So I’m having trouble with this, and I’ve went through different links on Google and can’t find an answer. So they would poke into sores of people who had smallpox and then proceed to cut the patient and insert the infection directly into them. I’m not understanding why catching small pox that way would be any different than catching it naturally?
I am specifically referring to how it was done during the revolutionary war, not today’s vaccines. But wouldn’t mind knowing how those two things differ as a bonus
In: Biology
Others have described the difference. What you are describing is called variolization. Exactly where this practice developed is unclear but one of the earliest written accounts was from [Lady Mary Montagu](https://time.com/5542895/mary-montagu-smallpox/), a smallpox survivor, whose husband was sent to be the English ambassador to Turkey.
She described how she had her children variolated. They became sick eight days later (it’s almost always exactly eight days) and then quickly recovered. After this, they never got smallpox.
Variolization led to mild disease and protective immunity in ~99% of cases. ~1% developed smallpox. But against an excruciating, permanently mutilating disease with a ~50% mortality rate, the practice became popular.
It would be almost a century until Edward Jenner would attempt the practice with cowpox (or what he thought was cowpox; it turns out vaccinia has 99.7% sequence identity to horsepox). With vaccinia, the efficacy against symptomatic smallpox is ~90% and those few breakthrough cases were mild with a high rate of survival and only minimal scarring. Less than 1 in 100,000 people develop disseminated vaccinia (which is usually fatal). This is why it’s only used in military personnel and people who work with orthopoxviruses.
We have a newer one now called JYNNEOS. It uses a virus called Modified Vaccinia Ankara (MVA). This was created by taking a vaccinia strain (presumably isolated in Ankara) and passaging it on chicken eggs for hundreds of times. The resulting virus lost 20% of its genome and cannot replicate in mammal cells. So it gets into cells, makes a bunch of vaccinia surface proteins, and then goes nowhere. It’s the version that was used against monkeypox most recently with ~90% efficacy.
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