Yes. You can donate blood two weeks after you have fully recovered from glandular fever.
If you had ‘yellow jaundice' or hepatitis associated with glandular fever, you won’t be able to donate for 12 months. When you donate again, make sure you let the interviewer know so they can request some extra tests, just to be safe.
If you’ve had contact with the saliva of someone who had glandular fever at that time (e.g. shared eating or drinking utensils, or personal items like a toothbrush), you’ll be able to donate eight weeks after the last contact.