Hi Katelyn, and welcome
As a few of us here already know firsthand that Vaccines can lead to very serious issues. Many animals, both cats and dogs alike, have bad reactions. My boy has many serious health issues (immune mediated diseases, recovered from Meningoencephalitis, grand mal seizures and other issues) and the majority are being attributed to Vaccinosis. If you search Vaccinosis, you will find many websites and links with information and lists of symptoms to watch for. If you have access to a Holisitic Veternarian, I would be seeking one out, but that's me
If it is Vaccinosis, a Holisitic Vet can help greatly by detoxifying your kitty. The longer the wait, the harder it is to detoxify. Our boy should have passed when he was a baby, but a Holistic vet saved his life. He will be 2 yrs old on Sunday
I hope everything turns out ok! Good luck to you and your kitty!! Please let us know how he's doing