Which makes the flu look comparatively worse than COVID since the flu stats include widespread vaccination campaigns. For what it's worth the flu vaccine efficacy ranges from 19-60% (unlike or instance an MMR which will get you 88-97%) because there are a lot of strains of the flu (and which one is dominant in a given season varies) and it mutates regularly. COVID has shown no mutation so far (I believe the delta between viruses across the world is 15 base pairs) so a herd immunity or immunization strategy will be much, much more effective.