No its not a joke. George Washington conducted a mass vaccination of his troops. The cut your arm and then placed a piece of thread with small pox puss in the cut. You got a milder case of small pox. Then later they realized you could use cow pox virus so they scraped a place on your arm raw and rubbed some cow pox puss in the scrape. You got cow pox which was mild but were then immune to small pox.
I had thought it was his daughter, not the question of inoculation. Vaccines occurred post Franklin.
The mini series on John Adams illustrated Adam’s wife having the cow poke vaccine given to her and her children. Quincy was actually quite ill due to it.