To the contrary, I heard that people vaccinated with generic flu vaccine (regardless of strain) managed to have some protection, or easier bout with Covid if infected — same goes for “BCG” (tuberculosis one avail in other countries) vaccine and pneumonia shots.
I think it does something to benefit immune system in general for those prone to high risk respiratory ailments. Again, even when the strand is not exact.
And as the aforementioned have more of a track record than Covid vaccines, these findings deserve more worthwhile exploration.
So you “heard” something. Lol
This study had nothing to do with covid.