Only Vaccine That Existed Before the 19th Century

This page is the CodyCross answer for the clue below from Mexico, Group 1370, Puzzle 3 (Purepecha Tribe).

Question is: Only Vaccine That Existed Before the 19th Century

and the answer is: SMALLPOX

Word Meaning:

SMALLPOX — (pathology) An acute, highly infectious often fatal disease caused by Variola virus of the family Poxviridae. It was completely eradicated in the 1970s, but still exists in laboratories. Those who survived were left with pockmarks.

Definitions from Wiktionary.

Only Vaccine That Existed Before The 19th Century - Mexico CodyCross Answers | CodyCross Solutions