Does Anyone Have Any Info On Treatment For Coronavirus?

I have two Great Dane puppies who got sick and I believe Corona virus is what they have. I took one of them to the vet and he said its not parvo but sent us home with meds for diarrhea and vomiting and also two IV bags to keep them hydrated. The one I took to the vet died the same day I brought him home. Now my other one is sick and I'm still giving him the meds too. We have not started on the IV yet with him since he's still drinking. I was due to give them their second set of puppy shots as they are now 4 months old. The feed store told me not to give them the puppy shots because it has a virus in it. I'm looking at the bottles though and one said Corona Virus Vaccine!!!! Should I go against what the feed store says and just give it to him? I'm desperate to keep my other puppy alive! It killed me to lose my other one. Can someone please help?