Joe and Charmion, I think when I was small, I was told the smallpox vaccine was administered via tiny cuts in the skin, so I imagined razor blades. When I was older, and got a booster, I remember seeing the single use multi-pronged poky things.

I could still find my smallpox scar, right up to when it got tattooed over.

And TB tests come in a couple different varieties. The simple one, the screening test, is another sort of poky thing. If it comes up positive, you have to get a PPD (purified protein derivative, if it matters), which is given with a needle. The screening test has occasional false positives. The PPD doesn't. The Air Force only gives the IPPD.