3 ms·

> Given the reproduction number appears as the base of an exponent, I would not consider the difference "small." The difference in measurement is small, relati

by timr 6y ago

> Given the reproduction number appears as the base of an exponent, I would not consider the difference "small." The difference in measurement is small, relative to the error in measurement. Look at the error bars on the R0 estimates in that paper. Influenza runs from 1.06 to 3.4. You are trying to make micrometer inferences from a parameter where our best estimates are measured in libraries of congress.

Majromax 6y ago
I'm not a clinician or public health policymaker, so I'm operating on the balance of probabilities rather than a p=0.05 standard. If you consider the influenza estimate independent of equivalent estimates for covid, then there's a substantially greater than 50% chance that influenza's R0 is meaningfully smaller than that of the flu. If the estimates are partially dependent (i.e. methodology that gives a larger estimate for influenza would also give a larger estimate for covid), then that chance goes up further. Moreover, we also have evidence in the actual observations of epidemic dynamics. Over the southern hemisphere fall of 2020 (northern hemisphere spring), covid cases increased more rapidly than influenza cases in countries that were entering their flu seasons. That's compelling-to-me evidence that covid in fact has a larger basic reproductive number, whether that be due to a fundamental difference in the virus or just the effects of low baseline immunity. Now, your idea that the particular set of policy restrictions may be more effective against influenza than covid is very interesting. There's a basic horse sense to it, as well, since policymakers were largely operating from a playbook written for a flu pandemic. However, I do not think that "more effective" is a necessary component of the argument; "at least as effective" will do just as well given influenza's low baseline prevalence (out of season). Remember, my original point upthread was not to explain every bit of the relative epidemic curves, but instead to claim that we really ought not be surprised by the difference. I see little need to resort to specialized theories to explain the broad outline, even though I'm sure they will be helpful in the details.
- smolder 6y ago
  Your 2nd paragraph seems to have a mistake: influenza vs flu?
- timr 6y ago
  > we also have evidence in the actual observations of epidemic dynamics. Over the southern hemisphere fall of 2020 (northern hemisphere spring), covid cases increased more rapidly than influenza cases in countries that were entering their flu seasons. That's compelling-to-me evidence that covid in fact has a larger basic reproductive number Yes, we know that SARS-CoV2 increased, and influenza went away. That's trivially observed. We don't know why flu went away. To turn that observation around and say "Covid grew faster than flu, and therefore it has a higher R0, and therefore, the flu went away because {insert your favorite NPI} was just good enough to stop it" is begging the question. It could just as easily be any number of other factors that you're not accounting for. There's also a number of other faulty assumptions inherent in your logic. For starters: there's no particular reason, a priori, that a person couldn't have both flu and SARS-CoV2 in the same year.
  - watersb 6y ago
    +1 for the first constructive, correct use of the phrase "begging the question" I have encountered this year.
Pyramus 6y ago
You are dodging parent's point: > I have seen no credible evidence that typical (non-pandemic) influenza has an R0 greater than that of SARS-CoV-2. If you have a citation handy to the contrary, I'd be interested in seeing it. Even if the difference in R of influenza and SARS-Cov-2 was only 0.1 (and there is no evidence suggesting the average difference is that small) and assuming both pathogens spread in a similar fashion [1], then over time SARS-Cov-2 will fluctuate around the meta-stable point of 1.0 and as a result influenza will decrease exponentially. [1] https://virologyj.biomedcentral.com/articles/10.1186/1743-422X-5-29 https://virologyj.biomedcentral.com/articles/10.1186/1743-42...
- timr 6y ago
  I am not dodging it. As the parent noted in their own post, the best mean estimates we have for SARS-CoV2 are a fraction of a unit away from the best mean estimates we have for influenza or rhinovirus. Trying to use this tiny relative difference in fuzzy estimates of empirical parameters to make a complex causal arguments about...well, anything...is folly.
  - Pyramus 6y ago
    Sorry to be harsh here, but that's exactly what I meant by dodging: Parent asked for evidence that the R0 of influenza is higher on average than the R0 of SARS-Cov-2. If there are no studies to show, refer to an opinion of an epidemiologist or any other expert in the spread of infectious diseases. You seem to argue against a vast field of computer scientists, mathematicians, physicists, biologists, medical experts that do nothing else but study the spread of infectious diseases.
    - timr 6y ago
      > Sorry to be harsh here, but that's exactly what I meant by dodging: Parent asked for evidence that the R0 of influenza is higher on average than the R0 of SARS-Cov-2. Burden is on the parent to prove their claim, not for me to disprove claims advanced without evidence. All current estimates for R0 have wide, overlapping confidence intervals that make it impossible to differentiate them from other viruses. The best anyone can say is that Covid and influenza have similar mean R0 estimates. > If there are no studies to show, refer to an opinion of an epidemiologist or any other expert in the spread of infectious diseases. I cited just such a paper. Please refer to it.
btilly 6y ago
Last spring COVID was managing to achieve rapid spread at the same time that the flu season naturally ended. Despite the challenges in measuring R0 for both, this is pretty direct evidence that R0 is higher for COVID than for the flu.
- achenatx 6y ago
  R0 is not static. As people become immune to the current strains and the virus mutates, people will still have partial immunity to the new strains. Some people will be fully immune depending on their antibody response and the mutations. Next year it is entirely possible that the R0 of covid drops below influenza. If you introduced influenza to a naive population (i.e. native americans) you would get massive death. <<Experts believe that as much as 90 percent of the American Indian population may have died from illnesses introduced to America by Europeans>>
  - _nosewings_ 6y ago
    R0 is indeed static. It's R(t), the reproduction rate at time t, that is not static.
  - emkoemko 6y ago
    how does that work? Native Americans didn't have disease Europeans where not exposed to? Only Europeans had diseases? any info about this? very interesting
    - afrodc_ 6y ago
      Europeans did bring back disease they weren't immune to: Europeans brought deadly viruses and bacteria, such as smallpox, measles, urope. Europeans brought deadly viruses and bacteria, such as smallpox, measles, typhus, and cholera, for which Native Americans had no immunity (Denevan, 1976). yphus, and cholera, for which Native Americans had no immunity (Denevan, 1976). On their return home, European sailors brought syphilis to Europe. Although less n their return home, European sailors brought syphilis to Europe. Although less deadly, the disease was known to have caused great social disruption throughout eadly, the disease was known to have caused great social disruption throughout the Old World (Sherman, 2007) https://www.kellogg.northwestern.edu/faculty/qian/resources/NunnQianJEP.pdf https://www.kellogg.northwestern.edu/faculty/qian/resources/... (Note that I haven't read this whole thing, but wanted to find a source for my little factoid)

by timr 6y ago

Majromax 6y ago

I'm not a clinician or public health policymaker, so I'm operating on the balance of probabilities rather than a p=0.05 standard. If you consider the influenza estimate independent of equivalent estimates for covid, then there's a substantially greater than 50% chance that influenza's R0 is meaningfully smaller than that of the flu. If the estimates are partially dependent (i.e. methodology that gives a larger estimate for influenza would also give a larger estimate for covid), then that chance goes up further. Moreover, we also have evidence in the actual observations of epidemic dynamics. Over the southern hemisphere fall of 2020 (northern hemisphere spring), covid cases increased more rapidly than influenza cases in countries that were entering their flu seasons. That's compelling-to-me evidence that covid in fact has a larger basic reproductive number, whether that be due to a fundamental difference in the virus or just the effects of low baseline immunity. Now, your idea that the particular set of policy restrictions may be more effective against influenza than covid is very interesting. There's a basic horse sense to it, as well, since policymakers were largely operating from a playbook written for a flu pandemic. However, I do not think that "more effective" is a necessary component of the argument; "at least as effective" will do just as well given influenza's low baseline prevalence (out of season). Remember, my original point upthread was not to explain every bit of the relative epidemic curves, but instead to claim that we really ought not be surprised by the difference. I see little need to resort to specialized theories to explain the broad outline, even though I'm sure they will be helpful in the details.

smolder 6y ago
Your 2nd paragraph seems to have a mistake: influenza vs flu?
timr 6y ago
> we also have evidence in the actual observations of epidemic dynamics. Over the southern hemisphere fall of 2020 (northern hemisphere spring), covid cases increased more rapidly than influenza cases in countries that were entering their flu seasons. That's compelling-to-me evidence that covid in fact has a larger basic reproductive number Yes, we know that SARS-CoV2 increased, and influenza went away. That's trivially observed. We don't know why flu went away. To turn that observation around and say "Covid grew faster than flu, and therefore it has a higher R0, and therefore, the flu went away because {insert your favorite NPI} was just good enough to stop it" is begging the question. It could just as easily be any number of other factors that you're not accounting for. There's also a number of other faulty assumptions inherent in your logic. For starters: there's no particular reason, a priori, that a person couldn't have both flu and SARS-CoV2 in the same year.
- watersb 6y ago
  +1 for the first constructive, correct use of the phrase "begging the question" I have encountered this year.

Pyramus 6y ago

You are dodging parent's point: > I have seen no credible evidence that typical (non-pandemic) influenza has an R0 greater than that of SARS-CoV-2. If you have a citation handy to the contrary, I'd be interested in seeing it. Even if the difference in R of influenza and SARS-Cov-2 was only 0.1 (and there is no evidence suggesting the average difference is that small) and assuming both pathogens spread in a similar fashion [1], then over time SARS-Cov-2 will fluctuate around the meta-stable point of 1.0 and as a result influenza will decrease exponentially. [1] https://virologyj.biomedcentral.com/articles/10.1186/1743-422X-5-29 https://virologyj.biomedcentral.com/articles/10.1186/1743-42...

timr 6y ago
I am not dodging it. As the parent noted in their own post, the best mean estimates we have for SARS-CoV2 are a fraction of a unit away from the best mean estimates we have for influenza or rhinovirus. Trying to use this tiny relative difference in fuzzy estimates of empirical parameters to make a complex causal arguments about...well, anything...is folly.
- Pyramus 6y ago
  Sorry to be harsh here, but that's exactly what I meant by dodging: Parent asked for evidence that the R0 of influenza is higher on average than the R0 of SARS-Cov-2. If there are no studies to show, refer to an opinion of an epidemiologist or any other expert in the spread of infectious diseases. You seem to argue against a vast field of computer scientists, mathematicians, physicists, biologists, medical experts that do nothing else but study the spread of infectious diseases.
  - timr 6y ago
    > Sorry to be harsh here, but that's exactly what I meant by dodging: Parent asked for evidence that the R0 of influenza is higher on average than the R0 of SARS-Cov-2. Burden is on the parent to prove their claim, not for me to disprove claims advanced without evidence. All current estimates for R0 have wide, overlapping confidence intervals that make it impossible to differentiate them from other viruses. The best anyone can say is that Covid and influenza have similar mean R0 estimates. > If there are no studies to show, refer to an opinion of an epidemiologist or any other expert in the spread of infectious diseases. I cited just such a paper. Please refer to it.

btilly 6y ago

Last spring COVID was managing to achieve rapid spread at the same time that the flu season naturally ended. Despite the challenges in measuring R0 for both, this is pretty direct evidence that R0 is higher for COVID than for the flu.

achenatx 6y ago
R0 is not static. As people become immune to the current strains and the virus mutates, people will still have partial immunity to the new strains. Some people will be fully immune depending on their antibody response and the mutations. Next year it is entirely possible that the R0 of covid drops below influenza. If you introduced influenza to a naive population (i.e. native americans) you would get massive death. <<Experts believe that as much as 90 percent of the American Indian population may have died from illnesses introduced to America by Europeans>>
- _nosewings_ 6y ago
  R0 is indeed static. It's R(t), the reproduction rate at time t, that is not static.
- emkoemko 6y ago
  how does that work? Native Americans didn't have disease Europeans where not exposed to? Only Europeans had diseases? any info about this? very interesting
  - afrodc_ 6y ago
    Europeans did bring back disease they weren't immune to: Europeans brought deadly viruses and bacteria, such as smallpox, measles, urope. Europeans brought deadly viruses and bacteria, such as smallpox, measles, typhus, and cholera, for which Native Americans had no immunity (Denevan, 1976). yphus, and cholera, for which Native Americans had no immunity (Denevan, 1976). On their return home, European sailors brought syphilis to Europe. Although less n their return home, European sailors brought syphilis to Europe. Although less deadly, the disease was known to have caused great social disruption throughout eadly, the disease was known to have caused great social disruption throughout the Old World (Sherman, 2007) https://www.kellogg.northwestern.edu/faculty/qian/resources/NunnQianJEP.pdf https://www.kellogg.northwestern.edu/faculty/qian/resources/... (Note that I haven't read this whole thing, but wanted to find a source for my little factoid)