My cat started sneezing after vet visit

My cat princess went for her regular checkup at the vets office and a few days later she started sneezing very badly, like 6-8 sneezes in one sitting, and she was all stuffed up. She is 15 years old. She obviously picked this up at the vets office. She was a prefectly healthy cat before she went in. In the beginning she was very lethartic, slept most of the day and the only food she would eat was chicken. A week went by and she is much better.
She is eating and drinking normally but she is still sneezing a little and her nose is still stuffed up. I am giving her lysine right now. Is there anything else I can do to get rid of this bug she caught? Do you think she needs to be put on antibiotics? Again, she is much better than last week. Does is just take a while to completly clear up? TIA.

This is probably an URI - there is no way to say for sure if she got it from the vet, or if she has Herpes and the stress of the vet made her have a flare up...
A cat can have herpes and not show any symptoms for life - it can be completely dormant - until there is a stressful situation and a lower immune system...
She is doing much better, but she is also 15... I would call the vet just to be on the safe side.
It does take a while to get it all better, but L-Lysine is very helpful!
Good luck!