Doctors continued this daisy-chain routine until the ship reached modern-day Venezuela, where they began using the most recent pox eruption to vaccinate people in the Americas.
And then this typical rash develops, which is sort of pustular in form, and that's usually what's infectious, and this is infectious until the scabs actually fall off.
When they developed pustules, Francisco Javier de Balmis y Berenguer, the doctor who had organised the expedition, used the lymph therein to inoculate two more.
It can look different, depending on your pigment but essentially the features like flat bumps to raise bumps to pustules, to the scabs that is going to be consistent.