He’s saying the published stats could be off because of a bias toward diagnosing flu deaths as COVID deaths without testing for COVID. That is, the suggestion seems to me to be that the sampling methodology may underrepresent flu. I don’t know that I agree, but I suppose it’s possible.
The idea that 172 different strains of the Flu virus can be accurately detected and tracked, but suddenly adding a 173rd virus (COVID19) to the mix would mess up their survey seems a bit ridiculous to me.
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These flu-surveys are extremely important for designing next year's flu vaccine. There are hundreds, if not thousands, of flu strains, since that virus is constantly evolving. But the flu vaccine can only protect against 5ish strains.
Some strains (in particular: Flu TypeA) are known to spread much faster than others (ie: Flu TypeC). So even if TypeC is more common, maybe Flu TypeA is prioritized because of the risk of it becoming a pandemic a year out.
But the vast majority of samples are coming from people who will ultimately survive, but who have respiratory illness. Anyhow, scientists have considered testing bias.
“Initially, declines in influenza virus activity were attributed to decreased testing, because persons with respiratory symptoms were often preferentially referred for SARS-CoV-2 assessment and testing. However, renewed efforts by public health officials and clinicians to test samples for influenza resulted in adequate numbers tested and detection of little to no influenza virus.”
Most people don't die from flu, so that means it might be underrepresented by 0.1%.
If anything, there's less testing for flu because of covid. But nonetheless, this is sampling, not testing, the WHO performs consistent randomized sampling over time to keep the data meaningful. If they just were based on testing of reported flu cases the data would be heavily biased and basically useless in tracking the disease.
Why would a lack of COVID tests mess up the flu-tests that they're using?