During the Cold War era, there was a global effort to vaccinate people against smallpox. What was the lasting effect of this effort?

Smallpox became the first disease that infects humans to be eradicated.

Explanation:

It’s the correct answer on study island :)

a social contract.

"a social contract is an agreement between citizens and their leader where the citizens give up certain freedoms in exchange for protection. the constitution of the united states is an example of a social contract."