The FIP vaccine is the nasal one: this is taken from Dr Addie's site -
Primucell, made by Pfizer, is the only commercially available FIP vaccine in the world. Primucell is a temperature-sensitive mutant feline coronavirus which is instilled intra-nasally and gives rise to local IgA immunity and cell-mediated immunity. Primucell prevents FIP in 50-75% of cats who would have otherwise developed it, but is ineffective in cats previously exposed to FCoV. Thus, in households where FCoV is endemic (most cat breeder's households) Primucell has to be used in kittens which have already undergone the special management procedure known as early weaning and isolation, so that they are FCoV free when vaccinated.
I think I'd want to take Hunter back to the vet straight away too.