The excuses made for flu vaccines (there are many strains of flu after generations of different strains circulating and diverging), don't apply to COVID.
It's pretty obvious they started to redefine what vaccine does right around the time the COVID vaccine failed. The tests used to authorize the vaccines supposedly showed 95% efficiency doing just that.
There were so many narrative shifts during COVID-19 I lost count. I dunno where the blame is due. But the most disturbing thing was the stigmatization of countrarians even though "the facts" shifted left and right.
I kinda agree with you except about vaccines. The seasonal flu vaccines are nowhere close to giving immunity and predates COVID-19.