Which statement best expresses the central idea of the text in WHAT IS A VACCINE

A vaccine is developed by familiarizing your body with a pathogen so that it can recognize it and keep it from spreading within you and to others.

Explanation:

Vaccines help our immune system fight infections faster and more effectively. When we get a vaccine, it sparks your immune response, helping our body fight off and remember the germ so it can attack it if the germ ever invades again. And since vaccines are made of very small amounts of weak or dead germs, they won’t make us sick.

Vaccines often provide long-lasting immunity to serious diseases without the risk of serious illness.

“asleep in his bed” is personified.

(you didn't attach a copy of the poem, but i'm answering as best as i can)

since a simile compares two unlike things using like or as, it kind of gives an item the ability to do something it can't.

example: "the player was like a tiger on the field"

in this sentence, the simile conveys the idea that the player was fast and strong, like a tiger.