A while back my wife developed an allergy to the CT contrast needed for her #cancer checkups. She was going to get her Pfizer Bivalent vaccine and mentioned this new allergy. Fortunately, they checked and there is a common ingredient in her CT contrast and the vaccine. tromethamine ( trometatol or tris). Neither the pharmacist nor her oncologist were previously aware. So if you are #allergic to #CTcontrast check before taking the Pfizer Bivalent.