I've never had a dog have a reaction, they don't even become sleepy. I also seperate the vaccines, so that might have something to do with it. It's not a bad idea to be prepared, you seem to have that covered.
Misty- Samoyed Mix, Tannor- Golden Retriever CGC
Robyn- GSD CGC, TC, Midnite-GSD CGC,TC, Brennan-Golden Retriever CGC, Batman-Husky/Greyhound , Apollo-GSD