Yeah well I had the flue shot once and had 4 flu's in a season, never again and never had a flu since.
I'd be very reluctant to get a vaccine for Covid based on my flu jab experience.
I always took the flu vaccinations as something that's in the best interests of the vulnerable.
Personally believe if you're young adult, you'd probably better off cutting the excess and loading up on healthy diet / lifestyle which helps boast you're overall immune system.
I dropped 5kgs back in March/April when I thought Covid would run wild, and managed to put it all back on by June once I thought crisis averted
Hoping the numbers as stay low as I like my food and drink