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It's worth noting that the 1918 flu was unique in that it killed many young, healthy people. Corona virus is more typical in that it's primarily killing the ve

It's worth noting that the 1918 flu was unique in that it killed many young, healthy people. Corona virus is more typical in that it's primarily killing the very old or otherwise ill. https://www.worldometers.info/coronavirus/coronavirus-age-sex-demographics/ https://www.worldometers.info/coronavirus/coronavirus-age-se...

Macha 7y ago
How much of that was down to the disease, compared to the conditions that "young, healthy" people would have been subjected to during a world war?
- refurb 7y ago
  The belief is that it was disease related. Younger, healthier people have more active immune systems and the Spanish flu was causing it to kick into overdrive (similar to a cytokine storm). I think the war definitely helped spread it as living conditions were rough and there was plenty of migration.
- certmd 7y ago
  From the article (as well as other places I've read similar things). "Why did so many young adults die? As it happens, young adults have the strongest immune systems, which attacked the virus with every weapon possible—including chemicals called cytokines and other microbe-fighting toxins—and the battlefield was the lung. These “cytokine storms” further damaged the patient’s own tissue." The more robust immune response was a large cause of the increased mortality.
  - dnautics 7y ago
    Iirc from my time as a biologist, we don't have any direct evidence that a cytokine storm happened and there seem to be other possible explanations for that distribution.
bcrosby95 7y ago
There were two waves to the Spanish Flu. Wave 1 started like the standard flu - it was mild, hitting mostly the old and ill, and not terribly deadly. Wave 2 is when it mutated, spread like wildfire, and killed 2% of the world population. From what I can tell they aren't completely sure what happened here. One theory I read is that WW1 reversed the trend of what happens with flu: if you had mild symptoms, you stayed on the front line. If you had severe ones, you got shipped back home on crowded trains and ships. This is in contrast with regular life - if you get a mild flu you still go out, but with severe flu you tend to stay at home. I don't think Corona virus will turn out this way. But it also doesn't seem exactly correct to say Corona virus isn't like the Spanish flu. There's lots of possible outcomes as it continues to go global. We just don't know.
- Seenso 7y ago
  >> It's worth noting that the 1918 flu was unique in that it killed many young, healthy people. > There were two waves to the Spanish Flu. Wave 1 started like the standard flu - it was mild, hitting mostly the old and ill, and not terribly deadly. Wave 2 is when it mutated, spread like wildfire, and killed 2% of the world population. That's sounds similar to the 1977 swine flu. It mainly infected people in their 20s or younger, because it was likely a lab escape of a then-extinct 1950s flu strain. Older people were unaffected because they had already acquired immunity. https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H1N1#Russian_flu https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H1N1... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4542197/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4542197/
  - jsnell 7y ago
    Thanks, that's a fascinating story I'd not heard about before.
thedudeabides5 7y ago
I don't know, but think it's reasonable to think that part of the reason for the 'W' shaped mortality curves in 1918 was not that the virulence of the 1918 flu was higher for people 20-40, but rather the incidence of infection was just much higher for all those soldiers running around in transport ships etc in Europe. Another example where we draw inferences on something phenomena, without taking into account the broader context (in this case incidence rate) https://wwwnc.cdc.gov/eid/article/12/1/05-0979-f2 https://wwwnc.cdc.gov/eid/article/12/1/05-0979-f2
ternaryoperator 7y ago
Nonetheless, the 34-year old doctor who first sounded the alarm about Covid 19 died from it--barely a month after contracting it. It's hard to know whether the elderly and the ill are simply the first wave of casualties or not. [0] https://www.theguardian.com/world/2020/feb/06/whistleblower-chinese-doctor-dies-from-coronavirus https://www.theguardian.com/world/2020/feb/06/whistleblower-...
- kelnos 7y ago
  I would expect greater morbidity and mortality among health care workers, though, so I don't think that's a data point that proves or disproves anything.
  - 01100011 7y ago
    Why? I'd figure they would get exposed more quickly, but the outcome would be, on average, the same as anyone else. Perhaps the stress of working during a health crisis exacerbates the disease, or perhaps they have a more active immune system from constant exposure to new pathogens?
    - dewy 7y ago
      The expert on NYT's The Daily podcast suggested that the load of the infection you are exposed to can influence the severity of the disease, in which case a health worker working with inflicted patients would presumably be at greater risk. However, I have neither the expertise in immunology or the time to look up sources to verify whether his statement is true. (They also suggested that he could just have been unlucky...) One fascinating thing they mentioned is that a large number of people in China smoke, especially among the elder generation that is experiencing the highest mortality rate. On the podcast, they mentioned that this is essentially a comorbidity, because your lungs are already partially shot by the time you get Covid-19 (and then viral pneumonia).
xenonite 7y ago
On the contrary. The age-grouped death rates in your link do not consider the comorbidities. Indeed, the problem with the coronavirus is that a better immune system can yield an overly intense immune reaction. If this happens, it yields a blockage of the lung capillaries. Hence, it becomes impossible to breathe. This extreme state lasts for about 2 days. This period might be only survived by utilizing a special type of breathing machine. This over-reaction of the immune system does, however, happen to a lesser amount if the immune system is in a poor condition. Hence, the coronavirus might, again, yield a survival of the weakest (like in 1918). Source: an interview with the German virologist Prof. Dr. Dr. Alexander Kekulé, here: https://www.zdf.de/uri/a4719bf9-a2c5-4c66-ad92-105cd8dcfcba https://www.zdf.de/uri/a4719bf9-a2c5-4c66-ad92-105cd8dcfcba (in German)

Macha 7y ago

How much of that was down to the disease, compared to the conditions that "young, healthy" people would have been subjected to during a world war?

refurb 7y ago
The belief is that it was disease related. Younger, healthier people have more active immune systems and the Spanish flu was causing it to kick into overdrive (similar to a cytokine storm). I think the war definitely helped spread it as living conditions were rough and there was plenty of migration.
certmd 7y ago
From the article (as well as other places I've read similar things). "Why did so many young adults die? As it happens, young adults have the strongest immune systems, which attacked the virus with every weapon possible—including chemicals called cytokines and other microbe-fighting toxins—and the battlefield was the lung. These “cytokine storms” further damaged the patient’s own tissue." The more robust immune response was a large cause of the increased mortality.
- dnautics 7y ago
  Iirc from my time as a biologist, we don't have any direct evidence that a cytokine storm happened and there seem to be other possible explanations for that distribution.

bcrosby95 7y ago

There were two waves to the Spanish Flu. Wave 1 started like the standard flu - it was mild, hitting mostly the old and ill, and not terribly deadly. Wave 2 is when it mutated, spread like wildfire, and killed 2% of the world population. From what I can tell they aren't completely sure what happened here. One theory I read is that WW1 reversed the trend of what happens with flu: if you had mild symptoms, you stayed on the front line. If you had severe ones, you got shipped back home on crowded trains and ships. This is in contrast with regular life - if you get a mild flu you still go out, but with severe flu you tend to stay at home. I don't think Corona virus will turn out this way. But it also doesn't seem exactly correct to say Corona virus isn't like the Spanish flu. There's lots of possible outcomes as it continues to go global. We just don't know.

Seenso 7y ago
>> It's worth noting that the 1918 flu was unique in that it killed many young, healthy people. > There were two waves to the Spanish Flu. Wave 1 started like the standard flu - it was mild, hitting mostly the old and ill, and not terribly deadly. Wave 2 is when it mutated, spread like wildfire, and killed 2% of the world population. That's sounds similar to the 1977 swine flu. It mainly infected people in their 20s or younger, because it was likely a lab escape of a then-extinct 1950s flu strain. Older people were unaffected because they had already acquired immunity. https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H1N1#Russian_flu https://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H1N1... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4542197/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4542197/
- jsnell 7y ago
  Thanks, that's a fascinating story I'd not heard about before.

thedudeabides5 7y ago

I don't know, but think it's reasonable to think that part of the reason for the 'W' shaped mortality curves in 1918 was not that the virulence of the 1918 flu was higher for people 20-40, but rather the incidence of infection was just much higher for all those soldiers running around in transport ships etc in Europe. Another example where we draw inferences on something phenomena, without taking into account the broader context (in this case incidence rate) https://wwwnc.cdc.gov/eid/article/12/1/05-0979-f2 https://wwwnc.cdc.gov/eid/article/12/1/05-0979-f2

ternaryoperator 7y ago

Nonetheless, the 34-year old doctor who first sounded the alarm about Covid 19 died from it--barely a month after contracting it. It's hard to know whether the elderly and the ill are simply the first wave of casualties or not. [0] https://www.theguardian.com/world/2020/feb/06/whistleblower-chinese-doctor-dies-from-coronavirus https://www.theguardian.com/world/2020/feb/06/whistleblower-...

kelnos 7y ago
I would expect greater morbidity and mortality among health care workers, though, so I don't think that's a data point that proves or disproves anything.
- 01100011 7y ago
  Why? I'd figure they would get exposed more quickly, but the outcome would be, on average, the same as anyone else. Perhaps the stress of working during a health crisis exacerbates the disease, or perhaps they have a more active immune system from constant exposure to new pathogens?
  - dewy 7y ago
    The expert on NYT's The Daily podcast suggested that the load of the infection you are exposed to can influence the severity of the disease, in which case a health worker working with inflicted patients would presumably be at greater risk. However, I have neither the expertise in immunology or the time to look up sources to verify whether his statement is true. (They also suggested that he could just have been unlucky...) One fascinating thing they mentioned is that a large number of people in China smoke, especially among the elder generation that is experiencing the highest mortality rate. On the podcast, they mentioned that this is essentially a comorbidity, because your lungs are already partially shot by the time you get Covid-19 (and then viral pneumonia).

xenonite 7y ago

On the contrary. The age-grouped death rates in your link do not consider the comorbidities. Indeed, the problem with the coronavirus is that a better immune system can yield an overly intense immune reaction. If this happens, it yields a blockage of the lung capillaries. Hence, it becomes impossible to breathe. This extreme state lasts for about 2 days. This period might be only survived by utilizing a special type of breathing machine. This over-reaction of the immune system does, however, happen to a lesser amount if the immune system is in a poor condition. Hence, the coronavirus might, again, yield a survival of the weakest (like in 1918). Source: an interview with the German virologist Prof. Dr. Dr. Alexander Kekulé, here: https://www.zdf.de/uri/a4719bf9-a2c5-4c66-ad92-105cd8dcfcba https://www.zdf.de/uri/a4719bf9-a2c5-4c66-ad92-105cd8dcfcba (in German)