I think the 1 to 2 days is average. Some folks might take longer. Our pharmacist had to bet the shots and said she was wholloped by the second d one for several days, and she is a young healthy person, while some elderly person bets it and has no real side effects. It’s a crap shoot as to how the body will react.
I e read that folks with type o blood have less severe covid for some reason, while folks with other type blood suffer more supposedly. IF true, I wonder if that is why some folks just breeze through flus and colds, while others real.y suffer terrible, and why some can take every med under the sun and not have issues, while other folks take a baby aspirin or some typical meds and have all kinds of reactions. Had a relative who couldn’t take hardly anything without their neck swelling up, hives, trouble breathing. It was weird
You may have something there...I am blood type O and had minimum reactions to the 2nd shot.