What is the relevance of people having immunity to the flu or taking flu vaccines?
Of course there isn't any. Sure, it would matter if this were a buzzfeed listicle about "most dangerous viruses of all time". The flu might be higher in that list. But the actual question is "given this virus, which we don't have acquired immunity to, and don't have a vaccine for, how many people will it kill, and what are reasonable steps to lower that number"?
Of course there isn't any. Sure, it would matter if this were a buzzfeed listicle about "most dangerous viruses of all time". The flu might be higher in that list. But the actual question is "given this virus, which we don't have acquired immunity to, and don't have a vaccine for, how many people will it kill, and what are reasonable steps to lower that number"?