Someone so incompetent doing the injection that they don’t even bother to check the label on the vial could just as easily inject the wrong amount or inject a syringe full of air, killing the recipient.
“Mix ups”
Riiiiiight.
I do not believe there is here any “mixup.” These substitutions are likely mandated for the personnel doing the injecting. No one should be getting any sort of flu shot. Take daily vitamin D3 instead. It does the job 100% with seasonal flu (and colds) and at least mitigates the effects of WuHan flu.