What is this mysterious disease AFM all about?

A mysterious disease with symptoms resembling polio is infecting more and more children in the United States. The disease has been identified as AFM — Acute Flaccid Myelitis. AFM attacks the spinal chord, causing lesions that can paralyse children. They are often temporary, but at times the paralysis can continue for months. The onset of AFM is marked by pain and loss of strength and reflexes in the arms and legs. Facial and eyelid-drooping, slurred speech and difficulty in swallowing are some of the uncommon symptoms.
From 120 infections in 2014 the numbers have doubled to 236 in 2018. Scientists think that an enterovirus could be behind this mysterious disease.
Two enterovirus strains, A-71 and D-68 have been identified so far that causes AFM. But there could be more strains that may be responsible.
These strains are responsible for the poliovirus, which was eradicated from the US. While vaccines were used to eradicate polio, there is no known vaccine for AFM yet.