Funnily enough, this was the first year I got a flu vaccine, because it was being offered basically at my door and I thought it'd be useful to have before visiting family. I still managed to get sick afterwards, just instead of a flu it ended up being a particularly bad viral cold.
Not a slight against the flu shot, just a funny tidbit since it reminded me that the vaccine doesn't make me invincible from all similar disease.
While it's just an anecdote, it's more than just a funny tidbit as an increased risk of non-influenza respiratory virus is a possible side effect of flu vaccines.
"We identified a statistically significant increased risk of noninfluenza respiratory virus infection among TIV recipients (Table 3), including significant increases in the risk of rhinovirus and coxsackie/echovirus infection" [1]
That's one of the complications in assessing efficacy: if the benefit in flu vaccine is potentially quite modest (as determined by some long-running studies [2]), and it causes an increased risk of other noninfluenza respiratory viruses, then we need higher-quality, more detailed studies to understand what's happening.
But based on the discussion of the Cochrane review it seems unlikely. [3]
Not a slight against the flu shot, just a funny tidbit since it reminded me that the vaccine doesn't make me invincible from all similar disease.