There was a few centuries of experience with smallpox inoculations in China when the Europeans adopted the practice so it was known that the cases produced that way would be less severe on average — something like an order of magnitude fewer people dying from inoculation than contracting it naturally.

There's an interesting chart here showing what that looked like in Boston with the death rate falling off as inoculations picked up in the 1700s and then significantly dropping when the first vaccines were used in 1800:

https://sitn.hms.harvard.edu/flash/special-edition-on-infect...

Interesting thanks!

My wife's an AP biology teacher so we've talked about this a fair amount over the years since she's found the history is often a good hook for students.

If you want another interesting bit of history, the Balmis expedition in 1803 is fascinating, too. Smallpox was a huge problem in the New World so Jenner's discovery that cowpox protected against smallpox was of enormous interest but they didn't have an easy way to transport since the trip took longer than the 10-12 days someone would be contagious.

They ended up taking a 22 orphans and infecting them with cowpox two at a time using a sample of the pus from the previous pair, which worked well enough to reach Mexico via the Canary Islands and Puerto Rico, and then from Mexico they repeated the process with 25 new orphans all the way to the Philippines.

https://academic.oup.com/cid/article/41/9/1285/278013

Wow good thing they had a plentiful supply of orphans! Bleck! Haha thanks!

Yeah, that one hit me with a nice case of culture shock, too — imagine going to a modern IRB saying you wanted to try an new experimental treatment on poor kids and getting the response “great idea, they should be grateful for the food!”