@mwlucas their experience is the same for the flu. My dad got the flu shot but my mum didn't because she got the covid vaccine and forgot to get the flu shot. Both ended up getting the flu. My dad just had a runny nose and little cough for 3 days. While my mum was stuck in bed for days and feeling terrible with bad symptoms for 2 weeks!
Vaccines are not a shield, they train your body to know how to detect and kill the enemy.