Such infections get right into a little bottle (5)
I believe the answer is:
viral
'such infections get right into a little bottle' is the definition.
I can't tell whether this definition defines the answer.
'such infections get right into a little' is the wordplay.
'such infections' becomes 'via' (I am not sure about this - if you are sure you should believe this answer much more).
'get right' becomes 'r' (I've seen this in other clues).
'into' means one lot of letters goes inside another.
'a little' becomes 'l' (abbreviation).
'via' going around 'r' is 'vira'.
'vira'+'l'='VIRAL'
Can you help me to learn more?
(Other definitions for viral that I've seen before include "Go ___ (take off via the internet)" , "Like the common cold" , "Like pathological agents" , "Spreading rapidly" , "Of organisms causing 'flu, etc" .)