The word immunisations is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 22
Highest Scoring Words With Friends™ Play In The Letters immunisations
:
Seven Letter Word Alert: (27 words)
amnions, amounts, animism, animist, anoints, atomism, mansion, mimosas, minimas, minimus, minions, misaims, mission, missuit, mitosis, nations, nonsuit, osmiums, outmans, simians, stannum, summits, summons, suntans, sustain, tsunami, unstain