There are two main characters.
The first one is Holly, a young widow trying to makes ends meet. She works in a small town newspaper that is struggling to survive. She is one of the constant volunteers that go in to help Vivian, who has been confined to an iron lung since she was 6 years old, the year she contracted polio.
Vivian is the second main character, who describes in detail her life in an iron lung. The small town rallys around and keep her alive.
This is a very good book, that has a surprise and satisfied ending.