Quote from misslady113
When I was growing up, the flu wasn't a "killer". You got the flu, got sick and some chills, maybe vomiting, and got over it. But it seems nowadays that it had been labeled so deadly that we need vaccines for it every year.
Part of the problem is what people used to label as the "flu" often really was not truly influenza, but a "cold" or some other viral illness.
The only way to truly know whether what was truly the "flu" was truly influenza, is to test for it, and how often do all of those calling in with the "flu" actually get tested for it, much less test positive.
Much like pneumonia or bronchitis, the severity of the illness is actually more dependant on the causative microbe than on "bronchitis" or "pneumonia", terms that get tossed around a lot.
Influenza also includes a large number of similar but with some variations viruses. Because of their physical makeup, this group of viruses tend to mutate and alter themselves faster than most, and this alteration make it difficult to have vaccinations keep up with all the variants. This is why you get the vaccine yearly - the immunity does not "wear off" but the virus itself changes constantly. Some of these variants are likely to make one sicker than others.
Swine flu was around in the 1970's (yes, I was alive then), and the vaccine for it then was very problematic. A disproportionate number of people developed serious complications from it and that kept it from being used widely. But the disease itself faded. This new variant - there is not an effective vaccine for it.
Influenzas spread rapidly and easily. This particular one is showing an affinity for killing in the 18-50 year old range. When ID groups see this, it is a poor progonostic indicator for a pandemic.
While you may not have perceived that flu is a killer in your lifetime, that is probably due to our ability to update vaccines and better ID/healthcare. In the old days, influenza was a major killer. Please google the "Spanish Flu", basically a modern day (1917-1919) "Black Death" that killed millions beyond the deathes just from WWI. The flu epidemic alos killed large numbers of the realitively young - including servicemen that survived the war just to be killed by a virus. The increased mobility of people actually spread the disease world wide, unlike prior disease outbreaks. This is what worries the ID department.
Go out to most older graveyards - you will often see a spike in the number of graves from 1917-1920, especially among babies and children.