Yes, vaccines can put cats off for a day or two.
I would do raw, save yourself a lot of money and possibly vet bills and feed your cat what it's digestive system was made to eat, not overly processed food with a vitamin pill and chemicals added. I know so many people that have switched to raw and their cat's digestive issues have cleared up.
Cat maid to:
Puddles, female Himalayan (16 yrs)
Jasper, male Ragdoll ?? (approx 9 yrs)
Sweet Pea, female silver tabby DSH (approx 7 yrs)
Rose semi feral, a cpietra rescue, female tabby (approx 6 yrs)
Snowball RIP (1991-2005)
In a cat's eye, all things belong to cats.-English Proverb
“While we are free to choose our actions, we are not free to choose the consequences of our actions.” Stephen R. Covey