Yes - that's exactly how we did it Sally. Scabivax and cross, breaking skin on inside of thigh. I still have vivid memories of it more than 20 years later. I upturned and held the sheep while my sister, who is a nurse, vaccinated them. She had done it before while helping a friend in the Dales, and being a nurse she was quite used to doing that sort of thing, so I used to get her to do injections for me as well.
The reason why the occasion is inprinted on my brain is because my sister is very accident prone, and anything to do with her and a sharp implements always had the potential for lateral damage. I therefore carefully watched every sweep of the needle to avoid getting vaccinated myself!