Any advice or insight?

the 24 hour stomach flu has been going around here and everyone in my house has gotten it except for my 6 month old twin girls. i'm hoping and praying that they don't, but i'm really scared that they will. i'm scared that if they get it that they will get dehydrated or choke on their vomit in their sleep. do babies have a higher immunity to this? what are their chances of getting it? how can i keep them hydrated if they can't hold anything down? and how can i keep them from choking in their sleep? i'm sorry for all the questions, i'm just really worried. thanks so much for your help.