My Dog has Parvo Virus.......?

Hey, my german shepherd puppy has parvo virus, and 2 days before i found out the vet gave her primary vaccinations... she ddnt eat before the vaccinations till now, so i took her to the vet, they kept her in the place, they later said she started vomiting blood, and having diarrhea, and she doesnt eat food, and is somehow depressed all the time and keeps sleeping... the vet concluded she has Parvo virus.. But since we took her to the vet early, before she started vomitting and having diarrhea will she live or no??? the vet said this virus is really hard on dogs and that the dog needs to stay with them for 5 days........:S:S:S:S:S Theyre saying then after that the dog either lives and becomes healthy again or dies.... btw how does this virus come???????