The Midwest was hit harder than any other part of the country during the polio epidemics of the 1940s and '50s. Now the generation that fought polio in their youth is up against COVID-19 as senior citizens.
As her fever rose higher and higher, Marsha Engle-Reinecke began to hallucinate. She could see black birds with big, sharp beaks, she recalled — there were hundreds of them, flying at her, intent on poking out her eyes.
Viruses like influenza or HIV mutate very rapidly. The immune response from a vaccine needs to cope with this level of variability in the virus.
It's mysterious, it's dangerous and it's got parents on edge from coast to coast. It's a medical condition called acute flaccid myelitis, or AFM. Here's a look at what experts know — and don't know — about the condition.