system
Given the following post, respond as if you're commenting on Reddit:
human
Is the flu we get vaccinated for today just a variant of the 1918 Influenza?

I know the there is basically a different strain of the flu virus every year, which is why there is a new flu shot every year. Is this the result of the 1918 Spanish Influenza pandemic? 

I've been reading that Covid is more or less here to stay, and it will likely have annual variants that may require yearly boosters. Is this similar to the 1918 pandemic?

Edit: Not sure why the post is locked, but thank you everyone for your answers.
gpt
It’s worth noting that influenza has been around forever - the 1918 influenza outbreak was just one of the strains of the virus becoming especially virulent and deadly. There are also 4 major strains: one is found in cattle, and the other three go around in humans.

Influenza A and B are the ones that make humans especially ill. The 1918 flu epidemic was caused by a strain of Influenza A. Influenza A has had other mutations that has made it particularly strong and causing a lot of illness. However, remember the 2018-2019 flu season that had an uptick in illness and death? It’s because BOTH A and B were going around, and the vaccines prepped hadn’t anticipated it. Which one is going to be more prevalent is anticipated by looking at data from previous years, and the predictions were off. It happens.

So the short answer to your question is no, currently we aren’t just getting vaccinated for variants of the 1918 flu epidemic.