How does new medicine cross a country's walls?

That time, that place

In late Joseon, smallpox struck perhaps one child in two. Ji Seok-yeong lost a nephew to it.

News of vaccination had already arrived; it appears in Jeong Yak-yong's writings. But knowing of a method and being able to perform it are different things. Where to obtain vaccine and how to handle it was not in any book.

Why this question

What blocked him was not knowledge but access. He had to find somewhere to learn.

What was found

He went to a Japanese hospital in Busan and studied there for two months. Returning to Seoul with three vials of vaccine and the instruments, he stopped at his wife's family home in Chungju and vaccinated his two-year-old brother-in-law — the first. Some forty villagers followed.

The next year he traveled to Japan with a diplomatic mission and learned to produce the vaccine itself, moving from receiving it to making it. He opened a vaccination station and wrote a manual to spread the method.

Then in 1882, during an uprising, people burned the station down — because it was a Western thing that had come by way of Japan.