In the military you give up your freedom. That is why they can force you.
You don't give up your freedom per se, but you agree to adhere to the UCMJ while you're serving. The UCMJ may limit some freedoms you have as a civilian, but that's not the point I was making.
The original poster asked "when have we ever [received a cocktail of vaccinations all at once?]"
I was pointing out that there was a precedence for it.