[moomin]

Okay, I just jumped down a rabbit hole trying to figure out what OP might mean. I think they’ve got it sideways. I think they’re talking about vaccinia, a virus related to cowpox (and smallpox) that form the basis of modern smallpox vaccines. The origin of the virus is, entertainingly, lost to time due to poor record keeping.

https://en.m.wikipedia.org/wiki/Vaccinia

There’s also “kinepox”, but I _think_ that’s just a different method of cowpox vaccine delivery.

[jes5199]

I’m not sure what’s sideways, how is this different from what I said?

[moomin]

Actually, you’re right. With the links it’s clear.