Answer: viral

AnswerCrossword Clue
VIRAL.... pneumonia
VIRALType of flu
viralof or caused by a virus
virala type of sales promotion
VIRALRapidly spreading over the internet
VIRALHow some YouTube videos go
VIRALLike some online videos
VIRALGo ... (become a meme)
VIRALHow popular videos go
VIRALSpreading fast online
VIRALLike the "Gangnam Style" video
VIRALWhat "Gangnam Style" went
VIRALSpreading like wildfire
VIRALLike some modern videos
VIRALLike mumps
VIRALWhat hot music video will go
VIRALLike a popular Internet video
VIRALLike popular videos
VIRALWhat some popular videos go
VIRALLike some word-of-mouth marketing
VIRALKind of infection
VIRALOf an infection
VIRALKind of pneumonia
VIRALOf a disease germ
VIRALOf inflective agents
VIRALLike flu
VIRALLike measles, mumps, etc.
VIRALOf an infectious agent
VIRALPertaining to an infective agent
VIRALOf a flu bug
VIRALGo ... (spread online)
VIRALLike some diseases
VIRALLike some illnesses
VIRALLike some bugs
VIRALLike the mumps
VIRALLike rabies
VIRALLike some YouTube videos
VIRALSpreading fast on YouTube
VIRALLike some marketing
VIRALLike some videos