I question getting the flu shot every year.
Not because I doubt vaccines; but because, depending on the year, it sometimes is just not worth it. We develop a new one every year because the strains change every year, but sometimes it changes so fast, or a different strain than the one expected spreads instead, and the shot becomes fairly useless.
I have a family member that works in one of the labs that develops flu shots and she lets us know if it's worth getting or not. Some years it's just not. But they aren't going to publicly announce NOT to get the flu shot because the public are idiots, and a good portion will take that to mean it's never worth getting.