Not quite, new variants develop and new to adult variants will appear every few years. It's less able to spread than COVID so adults get the flu about every 5

Not quite, new variants develop and new to adult variants will appear every few years. It's less able to spread than COVID so adults get the flu about every 5 years[0]. I'm sure you've heard of Spanish flu by now, but may not have heard of Encephalitis Lethargica [1] that followed it. Luckily nothing like that has happened again and CFS is tame in comparison. But the flu still has surprises in store for us. [0] https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002082 https://journals.plos.org/plosbiology/article?id=10.1371/jou... [1] https://en.m.wikipedia.org/wiki/Encephalitis_lethargica https://en.m.wikipedia.org/wiki/Encephalitis_lethargica