Targeted assistance to take on exhausting viral condition (5)
I believe the answer is:
aimed
'targeted' is the definition.
(I've seen this before)
'assistance to take on exhausting viral condition' is the wordplay.
'assistance' becomes 'aid' (synonyms).
'to take on' means one lot of letters goes inside another.
'exhausting viral condition' becomes 'me' (I can't explain this - if you can you should give a lot more credence to this answer).
'aid' placed around 'me' is 'AIMED'.
Can you help me to learn more?
(Other definitions for aimed that I've seen before include "Drew a bead on" , "Set sights on for a dime" , "Directed, targeted" , "Tried; pointed" , "Pointed towards" .)