When you get a vaccine it injects a controlled amount of the illness into you, so the immune system can build up an immunity. The memory cells come into play when the illness comes back.
Knowing oneself and what one wants
Answer:
Sorry to hear that! Just think good thoughts! Thanksgiving Break is almost here, so (If you live in North America) you should have some time off to yourself!
Good luck, sorry about your panic attack
C/ depression or A/ ephoria
i think is C