Debates over flu vaccination devolve into general claims about whether vaccination is safe and effective. These are fruitless.
The fruitful debates are whether each proposed vaccine is safe and effective.
In an ideal world, professionals hold those debates, yielding truth.
In our world, professional scientists are financed by political mechanisms, so they cannot objectively seek truth on political topics like this.
The reasonable person may simultaneously believe that vaccination works, while remaining skeptical of official vaccine recommendations.