How come number of Covid infection rates is rising, while flu seems to be eradicated? If the measures help against the flu, why not against Covid?
I don't like appeals to authority, but this perspective that people who have spent their entire lives studying epidemiology have just got this all wrong, don't understand what they are doing, and that appeals to "common sense logic" will reveal the truth ... really irritates me.
I mean, just as a basic starting point, most people have immunological exposure to the flu, so a fairly effective method to prevent spread of the flu virus will have outsized effects on the incidence of flu (even more so if that fairly effective method is even more widely utilized by those most at risk from flu). But no humans prior to the end of 2019 had immunological exposure to SARS-COV-2, and so any "leakage" in the efforts to stop its spread will have much greater impact than with influenza.
More generally, this is really basic epidemiology, and I don't understand why you think it's so useful to question this stuff in this way.
That's very understandable but I doubt your view would survive contact with the epidemiological literature.
It's really hard to believe I know, but epidemiology papers are all terrible. They seem to always contain basic errors that any lay person can spot, and peer review doesn't catch them, nor does the editing process at supposedly prestigious journals. I've read a lot this year and by now I go in to a new paper being sure I'll encounter something stupid or crazy, because the rate of problems is just so high.
Remember that the only people who study epidemiology their whole lives are in academia, a place where being correct is less important than being published. Although it sounds absurd, 2020 has convinced me that epidemiologists and public health researchers in general know absolutely nothing about disease. They are however very good at closing ranks and claiming nobody outside their little cliques should be allowed to criticise or question them.
More generally, this is really basic epidemiology, and I don't understand why you think it's so useful to question this stuff in this way.
There's nothing basic about the claim you just made, and I'm really curious now if you yourself are an epidemiologist. Because you've gone from asserting that epidemics aren't susceptible to "common sense logic" to saying it's obvious and common sense that lockdowns/masks - which have no observable impact on case curves for COVID at all - will have outside impact on influenza.
There is actually no clear cut scientific story about Sars-Cov-2 yet. That is part of the scare.
I also don't think your logic is sound - influenca used to spread rapidly through populations in all previous years, despite of previous immunological exposure as you describe. There is no reason to assume it would spread less rapidly this year because of "previous immunological exposure".
The effectiveness of masks and social distancing also does not depend on previous immunological exposure.
But imagine the "extreme" case where excess mortality is zero - that is, even with covid19, about the same number of people die every day.
That would mean, presumably, that since covid19 causes some deaths that would not have happened historically (it doesn't matter what you think that number is) it would have to be balanced by some decrease in "more normal" deaths.
Obviously, one could propose all kinds of mechanisms that might lead to this. One could suggest that because people are either disgusted by or rallying around Trump, death rates are different. One could suggest that the impending conjuction of Saturn & Jupiter on Dec 21st has reduced death rates from non-covid19 causes. And to be sure, at present, there doesn't seem to be a particularly good way to establish this.
But it also seems rather reasonable to say that since the biggest change in human behavior at this point has been driven by attempts to contain covid19, that it is likely these changes that have caused the "balancing" decrease in non-covid19 deaths.
One obvious rebuttal is that the graph does NOT show no excess mortality. This is certainly true. But the magnitude of the it is smaller than would be expected from even the most, ahem, conservative estimates of covid19 deaths. Ergo, there is some reduction in non-covid19 deaths, and occam's razor would put changes due to anti-covid measures near the top of the list of likely causes for that.
That would not be a given assumption (under your scenario of zero excess deaths). Old people who would otherwise have died from another reason could die from Covid19 instead.
Or imagine testing everybody for the common cold, and if somebody dies with the common cold virus, they would be counted as a "common cold death". Then you would see a lot of deaths "from the common cold", without any actual change in death rates.