To solve this question, we need to identify the significant contribution made by Edward Jenner in 1798. Let's evaluate the provided options:
Based on this analysis, the correct answer is Vaccination. Edward Jenner's publication in 1798 concerning the smallpox vaccine was a groundbreaking achievement in medicine.
A fruit farmer presents with fever, respiratory difficulties, and neurological complications. What is the most likely diagnosis? 
Which of the following vaccines is kept at the lowest level? 