Ben Sick after Annual Booster Jab

We took the boys for their jabs this morning and as soon as we got home Ben ran to the back door and then threw up
He looked so sorry for himself and the whites of his eyes were bloodshot (he often gets red eyes, being so excitable).
I don't know if it was the stress, but he didn't seem bothered by the jabs or if he maybe got car sick as we didn't have the crates in - it's only a 1 minute drive.
Going to give him cuddles now.