Answer:
Vaccines are samples of a specific virus. This sample gets the immune system ready and weary of the virus. Jenner used fluid from a smallpox patient and added it to a wound of another person. The person recieving the vaccination did not get the virus. Of course, vaccination technology has improved greatly. By continuosly vaccinating, the small pox virus had no vessels to infect and eventually, died off.
Step-by-step explanation: