Question

1. what was jenners observation?

Explanation:

Identify Jenner's key observation

Edward Jenner observed that milkmaids seemed to be immune to smallpox. He connected this immunity to their previous exposure to cowpox, a milder disease contracted from cows. This observation is a cornerstone in the History of Vaccination.

Connect cowpox and smallpox

Using the Smallpox and Cowpox concept, Jenner noted that milkmaids who caught cowpox did not subsequently catch smallpox. This suggested that exposure to a milder disease could provide immunity against a far more lethal one.

Formulate the scientific hypothesis

Based on this observation, Edward Jenner hypothesized that intentionally inoculating someone with cowpox matter would protect them from smallpox infection, leading to the creation of the first vaccine.

Answer:

Edward Jenner observed that milkmaids who had contracted cowpox, a mild disease caught from cows, were immune to smallpox, a much more severe and deadly disease.