Depends on which adult it is
Hodgkin's lymphoma.
Non-Hodgkin's lymphoma.
Acute lymphocytic leukemia (ALL)
Chronic lymphocytic leukemia (CLL)
Acute myelogenous leukemia (AML)
Chronic myelogenous leukemia (CML)
Myeloma
Once you get chickenpox, then only after a long period you will get it again. this is because your immune system knows how to respond to the pathogen the second time. so even though you get it, it won't as severe as the first time.
To maintain good personal hygiene I would brush for at least 4 to 5 minutes. I would execute this by taking time to carefully and properly brush each segment of my mouth, which includes the teeth, the gums, and the tongue. I would also bathe/shower frequently, I would execute this by seeing and taking out a specific time to do this.