Doubtful, unbelieving, dubious, unconvinced,
Carli Smith is a good name, and I have a sketch, too!
Answer:
The small pox vaccine, which was first introduced by Edward Jenner in the year 1796, was the very first successful vaccine to be made. He figured out that milkmaids who already had got cowpox did not get smallpox and found that inoculated vaccinia fought inoculated variola virus.
Explanation: