For me, medical procedures are never a big deal. I had two ribs removed just so I could pet small dogs easier.
When I had to be vaccinated for my trip, I assured the nurses that I give blood often, and needles are not a problem. That was before they gave me multiple shots to ward off hepatitis and yellow fever, and suddenly the lights started to go out. The last shot, for tetanus, diphtheria and pertussis, was administered while I was flat on my back, in a cold sweat. (See the above, uncomplimentary selfie.)
Luckily, the immunizations for typhoid and malaria are administered in pill form, so I can take them while standing upright. The side-effects for the anti-malarial pills include hallucinating, so only trust half the shit I blog about from India.