What can we learn from the centuries-long quest to eradicate smallpox, once the scourge of humanity? And how did it set the stage for all vaccines to come? First we meet Edward Jenner, a doctor in 18th century Britain who learned about the folk practice of “variolation” and found a safer way to inoculate people against smallpox. Then, Donald Hopkins of the Carter Center takes us back to the 1960s in Sierra Leone, where he discovered that successfully eradicating smallpox could be a feasible goal worldwide.