I imagine he might not be the first person who did, the rest are just lost to history due to lack of observable / recorded results.
Earlier generations of people tended to have kind of a general, observation based understanding of that kind of thing where cause and effect was generally observed but people didn’t understand the why of it. People even very early on knew that if you caught a disease once you were less likely to catch it severely again, and they knew that if you quarantined a group of people the disease would eventually “die out”, but they had no real idea as to why in either case.
People have always been able to understand patterns like that, it’s just really hard to develop germ theory without microscopes, and they need a lot of supporting technology before you can make them.
Variolation (introducing the smallpox virus through the skin, not respiratory tract as its natural spread would be, usually leading to a milder infection and subsequent immunity) had been around for a while. Jenner’s accomplishment was successfully using the related cowpox virus to grant immunity to the smallpox virus, based on observations that people working with cattle rarely caught smallpox. This eliminated many of the downsides of variolation (eg. risk of breakthrough disease, and variolated individuals being infectious for smallpox for a while).
I imagine he might not be the first person who did, the rest are just lost to history due to lack of observable / recorded results.
Earlier generations of people tended to have kind of a general, observation based understanding of that kind of thing where cause and effect was generally observed but people didn’t understand the why of it. People even very early on knew that if you caught a disease once you were less likely to catch it severely again, and they knew that if you quarantined a group of people the disease would eventually “die out”, but they had no real idea as to why in either case.
People have always been able to understand patterns like that, it’s just really hard to develop germ theory without microscopes, and they need a lot of supporting technology before you can make them.
Variolation (introducing the smallpox virus through the skin, not respiratory tract as its natural spread would be, usually leading to a milder infection and subsequent immunity) had been around for a while. Jenner’s accomplishment was successfully using the related cowpox virus to grant immunity to the smallpox virus, based on observations that people working with cattle rarely caught smallpox. This eliminated many of the downsides of variolation (eg. risk of breakthrough disease, and variolated individuals being infectious for smallpox for a while).