6y ago
That's a mixed bag, as on one hand sure the number of dead goes down per 100, but then the number of folks infected goes up, thereby meaning the same number of dead possibly, or more people infected in hospitals.
- slumdev 6y ago
  SARS-CoV-2, by best estimates (0.3% mortality), is roughly 3x as deadly as the seasonal flu. The common cold is a coronavirus. It is significantly less deadly than the seasonal flu. We have every reason to believe that a more contagious but less deadly version will resemble the common cold.
  - alicorn 6y ago
    Common cold is caused by a variety of viruses, only a small subset of which is coronaviruses. Look it up.
  - thehappypm 6y ago
    The mortality rate is higher than .3%. .3% of New York City has already died. Unless the vast majority of New Yorkers have already contracted the virus, the mortality rate has to be substantially higher than .3%.
  - tsimionescu 6y ago
    SARS1 was also a coronavirus, and it had more than 50% mortality for those infected. The virus strain tells you nothing about its mortality. SARS-CoV-2 is also only ~3x as deadly as the flu WITH UNPRECEDENTED MEASURES TO CONTAIN IT. In areas where it wasn't contain, such as the initial outbreak in Italy that overwhelmed hospitals, it was 10x or more as deadly as the flu.
- paganel 6y ago
  At some point the virus will run out of people to infect.
  - sjg007 6y ago
    It actually will just continue to mutate and start reinfecting people as immunity wanes.
  - lazide 6y ago
    Influenza certainly hasn't. It will mutate past defenses, and survive, just as seasonal coronaviruses have - unless a concerted effort occurs to completely eradicate it, and that effort is successful.
wittyreference 6y ago
Viruses are believed to become less deadly over time when being less deadly offers an evolutionary advantage in ability to spread. If being more deadly and more spreadable have the same mechanism (e.g., avoiding spike protein-inhibiting antibodies), you can expect that old adage not to hold true over the short-term.
- slumdev 6y ago
  If anything, this is an argument against lockdowns and masking. Letting asymptomatic and barely-symptomatic people spread more-contagious but less-deadly strains would evolve the virus into a minor nuisance in short order.
  - lazide 6y ago
    No it won't - it increases the chances for mutations and variants to form, randomly, increasing the odds that one of them will be more deadly AND more infectious.
  - tsimionescu 6y ago
    That is wildly wrong. As long as the virus is spreading, there are no evolutionary pressures on it to become less deadly.
- foobiekr 6y ago
  I think this is kind of not representing the reality. _Some_ viruses _have become_ less deadly over time. Not all viruses go through this process and the selection pressure that promotes this kind of evolution is _death._ So we have no reason to believe this will occur with covid19.
  - waterhouse 6y ago
    > the selection pressure that promotes this kind of evolution is _death._ Not necessarily. Assume that people try to self-quarantine as soon as they notice symptoms. (They don't need to be 100% effective at this.) Consider "mutations that affect how quickly it spreads within your body". Those that increase said efficiency would presumably increase the likelihood of death; but they would also probably shorten the "asymptomatic spreading" period, which means they'd get selected against; this selection happens even among those that aren't dying. (Author background disclaimer: No biology beyond 9th grade.)
lazide 6y ago
That is a dangerous misunderstanding of evolutionary pressure in viruses. LONG TERM, less deadly viruses will tend to spread better because the more deadly a virus is, the more it raises stakes for the host population to remove it or prevent it , and the more it can make it apparent who has been infected. Ebola for instance justifies pretty almost any action you can imagine to contain it's spread, where we are still arguing if lockdowns or travel restrictions are the cost appropriate measure with COVID. If the time of fatality is sufficiently delayed, or the time to implement other countermeasures or recognize the situation has changed is too long, it doesn't help anyone in the short, medium, or potentially even long term - you can have massive fatalities and huge spread. The 1918 pandemic had multiple waves, with the second in particular having a much higher fatality rate than the first - 10x a typical flu season, which is what we're seeing now. This was almost certainly caused by variants, though lack of data makes it impossible to prove. [https://en.wikipedia.org/wiki/Spanish_flu https://en.wikipedia.org/wiki/Spanish_flu] A particularly nasty example [https://www.adn.com/alaska-news/science/2020/03/22/how-an-alaska-village-grave-led-to-a-spanish-flu-breakthrough/ https://www.adn.com/alaska-news/science/2020/03/22/how-an-al...] The more infections, the more likely we'll get more variants, and the more likely we'll get some that cause terrible, terrible problems - and may still be quite infectious. Long term, will the most terrible ones die out? Very likely. However, smallpox was a scourage on humanity since likely 300 BCE and up until eradication by a massive global effort in 1975, it still had fatality rates around 25-35%. So don't just assume COVID will 'evolve to harmlessness', or if it does that it would happen on a timeframe convenient for society [https://www.cdc.gov/smallpox/history/history.html https://www.cdc.gov/smallpox/history/history.html]
- slumdev 6y ago
  Trench warfare is responsible for evolving a deadly 1918 Spanish Flu virus. Soldiers with minor symptoms remained where they were, not coming in contact with many other people. The very sickest soldiers were transported by train, where the infected many other people, to hospitals, where they continued infecting many other people. It was our own attempts to care for the soldiers that caused the deadliest strains to spread and continue evolving.
  - 6y ago
anonuser123456 6y ago
A virus may become less deadly. There is no guarantee. It depends on what evolutionary options are available and what pressures are selecting mutations. Pre-symptomatic infectiousness has about the same selection pressure as low mortality rate IMO. Low risk viruses circulate well because people don’t care about transmission very much. High risk infections cause people to take precaution and thus eliminates those stains. SARS-COV-1 and MERS were that way. But pre-symptomatic infectiousness (SARS-COV-2) makes this calculus immaterial for most people; they transmit it without knowledge. This reduces the pressure on high mortality / morbidity strains / variants.
tsimionescu 6y ago
A strain that spreads more while not being significantly less deadly is much scarier than a more deadly strain that spreads less. Do the math if you don't believe me.
CyanLite2 6y ago
UK's Pandemic Team says the new strain appears to be more deadly. https://www.webmd.com/lung/news/20210125/uk-variant-may-be-more-deadly https://www.webmd.com/lung/news/20210125/uk-variant-may-be-m...

That's a mixed bag, as on one hand sure the number of dead goes down per 100, but then the number of folks infected goes up, thereby meaning the same number of dead possibly, or more people infected in hospitals.

slumdev 6y ago
SARS-CoV-2, by best estimates (0.3% mortality), is roughly 3x as deadly as the seasonal flu. The common cold is a coronavirus. It is significantly less deadly than the seasonal flu. We have every reason to believe that a more contagious but less deadly version will resemble the common cold.
- alicorn 6y ago
  Common cold is caused by a variety of viruses, only a small subset of which is coronaviruses. Look it up.
- thehappypm 6y ago
  The mortality rate is higher than .3%. .3% of New York City has already died. Unless the vast majority of New Yorkers have already contracted the virus, the mortality rate has to be substantially higher than .3%.
- tsimionescu 6y ago
  SARS1 was also a coronavirus, and it had more than 50% mortality for those infected. The virus strain tells you nothing about its mortality. SARS-CoV-2 is also only ~3x as deadly as the flu WITH UNPRECEDENTED MEASURES TO CONTAIN IT. In areas where it wasn't contain, such as the initial outbreak in Italy that overwhelmed hospitals, it was 10x or more as deadly as the flu.
paganel 6y ago
At some point the virus will run out of people to infect.
- sjg007 6y ago
  It actually will just continue to mutate and start reinfecting people as immunity wanes.
- lazide 6y ago
  Influenza certainly hasn't. It will mutate past defenses, and survive, just as seasonal coronaviruses have - unless a concerted effort occurs to completely eradicate it, and that effort is successful.

wittyreference 6y ago

Viruses are believed to become less deadly over time when being less deadly offers an evolutionary advantage in ability to spread. If being more deadly and more spreadable have the same mechanism (e.g., avoiding spike protein-inhibiting antibodies), you can expect that old adage not to hold true over the short-term.

slumdev 6y ago
If anything, this is an argument against lockdowns and masking. Letting asymptomatic and barely-symptomatic people spread more-contagious but less-deadly strains would evolve the virus into a minor nuisance in short order.
- lazide 6y ago
  No it won't - it increases the chances for mutations and variants to form, randomly, increasing the odds that one of them will be more deadly AND more infectious.
- tsimionescu 6y ago
  That is wildly wrong. As long as the virus is spreading, there are no evolutionary pressures on it to become less deadly.
foobiekr 6y ago
I think this is kind of not representing the reality. _Some_ viruses _have become_ less deadly over time. Not all viruses go through this process and the selection pressure that promotes this kind of evolution is _death._ So we have no reason to believe this will occur with covid19.
- waterhouse 6y ago
  > the selection pressure that promotes this kind of evolution is _death._ Not necessarily. Assume that people try to self-quarantine as soon as they notice symptoms. (They don't need to be 100% effective at this.) Consider "mutations that affect how quickly it spreads within your body". Those that increase said efficiency would presumably increase the likelihood of death; but they would also probably shorten the "asymptomatic spreading" period, which means they'd get selected against; this selection happens even among those that aren't dying. (Author background disclaimer: No biology beyond 9th grade.)

lazide 6y ago

That is a dangerous misunderstanding of evolutionary pressure in viruses. LONG TERM, less deadly viruses will tend to spread better because the more deadly a virus is, the more it raises stakes for the host population to remove it or prevent it , and the more it can make it apparent who has been infected. Ebola for instance justifies pretty almost any action you can imagine to contain it's spread, where we are still arguing if lockdowns or travel restrictions are the cost appropriate measure with COVID. If the time of fatality is sufficiently delayed, or the time to implement other countermeasures or recognize the situation has changed is too long, it doesn't help anyone in the short, medium, or potentially even long term - you can have massive fatalities and huge spread. The 1918 pandemic had multiple waves, with the second in particular having a much higher fatality rate than the first - 10x a typical flu season, which is what we're seeing now. This was almost certainly caused by variants, though lack of data makes it impossible to prove. [https://en.wikipedia.org/wiki/Spanish_flu https://en.wikipedia.org/wiki/Spanish_flu] A particularly nasty example [https://www.adn.com/alaska-news/science/2020/03/22/how-an-alaska-village-grave-led-to-a-spanish-flu-breakthrough/ https://www.adn.com/alaska-news/science/2020/03/22/how-an-al...] The more infections, the more likely we'll get more variants, and the more likely we'll get some that cause terrible, terrible problems - and may still be quite infectious. Long term, will the most terrible ones die out? Very likely. However, smallpox was a scourage on humanity since likely 300 BCE and up until eradication by a massive global effort in 1975, it still had fatality rates around 25-35%. So don't just assume COVID will 'evolve to harmlessness', or if it does that it would happen on a timeframe convenient for society [https://www.cdc.gov/smallpox/history/history.html https://www.cdc.gov/smallpox/history/history.html]

slumdev 6y ago
Trench warfare is responsible for evolving a deadly 1918 Spanish Flu virus. Soldiers with minor symptoms remained where they were, not coming in contact with many other people. The very sickest soldiers were transported by train, where the infected many other people, to hospitals, where they continued infecting many other people. It was our own attempts to care for the soldiers that caused the deadliest strains to spread and continue evolving.
- 6y ago

anonuser123456 6y ago

A virus may become less deadly. There is no guarantee. It depends on what evolutionary options are available and what pressures are selecting mutations. Pre-symptomatic infectiousness has about the same selection pressure as low mortality rate IMO. Low risk viruses circulate well because people don’t care about transmission very much. High risk infections cause people to take precaution and thus eliminates those stains. SARS-COV-1 and MERS were that way. But pre-symptomatic infectiousness (SARS-COV-2) makes this calculus immaterial for most people; they transmit it without knowledge. This reduces the pressure on high mortality / morbidity strains / variants.

tsimionescu 6y ago

A strain that spreads more while not being significantly less deadly is much scarier than a more deadly strain that spreads less. Do the math if you don't believe me.

CyanLite2 6y ago

UK's Pandemic Team says the new strain appears to be more deadly. https://www.webmd.com/lung/news/20210125/uk-variant-may-be-more-deadly https://www.webmd.com/lung/news/20210125/uk-variant-may-be-m...