I'm going to make the Covid / Flu comparison...

[PoindexterOglethorpe]

22. No, because influenza mutates readily and steadily.

Every single year (and honestly, we mostly have China to thank for this) the influenza virus changes and sends out new mutations. Which can infect people who previously had a different version of that influenza.

Something else to keep in mind about flu. If you get the flu and recover, you have a very long-lasting immunity to any similar version. The vaccine offers only a limited protection, which is why you need to get the vaccine regularly. Keep in mind, that there's strong evidence that getting a flu shot every single year is not really the best strategy. Every other year is better.

Also, keep in mind that the main reason older people tended not to get influenza in the 1918 epidemic was that some fifty years earlier a similar type A flu pandemic occurred, and so those alive then either got it and died, got it and survived, or were already immune from it.

Personally, I don't get the flu vaccine and I don't ever worry about getting the flu, is because while growing up, I got influenza any number of times, including (I'm pretty sure) the Asian Flu in 1957. I am not about to suggest that anyone else pass on the flu vaccine. And it's possible I may change my mind at some point and start getting it. I have an exceptionally strong immune system, and so far I'm willing to trust it.

And yeah, I did get the J&J one and done shot back in March. I'm not a total idiot.