That means there is verifiable, reproducible evidence that vaccines, and especially flu vaccines, DO increase immunity to the particular strain vaccinated against.

Unfortunately, many people get the shot AFTER exposure, in which case it prevents nothing - just makes them think the shot caused the flu, lol, which is medically impossible.

strains are the most likely to cause trouble in the NEXT flu season doesn't mean those are the strains YOU are going to run into. This is all about herd health and statistics, and the individual can slip through the cracks. Doesn't mean vaccines don't "work".

You should still continue to get flu shots, though, because when you finally DO encounter that strain you got vaccinated for TWO years ago, your body will remember and protect you, though perhaps not quite as well as if you had recently got the shot for that strain. Immunity, once acquired, never completely goes away. Our immune systems have "memory".

I intend to get lots of flu shots between now and when I die, lol. I want my body to have weapons against as many strains as possible.

causes Fifth Disease (the 5th childhood rash virus), if it occurs in adulthood rather than childhood, is a leading cause of heart failure leading to the need for transplants.

I had a run-in with that damned thing several years ago and dodged a bullet apparently. It did leave me with the tendency to get ventricular premature contractions after consuming aspartame (which I had previously consumed uneventfully for decades). Just messed up my heart's electrical function a bit, made it more prone to arrhythmia.

So I can totally believe there is a link between flu virus and heart trouble.