[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5489283/
[2]: https://www.thelancet.com/journals/lanmic/article/PIIS2666-5...
"Only people who get tested for influenzalike illnesses—typically about 5 percent of individuals who fall ill—are tallied."
If there were a change in the way these tests were administered, for example a blaring medical bias toward another disease, that would present a significant sampling problem. That same statistician also wanted me to mention the simplest and most boring answers are usually closest to the truth.
There could be other explanations, such as: a desire to avoid Covid causes people to avoid seeking treatment, so more flu cases self resolve. OR: a fear of Covid causes more people to get tested when they're sick, and some of them may then go for flu testing before they would otherwise after coming back negative for Covid...?
Seems like the simplest answer is just "actions that have reduced the spread of one disease have also reduced the spread of another, that's historically less widespread already."
This is not the simplest answer, and the evidence that the measures have really slowed spread is extremely low except in places like New Zealand and Australia which are small islands in Oceania.
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> A bias towards testing for Covid wouldn't explain fewer cases of the flu unless those cases of the flu were coming back as Covid falsely instead of so further diagnosis was stopped.
Exactly this. I'm partial to the viral interference hypothesis, but what you don't seem to realize is that if you get infected for SARS-CoV-2 and recover in 7-14 days, you will still test PCR+ for months after. This goes into the widespread mistuning of the cycle threshold. Case in point: They tested George Floyd's corpse for COVID-19 and he was PCR+, despite having recovered from COVID-19 a couple months before. The test hit on the remnant viral debris from his long-gone infection.
Have you ever heard of this small Asian country called CHINA?
It seems far simpler, in the Occam's Razor sense, to begin with the idea that staying away from people makes it harder to get sick from other people.
Unfortunately, COVID restrictions and social distancing have become so politicized that many resist the idea that staying away from people reduces the chance of getting the flu from them, because the implication is that those measures might also have been effective in reducing COVID cases. This contradicts a political point of view and therefore some would like to dismiss it out if hand.
For example I've notice that many of those who believe precautions violated their personal liberty want to diminish the effectiveness of those precautions, which isn't necessary from a logical point of view. It is not logically inconsistent to believe these precautions violated civil liberties even if they were highly effective. It just requires a person to believe that many deaths were a reasonable price to pay.
Is it that hard to believe that not being around other people limits the chance of getting sick from other people?
These numbers seem way too low if you're talking about the prevalence of people that have been exposed to SARS-CoV-2.
Do you have a link to someone alleging this for covid? I'm worried this is spin that you picked up from a source that has an interest in opposition to covid mitigation practices.
If someone went to the COVID or flu ward and had someone cough in their face, they'd still get infected because that kind of exposure is generally too much for the innate immune system to catch.
The (let's face it, silly) notion that masks and distancing suppressed all respiratory pathogens except one is a theory with very little traction, and which will almost certainly not stand up to serious scrutiny.
At the end of the day it’s likely gonna be the result of a combination of all these factors.
Agreed! What you are describing is viral interference: population-level immune responses to one respiratory pathogen causing suppression of others.
We've seen selective suppression of influenza and all of the other four endemic coronaviruses, while SARS-CoV-2 has thrived. This is true throughout the world, including places where stringent horizontal interdictive measures were taken, in places where no such measures were taken, and in all places in between.
> At the end of the day it’s likely gonna be the result of a combination of all these factors.
I think it's very unlikely - almost impossibly so - that interdiction has played a meaningful role in population-level suppression. I don't think it will be a combination; I think it will be explained by the same clearly observed phenomenon which has been responsible for similar outcomes in the past.
Why would it not?
https://www.cdc.gov/mmwr/volumes/70/wr/mm7010e3.htm?s_cid=mm...
Although COVID-19 is definitely more virulent than influenza, it doesn't seem reasonable to just jump to the conclusion of saying "it must be the restrictions". That's definitely part of the equation, and maybe it will turn out to be the entire equation, but we don't know.
> During the study period, states allowed restaurants to reopen for on-premises dining in 3,076 (97.9%) U.S. counties. Changes in daily COVID-19 case and death growth rates were not statistically significant 1–20 and 21–40 days after restrictions were lifted. Allowing on-premises dining at restaurants was associated with 0.9 (p = 0.02), 1.2 (p<0.01), and 1.1 (p = 0.04) percentage point increases in the case growth rate 41–60, 61–80, and 81–100 days, respectively, after restrictions were lifted (Table 2) (Figure). Allowing on-premises dining at restaurants was associated with 2.2 and 3.0 percentage point increases in the death growth rate 61–80 and 81–100 days, respectively, after restrictions were lifted (p<0.01 for both). Daily death growth rates before restrictions were lifted were not statistically different from those during the reference period, whereas significant differences in daily case growth rates were observed 41–60 days before restrictions were lifted.
This is one hell of a virus, but if what we are seeing is that it still spreads quite rapidly even with all the restrictions, yet the flu, which is also quite virulent, manages to disappear, then I don't think we really have all the facts as to why it has gone away. Maybe it is just that simple?
I guess what I'm saying is that it's a bit concerning just how fast people here are willing to jump to conclusions.
Well, the CDC/WHO have kind of conditioned them, no? The CDC, at least, is starting to realign their guidelines with the data.
This isn't really quite accurate though. Before SARS-CoV-2 ever emerged, our immune systems already had defenses against it. This is because of the already-extant circulating hCoVs.
This is why something like 80% of blood samples taken before SARS-CoV-2 emerged showed T-cell cross-reactivity. From the perspective of our immune system, it was never a "novel" virus. It was novel to scientists and politicians but not to the human immune system.
Are you familiar with the concept of "R0" and that one virus may be more transmissible than another?
Flu has an R0 of about 1.5, and whatever covid's is, it's higher (last I saw was 2.5).
If we postulate that masking and distancing and similar measures act to reduce these numbers across the board, say by 0.6, that brings flu down to 0.9 and covid to 1.9. Outbreaks don't tend to stay around when their R0 is below 1, which would explain why there's hardly any flu this year and plenty of covid.
Source: I was trained as a mathematical biologist and did a bunch of work with compartmental models: https://en.wikipedia.org/wiki/Compartmental_models_in_epidem...
In this admittedly over-simplified model, beta is (per wiki) "the average number of contacts per person per time, multiplied by the probability of disease transmission in a contact between a susceptible and an infectious subject".
Social distancing reduces the average number of contacts, masking reduces the probability of transmission, and both act to reduce beta. You reduce beta, you reduce R0, you win.