Earlier quoted context omitted.
Because everyone gets the flu shot in EU, or because nobody cares?
No unless you're at risk (old person or with medical issues) you usually don't get the flu shot. The reason is to actually to build the so-called "herd immunity" I think. Same thing with antibiotics (no need to give evolutionary "ammunition" to virus and bacteria if we don't need to).
Widespread vaccination is important exactly because it produces herd immunity.