This virus is essentially an extreme variation of the common cold. They're all in the same family. Compare it to the flu virus. If you've ever looked up the flu vaccine, you'll know that the vaccine is different every year. They predict which variation of the flu virus will be most prevalent and vary the vaccine accordingly. Some of these variations tend to be worse than others. H1N1 (swine flu), which was also the prevalent virus during the Spanish Flu epidemic and the outbreak in 2009, being a good example.
This was just the year that EV-D68 had its number called. This sort of thing is not entirely unheard of for those of us working in healthcare.
In summation, it's the summer cold from hell that's seeing a sudden surge due to kids returning to school, which you noted below.
Speaking of vaccine denialism.
UGH
I work in a children's hospital. This is a good observation.