What i don’t understand is what makes this particular type of virus potentialy more dangerous / likely to mutate into something dangerous, than any other flu ?

What i don’t understand is what makes this particular type of virus potentialy more dangerous / likely to mutate into something dangerous, than any other flu ? We don’t see this level of alarmism very often, and yet there are wordlwide epidemics of flus and other type of virus every year...