Vaccines are rooted in a history of doing exactly what you are talking about. Smallpox variolation was done for hundreds of years before the development of the

Vaccines are rooted in a history of doing exactly what you are talking about. Smallpox variolation was done for hundreds of years before the development of the first vaccine. https://www.cdc.gov/smallpox/history/history.html https://www.cdc.gov/smallpox/history/history.html