vaccinations upsetting stomach?

Fudge had her yearly booster yesterday(1 yr old). She was great yesterday with no problems eating or being sick.

We went to obedience class today which is about 30 mins drive away. She was fine there but was sick on the return journey.She stopped being sick in the car a few months ago.

It had no odour and was slimey. seemed mainly to consist of her treats from the class.She was fed tonight and had some fish left over from tea with her normal burns dry food. She has just heaved and left the whole dishful on my carpet. It was not digested at all as only just eaten.:smt088

My question is could it be the vaccinations making her sick or was it just car sickness followed by her bolting her food?

I don't know??? Could be. I'm just sorry to hear she's like this. Hopefully somebody will know I think I remember my vet saying any repercussions from the booster would show itself up immediately though? Sorry, I'm not much help! Hope she improves.