Flu shots only protect you from what went around last year.
Not true. Flu vaccines prevent whatever the flu vaccine was designed to prevent. If the shot is taken early enough before exposure *and* if it takes. Individual cases don’t always take for various health and metabolic related issues. We have stocks of all significant flu strains and we watch to see what the most likely flus will be in the coming season. It’s a prediction which is often good, sometimes fair, and sometimes really bad. And that’s because the prediction has to be made months in advance to start producing vaccine stocks.
The prediction has nothing to do with what went around last year. It’s all about what they are seeing develop a few months in advance.